Vaccine[JOURNAL]
Sun
200 papers
Immunogenicity and safety of a SARS-CoV-2 recombinant vaccine S-268024 booster vaccination versus NVX-CoV2373: Interim results from a phase 3, multicenter, randomized, observer-blind, active-controlled study.
Nakano T, Iwata S, Oishi K … +9 more , Iguchi E, Suganuma Y, Tada Y, Saiki S, Hashimoto K, Nakajima-Yoshida H, Omoto S, Yazaki T, Sonoyama T
Vaccine · 2026 Jul · PMID 42398333 · Publisher ↗
BACKGROUND: S-268024 is a recombinant protein vaccine developed as a COVID-19 booster. METHODS: This randomized, observer-blind, phase 3 study enrolled previously vaccinated Japanese adults without a history of SARS-CoV-...
BACKGROUND: S-268024 is a recombinant protein vaccine developed as a COVID-19 booster. METHODS: This randomized, observer-blind, phase 3 study enrolled previously vaccinated Japanese adults without a history of SARS-CoV-2 infection. The noninferiority of the immunogenicity of the S-268024 booster vaccination versus NVX-CoV2373 was assessed. RESULTS: The immunogenicity population included 733 (S-268024 group: n = 368; NVX-CoV2373 group: n = 365) of 734 randomized participants. The geometric mean titer (GMT) ratio (95% confidence interval [CI]) was 1.79 (1.52-2.12), and the difference in seroresponse rate (95% CI) of SARS-CoV-2 neutralizing antibody was 7.9% (1.3%-14.4%) on day 29. The lower limit of 95% CI exceeded prespecified margins, indicating noninferior immunogenicity of S-268024 versus NVX-CoV2373; superiority in GMT was also demonstrated. Treatment-related adverse events (AEs) were numerically higher with S-268024 (92.4%) than NVX-CoV2373 (77.5%), with no treatment-related deaths/serious AEs/AEs of special interest. CONCLUSIONS: Interim analyses established noninferiority and superiority of S-268024 to NVX-CoV2373 in immunogenicity, with an acceptable safety profile.
Safety and immunogenicity of a reduced, homologous booster dose of the BNT162b2 mRNA COVID-19 vaccine: a single blind, randomized, non-inferiority follow-up trial.
Depickère S, Pannus P, Houben S … +8 more , Charles A, Heyndrickx L, Georges D, Verbrugghe M, Marchant A, Desombere I, Ariën KK, Goossens ME
Vaccine · 2026 Jul · PMID 42398210 · Publisher ↗
BACKGROUND: Reduced-dose primo-vaccination against COVID-19 demonstrated safety and immunogenicity, as evidenced by us and others. Fractional booster dosing may similarly maintain strong immunogenicity and protection whi...
BACKGROUND: Reduced-dose primo-vaccination against COVID-19 demonstrated safety and immunogenicity, as evidenced by us and others. Fractional booster dosing may similarly maintain strong immunogenicity and protection while reducing reactogenicity, improving acceptability, and conserving supplies. OBJECTIVE: To evaluate the safety and humoral immunogenicity of a reduced-dose (10 μg) versus full-dose (30 μg) BNT162b2 booster in healthy adults. METHODS: In this single-blind, randomized, non-inferiority follow-up trial in Belgium, 132 adults ≥18 years were enrolled, including participants from the REDU-VAC cohort primed with two doses of either 20 μg or 30 μg BNT162b2. Randomized participants received a 10 μg or 30 μg booster. Blood samples were collected at baseline (D0), day 28 (D28), and month 6 (M6). The primary outcome was SARS-CoV-2 anti-RBD IgG geometric mean titers (GMT) at D28. Secondary outcomes included safety, reactogenicity, anti-RBD IgG titers, neutralizing antibody titers (Wuhan, Omicron BA.1), avidity, and incidence of breakthrough infections (BTI) post D28. Mixed-effects linear models were used to assess the impacts, and a non-inferiority analysis was conducted at D28. RESULTS: No life-threatening adverse events were reported. Reactogenicity was significantly lower in the reduced-dose group (41% vs. 78%, P < 0.0001). Baseline titers were unaffected by priming dose concentration, while previously infected participants exhibited higher titers. At D28, the reduced-dose booster did not meet non-inferiority criteria for humoral immune responses. By M6, antibody titers declined across both groups, with no significant differences between reduced- and full-dose recipients. BTI incidence (69% vs. 62%, P = 0.56) and symptomatology were comparable between groups. CONCLUSIONS: The reduced-dose booster elicited moderately lower short-term humoral responses compared to the full dose, but these differences disappeared by six months and had no detectable impact on BTI rates. Combined with a significantly lower reactogenicity profile, reduced-dose regimens represent a cost-effective strategy to sustain immunity and reduce public health burdens. The study was registered at Clinicaltrials.gov (NCT04852861).
Vaccination policies for healthcare personnel in Europe, 2026.
Maltezou HC, Borg M, Botelho-Nevers E … +33 more , Brantsæter AB, Caplinskas S, Chernyshova L, Cirstea O, Civljak R, Dokova K, Falup-Pecurariu O, Filippova I, Froes F, Vitek MG, Heininger U, Hübschen JM, Josefsdottir KS, Kassianos G, Koliou M, Kyncl J, Lapii F, Ljungman P, Medić S, Molnar Z, Nitsch-Osuch A, Nohynek H, Ortiz de Lejarazu R, Rath B, Tafuri S, Townsend L, Ulbrichtová R, Van Damme P, van Essen GA, von Linstow ML, Wiedermann U, Zavadska D, Poland GA
Vaccine · 2026 Jul · PMID 42392011 · Publisher ↗
We studied current vaccination policies for health-care personnel (HCP) in 34 European countries. All (34) countries have vaccination policies for hepatitis B, 33 countries for influenza, and 22 countries for COVID-19. V...
We studied current vaccination policies for health-care personnel (HCP) in 34 European countries. All (34) countries have vaccination policies for hepatitis B, 33 countries for influenza, and 22 countries for COVID-19. Vaccination policies for measles, mumps, rubella, and varicella exist in 28, 23, 24, and 26 countries, respectively, and for tetanus, diphtheria, pertussis, and poliomyelitis in 21, 23, 23, and 15 countries, respectively. Vaccination policies for hepatitis A exist in 20 countries, and for tuberculosis (BCG vaccine), pneumococcus, herpes zoster, and human papillomavirus in 6, 6, 2, and 1 country, respectively. Lastly, 16 countries have vaccination policies for meningococcus B, 4 for meningococcus C, and 19 for meningococci ACWY (quadrivalent vaccine). Sixteen countries mandate particular vaccinations for HCP (mainly against hepatitis B and measles), including nine as a prerequisite for employment. Comparing the current vaccination policies with those we reported in 2018, we found that on several occasions vaccination programs improved and include an average of four more vaccinations. However, in several countries there are gaps in vaccination policies, particularly against measles, mumps, rubella, varicella, and pertussis. Currently, most countries have vaccination recommendations for healthcare students before entering healthcare facilities. In conclusion, European countries have more comprehensive vaccination policies for HCP compared with 2018, however there are still significant differences between countries, in terms of the number of vaccinations, target personnel, and implementation frame (recommended or mandatory vaccinations). Given the resurgence of multiple vaccine-preventable diseases in recent years, evidence-based and harmonized vaccination policies for HCP in Europe are needed to protect HCP and patients and to enhance safety in healthcare facilities.
A historical overview of the anti-vaccine movement and its public health implications.
Brown J, Brennan H, Levine CB … +1 more , Gwynn L
Vaccine · 2026 Jul · PMID 42391692 · Publisher ↗
Vaccination is one of the most effective public health interventions in history, yet resistance to vaccines has persisted across centuries. This narrative historical review examines the evolution of vaccine hesitancy and...
Vaccination is one of the most effective public health interventions in history, yet resistance to vaccines has persisted across centuries. This narrative historical review examines the evolution of vaccine hesitancy and anti-vaccine sentiment from the smallpox era to the COVID-19 pandemic. Sources were identified through PubMed and major public health organizations, including the World Health Organization and the U.S. Centers for Disease Control and Prevention, spanning the early 18th century through 2025. Across distinct historical periods, including early smallpox vaccination, mid-20th-century vaccine controversies, the 1998 Wakefield publication, and the COVID-19 pandemic, recurring themes emerge. Concerns regarding vaccine safety, distrust of institutions, and objections grounded in personal liberty have consistently shaped resistance. While these core arguments have remained stable, the mechanisms of dissemination have transformed dramatically. Modern digital platforms enable rapid, large-scale spread of misinformation, often amplified by algorithms that prioritize emotionally engaging content. The COVID-19 pandemic marked a critical inflection point, with vaccine hesitancy becoming increasingly politicized and, in some cases, economically incentivized through monetized online content. Historical examples demonstrate that both genuine safety events and misinformation can produce long-lasting effects on public trust, even after scientific refutation. This review highlights that vaccine resistance is not solely a deficit of scientific knowledge but a complex interplay of social, political, and cultural factors. Effective public health strategies must therefore extend beyond evidence dissemination to include trust-building, transparent communication, and engagement within modern information ecosystems. Sustaining vaccine confidence will require addressing both the historical roots and contemporary drivers of hesitancy.
Vaccine strategies and development before and during the 1968 H3N2 influenza pandemic.
Halwe NJ, Krammer F
Vaccine · 2026 Jul · PMID 42391691 · Publisher ↗
Nearly 60 years ago, in 1968, the global population was confronted with the emerging pandemic influenza A virus (IAV) subtype H3N2 (1968 H3N2pdm). An estimate of up to two million fatalities have been linked to 1968 H3N2...
Nearly 60 years ago, in 1968, the global population was confronted with the emerging pandemic influenza A virus (IAV) subtype H3N2 (1968 H3N2pdm). An estimate of up to two million fatalities have been linked to 1968 H3N2pdm, and the H3N2 subtype continues to circulate as seasonal IAV among humans until today. The last IAV pandemic dates back to the year 2009 but concerns about a new IAV pandemic in the near future are increasing. The global spread of H5N1 highly pathogenic avian influenza virus and its spill-over into new mammalian hosts, discovery of novel influenza A virus with zoonotic or even pandemic potential, as well as seasonal influenza viruses undergoing antigenic changes necessitate constant vigilance. Here, we highlight the proactive actions, precautionary measures and vaccination strategies used during the 1968 H3N2 IAV pandemic. Our review highlights the emergence and spread of 1968 H3N2pdm over the course of the pandemic, alongside a delineation of vaccine development before, during and after the 1968 pandemic. Updating these strategies in the context of new findings combined with our experiences during the coronavirus disease 2019 (COVID-19) pandemic is necessary to improve preparedness for the next pandemic. Influenza viruses with zoonotic potential will remain a constant threat to public health, and improving countermeasures and communication to the public is key to limit the pandemic ramifications.
Influence of correlated vaccination behaviors on estimates of COVID-19 vaccine effectiveness in older adults - VISION network, October 2023 - March 2024.
Kautz A, Yang DH, Chickery S … +35 more , Irving SA, Klein NP, Grannis SJ, Ong TC, Ball SW, DeSilva MB, Dascomb K, Naleway AL, Zerbo O, Hansen JR, Block L, Dixon BE, Rogerson CM, Fadel WF, Duszynski TJ, Barron MA, Mayer D, Chavez C, Zhuang Y, Weber ZA, Vazquez-Benitez G, Cao J, Akinsete OO, Bride D, Sheffield T, Van Otterloo J, Arndorfer J, Natarajan K, Ciesla AA, Najdowski M, Mak J, DeCuir J, Wiegand RE, Link-Gelles R, Payne AB
Vaccine · 2026 Jul · PMID 42391690 · Publisher ↗
Test negative design studies allow for COVID-19 vaccine effectiveness (VE) estimation while minimizing selection bias from healthcare seeking and testing practices. However, failure to consider correlation between vaccin...
Test negative design studies allow for COVID-19 vaccine effectiveness (VE) estimation while minimizing selection bias from healthcare seeking and testing practices. However, failure to consider correlation between vaccination behaviors may result in biased COVID-19 VE estimates. Using different methods to account for potential correlation between COVID-19, influenza, and respiratory syncytial virus (RSV) vaccination status, we investigated variability in VE estimates of the 2023-2024 COVID-19 vaccine against COVID-19-associated emergency department and urgent care (ED/UC) encounters and hospitalizations during the 2023-2024 respiratory virus season. Data were leveraged from VISION, an electronic health record-based platform. VE estimates ≥7 days post vaccination did not increase by more than 5 percentage points against ED/UC encounters and 3 percentage points against hospitalizations when accounting for influenza and RSV vaccination status or excluding influenza and RSV positive controls. As the magnitude of this influence depends on season-specific factors, ongoing monitoring is warranted.
V-safe: Summary of findings reported after COVID-19 vaccination to a US CDC active safety surveillance system through June 2023.
Myers TR, Zauche LH, Marquez PL … +3 more , McCullum I, Hause AM, Shay DK
Vaccine · 2026 Jun · PMID 42378925 · Publisher ↗
V-safe is an active surveillance system developed during the pandemic to monitor COVID-19 vaccine safety. After vaccination, US residents could enroll to receive text messages linked to health check-in surveys. Questions...
V-safe is an active surveillance system developed during the pandemic to monitor COVID-19 vaccine safety. After vaccination, US residents could enroll to receive text messages linked to health check-in surveys. Questions about symptoms and health impacts, including inability to complete daily activities, attend work or school, or receipt of medical care were asked at daily, weekly, and monthly intervals after vaccination. We describe demographics of participants compared to the vaccinated population, trends in enrollment, participation over time, and self-reported health impacts in the V-safe population during the COVID-19 pandemic. During December 14, 2020 - June 30, 2023, 9,609,282 persons completed at least one V-safe survey. Most were female (62.2%), aged 25-64 years (69.2%), and received an mRNA vaccine (95.0%). Compared to the US vaccinated population, a higher proportion of participants were non-Hispanic White or Asian and ≥ 75 years. Most registered for V-safe within the first few months after vaccination was recommended for their age group. Most completed an initial health survey within the first week after vaccination. Participation decreased for successive doses, especially among persons aged <18 years. Health impacts were reported more frequently during the first week post-vaccination, after dose 2 compared to dose 1, and among recipients of mRNA-1273 vaccine compared to recipients of BNT162b2 vaccine. Health impacts among children <12 years were reported slightly less frequently compared to adults. Seeking medical care was reported in the first week after vaccination by 0.8-1.2% of adults after doses 1-6 of an mRNA vaccine. Findings were similar to those in previous V-safe analyses and data from clinical trials. Rapidly decreasing participation during the course of the pandemic suggests that incentives encouraging survey completion in V-safe could be useful for improving safety monitoring for future emergency vaccines. V-safe continues to collect data about COVID-19 vaccines, with an emphasis on new products.
In silico selection and in vivo evaluation of scoloptoxin SSD14, Rm-inositol monophosphatase, and Rm-neprilysin as potential anti-tick vaccines.
Ullah S, Parizi LF, Almutairi MM … +2 more , Ali A, da Silva Vaz Junior I
Vaccine · 2026 Jun · PMID 42378924 · Publisher ↗
Ticks are parasitic arthropods, responsible for vectoring tick-borne pathogens to animals and humans. Globally, synthetic acaricides are used to control tick infestations; however, alternative controls methods are in dev...
Ticks are parasitic arthropods, responsible for vectoring tick-borne pathogens to animals and humans. Globally, synthetic acaricides are used to control tick infestations; however, alternative controls methods are in development. In this study, Rhipicephalus microplus (Rm)-scoloptoxin SSD14 (Rm-SSD), Rm-inositol monophosphatase (Rm-IMP), and Rm-neprilysin (Rm-Nep) proteins were characterized as anti-tick vaccine candidates. Based on physicochemical analyses, immunological and epitope prediction these three Rhipicephalus microplus proteins were selected as vaccine candidates against Rhipicephalus linnaei tick model infestation. The recombinant proteins were expressed in Escherichia coli system followed by purification using chromatography. The vaccination challenge was conducted using New Zeeland white rabbits divided into four groups (n = 4 per group): a PBS control group and three experimental groups immunized with the Rm-SSD, Rm-IMP or Rm-Nep emulsified in oil-based adjuvant. After immunization, rabbits were experimentally infested with adult and nymphal stages of R. linnaei. Following vaccination, Rm-SSD significantly reduced adult female egg laying by up to 15.96% and egg fertility by 37.45%, resulting in an overall vaccine efficacy of 47.47%. Rm-IMP significantly reduced the number of adult females by up to 22.95%, egg laying by up to 10.82%, and larval hatching by 39.91%, accounting for a total vaccine efficacy of 58.72%. Rm-Nep significantly reduced nymph numbers by 39.22% and larval hatching by up to 41.11%, with an overall vaccine efficacy of 64.20%.The results of the current study justify the use of these proteins in future as cocktail vaccine against R. microplus infesting field grazing bovines. Such strategy contributes to offering a more robust and sustainable approach for tick control under diverse climatic conditions.
Phase 1 trial of intranasal NDV-HXP-S in previously vaccinated adults.
Liu STH, González-Domínguez I, Martínez-Pérez A … +26 more , Bozkus CC, Bladh O, Broomes-Pennicott T, Jen A, Egan E, Leiva-Ortiz E, Abid A, Aguilera K, Åberg M, Bhavsar D, Yellin T, Abbad A, Singh G, Carreño JM, Adams J, Quigley C, Saxena M, Meseck M, Ceglia I, Thålin C, Weiskopf D, García-Sastre A, Palese P, Sun W, Krammer F, Aberg JA
Vaccine · 2026 Jun · PMID 42378814 · Publisher ↗
BACKGROUND: Newcastle disease virus hexapro spike (NDV-HXP-S) is a recombinant vaccine designed to elicit both systemic and mucosal immunity against SARS-CoV-2. Intramuscular vaccines protect against severe disease but p...
BACKGROUND: Newcastle disease virus hexapro spike (NDV-HXP-S) is a recombinant vaccine designed to elicit both systemic and mucosal immunity against SARS-CoV-2. Intramuscular vaccines protect against severe disease but provide limited mucosal protection. We conducted a Phase 1 trial of live NDV-HXP-S administered intranasally (IN), intramuscularly (IM), or simultaneously (IN+IM) in previously vaccinated adults. METHODS: Thirty-five healthy adults without prior COVID-19 were enrolled at a single site in New York City (Feb 2022-Apr 2024). Participants received low- or high-dose NDV-HXP-S via IN, IM, or IN+IM routes, or placebo. Safety was monitored for 365 days; immune responses in serum and saliva were measured through day 84. FINDINGS: All 35 participants completed follow-up. NDV-HXP-S was safe and well tolerated, with only grade 1-2 adverse events. Placebo recipients showed waning antibody titers, whereas NDV-HXP-S maintained or boosted serum IgG and neutralizing activity. Salivary sIgA rose modestly. Participants with low baseline CD4+ T-cell activity exhibited increases by day 28. The study was not powered for statistical significance. INTERPRETATION: Live NDV-HXP-S was safe and well tolerated in this small Phase 1 study. Exploratory immunogenicity analyses showed variable systemic and mucosal responses, supporting further evaluation of updated NDV-HXP-S formulations in larger controlled studies. FUNDING: Supported by the Icahn School of Medicine Dean's Philanthropic Fund, CastleVax Inc., Mount Sinai CTSA (UL1TR004419), and philanthropic and federal grants. TRIAL REGISTRATION: ClinicalTrials.govNCT05181709.
Effect of malaria parasitaemia on antibody responses to single-dose and two-dose HPV vaccination: results from the DoRIS dose-reduction immunogenicity trial in Tanzanian girls.
Whitworth HS, Beshir KB, Baisley KJ … +19 more , Mbwanji G, Indangasi J, Kemp T, Kamala B, Maxwell C, Hashim R, Mukerebe C, Mayaud P, Lowe B, Gabriel N, Connor N, Kapiga S, De Sanjose S, Lacey CJ, Hayes RJ, Pinto L, Changalucha J, Sutherland CJ, Watson-Jones D
Vaccine · 2026 Jun · PMID 42378813 · Publisher ↗
BACKGROUND: Human papillomavirus (HPV) vaccination is a key component of the World Health Organization's global strategy for cervical cancer elimination. The effect of malaria, a known immunomodulator, on HPV vaccine imm...
BACKGROUND: Human papillomavirus (HPV) vaccination is a key component of the World Health Organization's global strategy for cervical cancer elimination. The effect of malaria, a known immunomodulator, on HPV vaccine immunogenicity is poorly understood. This study assessed the effect of malaria parasitaemia at the time of vaccination on HPV vaccine immune responses among participants in a dose-reduction immunogenicity trial (DoRIS). METHODS AND FINDINGS: 930 HIV-negative Tanzanian schoolgirls aged 9-14 years were randomised to receive one, two or three doses of Cervarix® or Gardasil®9 (155 per arm) and followed to month (M)36. One-dose and two-dose arms participants were enrolled in a long-term extension and are included in this malaria sub-study. Dried blood spots at each vaccination visit were tested for malaria parasitaemia by quantitative polymerase chain reaction. HPV16/18 antibody responses were measured at M12, 24, 36 and 60. In the one-dose arms, there was no evidence of a difference in antibody geometric mean concentrations (GMC) or avidity index (AI) between participants with and without malaria at the time of vaccination. In the two-dose Cervarix® arm, M36 HPV16 antibody GMCs and AI results were lower in participants with malaria at either vaccination visit (HPV16 GMC ratio = 0.74, 95%CI = 0.55-0.99; AI ratio = 0.95, 95%CI = 0.91-0.99). In the two-dose Gardasil®9 arm, M36 HPV18 antibody GMCs and AI results were lower in participants with malaria at the first vaccine dose than those without malaria (HPV18 GMC ratio = 0.58, 95%CI = 0.37-0.92; AI ratio = 0.93, 95%CI = 0.87-0.99). These trends were also observed at M60. CONCLUSIONS: Whilst some effect of malaria on antibody responses was observed in the two-dose arms, these were mostly small in magnitude and unlikely to have clinical significance. Single-dose arms results are reassuring but further evaluations in larger populations would be valuable to confirm the findings. The potential for an effect of moderate or severe infection with greater parasite burden remains unclear. (NCT02834637).
Public health benefits of maternal influenza vaccination among pregnant women and infants <6 months in the United States, 2011-2020.
Morris SE, O'Halloran A, Sundaresan D … +7 more , Olson SM, Chung JR, Ellington S, Bozio CH, Iuliano AD, Biggerstaff M, Reed C
Vaccine · 2026 Jun · PMID 42378812 · Publisher ↗
Pregnant women and infants <6 months are at increased risk of influenza-associated complications. Maternal influenza vaccination during pregnancy has a strong safety record and is effective in reducing the risk of illnes...
Pregnant women and infants <6 months are at increased risk of influenza-associated complications. Maternal influenza vaccination during pregnancy has a strong safety record and is effective in reducing the risk of illness in these groups. Here, we estimate influenza disease burden, and the burden prevented by maternal influenza vaccination, among pregnant women and their infants <6 months in the United States during the 2011/12-2019/20 influenza seasons. We applied a multiplier model and compartmental framework to data that included monthly influenza-associated hospitalizations among pregnant women and infants <6 months, influenza vaccination coverage among pregnant women, and influenza vaccine effectiveness. We estimated the number of influenza-associated hospitalizations and intensive care unit (ICU) admissions among pregnant women and infants <6 months, and the corresponding number prevented by vaccination. We also simulated alternative vaccination coverage scenarios to investigate whether increased and/or earlier influenza vaccination uptake each season could have prevented additional hospitalizations. From 2011/12 to 2019/20, we estimated that 2670-10,000 influenza-associated hospitalizations and 76-486 ICU admissions occurred annually among pregnant women, and 3960-13,100 hospitalizations and 457-1830 ICU admissions occurred annually among infants <6 months. Influenza vaccination prevented an estimated 33-2440 hospitalizations and 1-166 ICU admissions annually among pregnant women, and 29-1350 hospitalizations and 4-178 ICU admissions annually among infants <6 months. We projected that increased influenza vaccination uptake would have prevented more hospitalizations among pregnant women than earlier vaccination, whereas the converse was true for infants <6 months. Together, we estimated increased and earlier vaccination uptake could have prevented an additional 12-942 influenza-associated hospitalizations annually among pregnant women and 17-1010 hospitalizations annually among infants <6 months. Our findings suggest maternal influenza vaccination reduces disease burden among pregnant women and their infants <6 months who are too young to be vaccinated.
Effectiveness and acceptability of an opt-out nudge to promote influenza vaccination among medical residents: A randomized controlled trial.
Barbaroux A, Serati I, Milhabet I
Vaccine · 2026 Jun · PMID 42378811 · Publisher ↗
Nudging has been proposed as an effective tool for promoting influenza vaccination among healthcare workers. To be successful, nudges must be considered acceptable. This paper evaluated the effectiveness and the acceptab...
Nudging has been proposed as an effective tool for promoting influenza vaccination among healthcare workers. To be successful, nudges must be considered acceptable. This paper evaluated the effectiveness and the acceptability of a nudge promoting influenza vaccination among medical residents in four hospitals in France. The hypotheses were that exposure to an opt-out nudge would increase vaccination rates and that participants would express more acceptability and a higher feeling of autonomy when exposed to the nudge. It was also expected that the feeling of autonomy would be positively correlated with nudge acceptability and with nudge effectiveness. The study's subjects were 260 medical residents. At the end of the study, 5% of residents in the nudge group reported they had not been vaccinated versus 27% in the control group, suggesting that applying the nudge to all residents could have reduced the number of unvaccinated residents by 81%. Residents found the nudge very acceptable, especially when they had been exposed to it. Residents felt that the nudge did not reduce their autonomy. The feeling of autonomy was associated with the nudge's acceptability and effectiveness. These data suggest that nudging can complement other interventions promoting vaccination, but policymakers should consider its ethical implications.
Adverse events and vaccine administration errors following RSV vaccination: Findings from the United States VAERS database, 2023-2025.
Ezeja L, Ezeala OM, Westrick SC … +1 more , Qian J
Vaccine · 2026 Jun · PMID 42372626 · Publisher ↗
INTRODUCTION: Three respiratory syncytial virus (RSV) vaccines are marketed in the U.S. for use in adults aged ≥18 years: Arexvy® (GSK), Abrysvo® (Pfizer), and mRESVIA® (Moderna), with only Abrysvo® approved for use duri...
INTRODUCTION: Three respiratory syncytial virus (RSV) vaccines are marketed in the U.S. for use in adults aged ≥18 years: Arexvy® (GSK), Abrysvo® (Pfizer), and mRESVIA® (Moderna), with only Abrysvo® approved for use during pregnancy. This study describes post-marketing adverse event (AE) reports after RSV vaccination and detected reporting risk signals of administration-related errors using the U.S. Vaccine Adverse Event Reporting System (VAERS). METHODS: We searched the VAERS database for reports of AE following RSV vaccination during January 1, 2023 - December 31, 2025. We assessed the characteristics of these reports and described the most commonly reported AEs by RSV vaccine brand. The top 15 most frequently reported AEs and top 10 most frequently reported vaccine administration errors were examined for Arexvy® and Abrysvo®. Disproportionality analyses (reporting odds ratio) were conducted to detect disproportionate reporting risk signals of vaccine administration errors (SAS version 9.4). RESULTS: During the study period, VAERS received 8365 AE reports following RSV vaccination; most were after Arexvy® (68.2%) and Abrysvo® (29.9%). The 5 most frequently reported AEs for Arexvy® were extra dose administered (15.0%), injection site pain (12.8%), injection site erythema (11.3%), injection site swelling (9.0%), and pain (9.0%); while for Abrysvo®, they included exposure during pregnancy (10.6%), extra dose administered (9.9%), headache (7.7%), fatigue (7.7%) and injection site pain (7.3%). Although not recommended for use during the study period, 4.2% (n = 244) of reports after Arexvy® vaccination were from individuals <50 years old; 6.6% (n = 375) were exposure during pregnancy. Both Arexvy® and Abrysvo® exhibited significant signals for vaccine administration errors such as extra dose administered and product administered to patient of inappropriate age. CONCLUSIONS: Most AE reports following RSV vaccination were non-serious. The potential misuse of Arexvy® during pregnancy and excess dose for both Arexvy® and Abrysvo® highlight potential gaps in healthcare provider education and vaccine record retrieval.
Protocol for a phase 3, randomized, double-blind clinical trial evaluating the safety and immunogenicity of the MVA-BN® vaccine against mpox in children aged 4 to less than 24 months in the Democratic Republic of the Congo: Data to guide future paediatric vaccination strategies.
Tshilumba SM, Ruiz PM, Matuvanga TZ … +16 more , Lemey G, Kimbulu P, Azoum MA, Salloum M, Kasereka G, Mitashi F, Bikioli F, Muteba D, Bisumba A, Van Damme P, Muhindo-Mavoko H, Jordan E, Van Geertruyden JP, Maketa V, Mitashi P, Larivière Y
Vaccine · 2026 Jun · PMID 42372625 · Publisher ↗
INTRODUCTION: This article describes the protocol of the PregInPoxVac vaccine trial, evaluating the safety and immunogenicity of two MVA-BN vaccination regimens (full-dose and half- dose) administered subcutaneously with...
INTRODUCTION: This article describes the protocol of the PregInPoxVac vaccine trial, evaluating the safety and immunogenicity of two MVA-BN vaccination regimens (full-dose and half- dose) administered subcutaneously with a 28-day interval in infants aged 4 to <24 months old. Non-inferiority of the full dose and half dose regimens will be compared to adults receiving a full dose regimen as part of the POX-MVA-045 study (ClinicalTrials.govIdentifier:NCT06549530). The PregInPoxVac study is being conducted in Boende, Tshuapa Province, Democratic Republic of the Congo (DRC), a mpox-endemic area; the POX-MVA-045 study is being conducted in Kinshasa, DRC, and Entebbe, Uganda. This is a randomized, double-blind, phase 3 trial assessing two dosing regimens in infants, with immunogenicity and safety compared to a predefined adult reference dataset. METHODS: This is a phase 3, randomized, double-blind vaccine trial. A total of 344 healthy children aged 4 to <24 months will be enrolled at the Boende General Referral Hospital in the DRC. Participants will be randomized in a 1:1 ratio to receive either two full doses (0.5 mL) or two half doses (0.25 mL) of the MVA-BN® vaccine, administered subcutaneously 28 days apart. The primary objective is to evaluate the immunogenicity and safety of the paediatric vaccination regimen compared to the reference adult regimen, as defined in the POX-MVA-045 vaccine trial. Immunogenicity will be assessed through a hierarchical non-inferiority analysis of neutralizing antibody responses comparing full-dose and half-dose regimens in infants with the full-dose adult reference cohort. As a secondary analysis, the immunogenicity and safety observed in full dose infants will be compared to half dose infants. Additionally, total binding antibodies against vaccinia will also be compared between infants and adults as a secondary objective. Solicited adverse events (AEs) will be recorded for 7 days following each injection or until resolution of the event. Unsolicited AEs will be recorded for 28 days following each injection or until resolution of the event. Medically attended AEs (MAAEs), AEs of special interest (AESIs), serious AEs (SAEs) will be recorded from signing of the informed consent through 12 months after the second dose. Participant enrolment was conducted between 29 May and 30 October 2025. ETHICS AND DISSEMINATION: The protocol was approved by the Antwerp University Hospital Committee for Medical Ethics (Approval No. 2025-7480), the National Health Ethics Committee of the DRC Ministry of Health (CNES) (Approval No. 641/CNES/BN/PMMF/2025) and by the Congolese Pharmaceutical Regulatory Authority (ACOREP:Approval No. 556/ACRP/DG/CAB/D15/2025). The trial has been registered on ClinicalTrials.gov (Identifier: NCT06844487).Written informed consent will be obtained from all parents or legal guardians prior to any study-related procedures being performed. The results will be published in peer-reviewed scientific journals and presented at national and international conferences.
Human systemic and mucosal immune responses support further exploration of a Klebsiella pneumoniae protein-based vaccine.
Campo JJ, Pearse O, Zuza AM … +13 more , Oberai A, Siyabu P, Tewesa E, Gadama L, Lissauer S, Lissauer D, Teng AA, Pablo JV, Edgar JM, Shandling AD, Kawaza K, Feasey NA, Heinz E
Vaccine · 2026 Jun · PMID 42372624 · Publisher ↗
BACKGROUND: Neonatal sepsis caused by Klebsiella pneumoniae is a major cause of under-five mortality in sub-Saharan Africa, and the rapid increase of infections caused by bacteria resistant to most or all available antim...
BACKGROUND: Neonatal sepsis caused by Klebsiella pneumoniae is a major cause of under-five mortality in sub-Saharan Africa, and the rapid increase of infections caused by bacteria resistant to most or all available antimicrobials severely limits treatment options. An effective, maternally-administered vaccine could make a substantial reduction in neonatal sepsis and associated negative outcomes, as well as reduce the overall need for antimicrobials, a key driver of antimicrobial resistance. This exploratory, hypothesis-generating pilot study investigated the potential for a maternally administered protein-based vaccine to provide neonatal protection via antibodies transferred transplacentally and through breastfeeding. METHODS: A case-control pilot study of mother and baby dyads was designed with 20 neonates developing K. pneumoniae sepsis and 95 uninfected control neonates to analyse breastmilk IgA, cord blood IgG and maternal serum IgA and IgG antibodies on a protein microarray, and case isolates were whole-genome sequenced. RESULTS: Following computational analyses to identify surface-exposed candidates, we generated a protein microarray with 161 selected K. pneumoniae proteins representing 152 unique genes. The analysis of breastmilk IgA, cord blood IgG and maternal serum IgA and IgG identified a set of proteins eliciting antibody responses, some correlated with lack of K. pneumoniae sepsis which could indicate the presence of potentially protective antibodies. CONCLUSIONS: This is an essential first step in exploring surface protein accessibility, despite the large capsule. We highlight fimbrial structures, conjugative pili, and small lipoproteins associated with large outer membrane complexes as potential protein vaccine targets.
Corrigendum to "Immunogenicity and safety of a quadrivalent recombinant influenza vaccine manufactured in Iran (FluGuard) in volunteers aged 18-60 years: A double-blind, non-inferiority, randomized controlled trial" [Vaccine 42(9) (2024) 2254-2259].
Yadegarynia D, Keyvanfar A, Keyvani H … +3 more , Tehrani S, Sali S, Abolghasemi S
Vaccine · 2026 Jun · PMID 42365746 · Publisher ↗
Abstract loading — click title to view on PubMed.
Innovative webinar-based training to support evidence-to-recommendation decision-making by national immunization technical advisory groups: multi-country experience with hexavalent vaccines.
Torre L, Hadler SC, Hopkins KL … +3 more , Sommers T, Best T, Ndiaye S
Vaccine · 2026 Jun · PMID 42365745 · Publisher ↗
Since endorsement of the Global Vaccine Action Plan, and continued emphasis under Immunization Agenda 2030, the number of functional National Immunization Technical Advisory Groups (NITAGs) has expanded rapidly, creating...
Since endorsement of the Global Vaccine Action Plan, and continued emphasis under Immunization Agenda 2030, the number of functional National Immunization Technical Advisory Groups (NITAGs) has expanded rapidly, creating increased demand for training in evidence-informed decision making. To support timely national policy decisions relating to immunization, innovative and flexible training approaches are needed. This paper describes and evaluates a novel, webinar-based Evidence-to-Recommendation (EtR) training designed to support NITAGs in developing evidence-based recommendations for transitioning from pentavalent plus inactivated polio vaccine to combined hexavalent vaccines. Between January and June 2025, a five-part EtR webinar series focused on the hexavalent vaccine transition was delivered to countries, primarily within the WHO African Region, who qualify to receive financial and technical support from Gavi, the Vaccine Alliance, to help introduce new vaccines and strengthen their immunization systems. The series emphasized identification of evidence across EtR domains, and a cohort-based model to facilitate regional peer learning. Effectiveness of the webinar series was assessed through electronic post-webinar surveys and virtual key informant interviews. NITAGs from 32 countries participated in one or more webinars, including nine in three or more. Across participating countries, participants consistently rated the webinars as useful, particularly valuing country experiences and practical guidance on EtR domains. Qualitative feedback highlighted peer learning as the most valuable component of the webinar series, alongside practice guidance on EtR domains such as feasibility and resource considerations, and NITAGs showed strong interest in continued technical support, practical, peer-to-peer learning or "twinning", and operational guidance for hexavalent vaccine introduction.
Under-vaccination as a systems failure: A Monte Carlo simulation of the 2025 CDC/ACIP hepatitis B birth-dose policy shift and multi-level intervention packages, 2025-2035.
Gandhi V, Kinariwala K, Kesling GL
Vaccine · 2026 Jun · PMID 42365679 · Publisher ↗
BACKGROUND: In 2025, the CDC/ACIP reclassified the hepatitis B (HBV) birth-dose recommendation from universal vaccination to a shared clinical decision-making (SCDM) model. U.S. adult HBV vaccination rates remain stagnan...
BACKGROUND: In 2025, the CDC/ACIP reclassified the hepatitis B (HBV) birth-dose recommendation from universal vaccination to a shared clinical decision-making (SCDM) model. U.S. adult HBV vaccination rates remain stagnant at 30-32%, reflecting systemic delivery failures. The projected impact of this policy shift and whether multi-level interventions can protect vulnerable populations remains unquantified. METHODS: We developed a Monte Carlo simulation (N = 50,000 iterations) projecting U.S. vaccination outcomes from 2025 to 2035 across five scenarios: (A) policy-only; (B) hospital standing orders; (C) EHR-driven clinic workflow optimization; (D) community health worker (CHW) outreach; and (E) a comprehensive multi-level intervention. Parameters derived from published surveillance data, clinical trials, and implementation studies. Primary outcomes included birth-dose coverage, adult series completion, perinatal infections, and chronic HBV cases. RESULTS: Under Policy-Only (Scenario A), birth-dose coverage fell from 91.8% to 75.7% by Year 10, yielding 19,306 perinatal HBV infections (95% CrI: 15,851-24,279) and 17,376 chronic cases. The comprehensive intervention (Scenario E) maintained birth-dose coverage at 89.7% (95% CrI: 80.3-97.0%) and adult vaccination at 95.0% by Year 10, reducing perinatal infections to 1952 (95% CrI: 729-3869)-equivalent to 10.4 million additional adult vaccinations over Policy-Only. Maternal screening sensitivity was the strongest predictor of perinatal outcomes (r = -0.909). CONCLUSIONS: The 2025 SCDM policy, absent structural safeguards, is projected to reduce perinatal HBV protection and widen health disparities over the next decade. A comprehensive multi-level intervention-combining standing orders, EHR-driven workflows, and CHW outreach-is necessary to offset projected harm. Policy revision alone is insufficient; protecting vulnerable populations requires fundamental redesign of healthcare delivery.
A prematurely terminated phase 2, randomised trial to evaluate immunogenicity and reactogenicity of a single versus two-dose primary vaccination regimen of the mRNA vaccine BNT162b2 in previously SARS-CoV-2 infected children 5-11 years old (CoVacc trial).
Prat-Aymerich C, Yeghiazaryan L, Pathirana RD … +15 more , Gautier V, Garcia Leon AA, Saini G, Loens K, Cox RJ, Formiconi E, O'Reilly S, van Hulst K, Nijland J, Cornely OA, Mallon P, Posch M, Bruijning-Verhagen P, CoVacc Study Group of the VACCELERATE Consortium www.vaccelerate.eu., CoVacc Site investigators:
Vaccine · 2026 Jun · PMID 42364277 · Publisher ↗
BACKGROUND: This open-label randomised phase 2 study aimed to determine whether a single versus two-dose BNT162b2 primary vaccination regimen in children 5 to 11 years old with prior SARS-CoV-2 infection was non-inferior...
BACKGROUND: This open-label randomised phase 2 study aimed to determine whether a single versus two-dose BNT162b2 primary vaccination regimen in children 5 to 11 years old with prior SARS-CoV-2 infection was non-inferior in terms of immunogenicity and superior in terms of safety and reactogenicity. METHODS: Participants were randomly assigned (1:1) to receive either one or two doses, spaced 3 to 12-weeks. The primary endpoint was geometric mean ratio (GMR) of neutralizing antibodies against wild-type SARS-CoV-2 at 28 days post-vaccination with non-inferiority margin defined as a 1.5-fold change in geometric mean titers (GMT). Secondary endpoints included safety and reactogenicity profile and immunogenicity up to 12 months against wild-type and Variants of Concern (VOCs). RESULTS: In total 31 participants from 3 European countries (median age 9, IQR7-10) were enrolled from May 2022 to January 2024, when the trial was prematurely terminated due to declining interest in COVID-19 vaccination among age-eligible children. Of these, 15 received two doses, and 16 received one. At day 28, GMT of neutralizing antibodies against wild-type SARS-CoV-2 was 1801.1 IU/mL(95%CI:1357.9-2388.9) in the two-dose arm and 1715.5 IU/mL(95%CI:1064.2-2765.4) in the single-dose arm. However, the non-inferiority of the single-dose could not be demonstrated (GMR:0.9; 95%CI:0.5-1.6). Titers remained above 100 IU/mL in both groups at 6 and 12 months. Both schedules elicited high anti-RBD IgG titers against wild-type and neutralizing titers against BA.5 variant at day 28. Eight participants (53%) in the two-dose arm and five (31%) in the single-dose reported a systemic adverse event grade ≥ 2 (P = 0.18) within 7 days of vaccination. CONCLUSIONS: Both regimens induced robust and sustained immune responses consistent with the possibility that, in children with prior infection, a single dose functions immunologically as a booster of the humoral response. However, the premature termination renders the primary non-inferiority comparison statistically underpowered. The vaccine was well tolerated in both groups. EudraCT registration: 2021-005043-71.
Longitudinal changes in the antibody responses and adverse reactions across successive SARS-CoV-2 mRNA vaccinations from the primary series to the JN.1-adapted booster in hospital employees: A 4-year prospective cohort study.
Tani N, Sato T, Goto T … +6 more , Harada Y, Horiuchi T, Akashi K, Shimono N, Ikematsu H, Chong Y
Vaccine · 2026 Jun · PMID 42361783 · Publisher ↗
BACKGROUND: Longitudinal profiles of immunogenicity and reactogenicity across successive SARS-CoV-2 vaccinations, including the XBB.1.5- and JN.1-adapted boosters, remain incompletely characterized. It also remains uncle...
BACKGROUND: Longitudinal profiles of immunogenicity and reactogenicity across successive SARS-CoV-2 vaccinations, including the XBB.1.5- and JN.1-adapted boosters, remain incompletely characterized. It also remains unclear whether the previously observed association between post-vaccination fever and antibody responses persists with these newer boosters. METHODS: In this prospective open-cohort study of healthcare workers, participants received a primary series followed by first wild-type (WT) booster, BA.4/5 bivalent booster, and subsequent XBB.1.5 and JN.1 boosters. Serum samples collected pre- and post-vaccination were assayed for anti-receptor binding domain (RBD) IgG. Adverse reactions were recorded using a self-reported diary. RESULTS: A total of 492 participants provided at least one serum sample (2548 samples in total), with data availability varying across vaccination time points and complete follow-up across all time points limited. Peak WT-specific anti-RBD IgG titers plateaued with successive boosters, irrespective of SARS-CoV-2 infection history. However, XBB.1.5 and JN.1 boosters increased target-strain-specific IgG more than WT-specific IgG, resulting in a 1.5-fold increase in the variant-to-WT IgG ratio. This ratio persisted through day 350 after the XBB.1.5 booster. Local reactions showed no significant change, whereas systemic reaction frequencies declined significantly with successive boosters. The proportion of participants with fever ≥38 °C decreased from 26.2% after the first booster to 5.0% after the XBB.1.5 booster and 8.3% after the JN.1 booster, and the overall reaction severity also decreased. In multivariable regression, fever remained positively associated with post-vaccination IgG titers across boosters; for the XBB.1.5 booster, the association was positive but nonsignificant (p = 0.069), likely due to the low fever incidence. CONCLUSIONS: Repeated boosters yielded a plateau in peak WT-specific anti-RBD IgG titers, while variant-adapted boosters elicited stronger responses against their target strains than against WT. Systemic adverse reactions progressively declined, whereas local reactions remained stable across successive boosters. Post-vaccination fever was significantly associated with higher anti-RBD IgG titers across multiple vaccinations.
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