Vaccines

Objectives To evaluate the impact of COVID-19 vaccination on the prevention of long COVID (LC) in the Omicron era through an updated systematic review and meta-analysis. Methods We performed an update of our previously published systematic review and meta-analysis of vaccination and LC risk (searches between 1 January 2022 and 1 March 2024). Databases (Embase, MEDLINE, PubMed, Europe PMC, LILACS, Cochrane COVID-19 Study Register) were searched for studies published between 1 March 2024 and 13 July 2026. Observational studies assessing the impact of vaccination on the risk of LC four or more weeks after SARS-CoV-2 infection were included. Vaccines were restricted to those centrally authorised in the European Union. Random-effects meta-analyses, restricted to adults, were performed to calculate pooled odds ratios (OR) of LC in three comparisons: vaccinated (any dose) versus unvaccinated; booster vaccination versus unvaccinated; and booster vaccination versus primary course vaccination only. Results Nineteen new studies were identified, of which ten were included in the updated meta-analyses alongside eight studies from the original review. The pooled OR of LC in vaccinated adults (any dose) versus unvaccinated was 0.75 (95% confidence interval [CI] 0.67-0.84; 13 studies). ORs were also lower for booster vaccination versus unvaccinated (0.73; 95% CI 0.65-0.82; 6 studies), and booster vaccination versus primary course vaccination (0.63; 95% CI 0.53-0.75; 6 studies). Significant associations between vaccination and lower LC odds were observed in subgroup analyses of mRNA-only vaccination and LC outcomes three or more months after infection. Conclusions This updated review and meta-analysis reinforces our previous finding that vaccination may reduce the burden of LC in the Omicron era, with booster doses potentially providing additional protection. Although evidence in high-risk groups now prioritised for vaccination in most countries remains limited, these findings clearly demonstrate the benefits of vaccination and support current seasonal vaccination strategies.

Introduction:Although the COVID-19 pandemic clearly showed the potential consequences of a world without vaccinations, vaccine hesitancy is likely to be more pronounced in the post-COVID-19 era. The introduction of human papillomavirus (HPV) vaccines in this context is likely to raise particular concerns. In Tunisia, decision-makers have prioritized the introduction of HPV vaccine into the immunization schedule. This study assessed individual barriers and facilitators to HPV vaccine acceptability in Tunisia, with the aim of guiding an effective communication strategy for HPV vaccination campaigns in Tunisia and neighboring countries in a post-pandemic context.Methods: Using a qualitative design, we conducted 14 focus groups (FG) with healthcare professionals (HCP) (N=32) and community representatives (CR) (N=89) in five regions of the country. The discussion followed a semi-structured guide designed on the basis of vaccine hesitancy determinants matrix. Transcripts were deductively analyzed according to the 'social processes' and 'thinking and feeling' of the behavioural and social drivers (BeSD) Framework. Inductive approach was used to analyze participants suggestions for promoting HPV vaccination.Results:The FG analysis demonstrated that the historically strong trust in vaccination in Tunisia has weakened after the COVID-19 pandemic. Mistrust of health system and experts, the pandemic management and vaccine mandates measures had negative influence on the vaccine attitudes in a post pandemic Tunisian context. Persistent concerns about COVID-19 vaccines safety were frequently intertwined with widespread distrust of pharmaceutical companies and their profit motives, perceived as imposing inequitable access and lower-quality vaccines on countries in the Global South. These concerns fueled confusion about vaccines side effects. The weakening of immunity was recurring, as well as memory issues, impacts on fertility, and sudden deaths. Regarding information, our research revealed that although digital platforms were perceived as widely used, a significant part of the population interviewed considered public TV channel, as the most reliable source of health information.Conclusions: Emphasizing how the pandemic has shaped individual and collective perceptions and attitudes toward vaccination, our findings underline the importance of leveraging lessons learned from the pandemic to develop a context tailored and coherent communication strategy for successful HPV vaccine implementation.

Introduction Respiratory syncytial virus (RSV) is an important cause of respiratory disease in older adults and adults with chronic medical conditions, contributing substantially to the healthcare burden in Italy. The availability of effective RSV vaccines provides an opportunity to reduce RSV-related morbidity, mortality, and healthcare costs in populations at high risk of severe disease. This study evaluates the potential public health impact and cost-effectiveness of vaccination using mRNA-1345 administered as a single dose compared with no vaccination in Italian high-risk adults aged 60-74 years and all adults aged [≥]75 years. Methods A static decision-analytic model was developed to project clinical and economic outcomes over a 5-year time horizon. Economic outcomes were evaluated from the Italian National Health Service (Servizio Sanitario Nazionale, SSN) perspective. Model inputs were informed by the most recent Italian epidemiological, clinical, and economic evidence, supplemented by published international data when necessary. Deterministic, probabilistic, and scenario analyses were conducted to assess the impact of uncertainty in model inputs and assumptions on the study results. Results Vaccination with mRNA-1345 in high-risk adults aged 60-74 years and all adults aged [≥]75 years was projected to avert over 19,800 hospitalizations, 4,000 emergency department visits, 381,000 outpatient visits, 6,000 RSV-attributable deaths, and 212,000 antibiotic prescriptions compared with no vaccination over a 5-year period. The total incremental cost of {euro}1,143 million and the additional 47,477 QALYs gained resulted in an ICER of {euro}24,078, which was below the commonly referenced willingness to-pay range of {euro}33,000-40,000 per QALY gained. Sensitivity analyses confirmed robustness of the analysis results. Conclusions Vaccination with mRNA-1345 is a cost-effective strategy for the prevention of RSV in high-risk adults aged 60-74 years and all adults [≥]75 years in Italy and has the potential to provide substantial public health benefits.

Abstract Background: Cyprus has transitioned into a high-alert zone for mosquito-borne viruses. This necessitates a proactive assessment of its future physicians. Following the 2022 re-establishment of Aedes aegypti in Larnaca and Aedes albopictus in Limassol, Cyprus, the island is now biologically primed for local outbreaks of dengue, Zika, and chikungunya, alongside Culex-borne West Nile virus. The study assessed medical students' knowledge and risk perception. Methods: A cross-sectional online survey administered the validated MosquitoWise Health Belief Model instrument to undergraduate-entry and graduate-entry students at a university in Cyprus in mid-2026. Results: Of 1023 students, 119 responded (11.6%), with pre-clinical students overrepresented (p<0.001). Mean knowledge was 5.43/9, stronger on mosquito biology (72.5%) than virus knowledge (54.2%). Median severity was 6.00/7 against susceptibility 4.25/7. Knowledge differed by study stage (p<0.001), correlated with severity (rs = 0.399) but not susceptibility. Conclusions: The study establishes a critical baseline for pre-clinical medical students in Cyprus. Overall, participants performed better on mosquito biology when compared to mosquito-borne viruses and how they spread. Our findings highlight the value of integrating theoretical microbiology with clinical practice in medical education to enhance physicians' preparedness for the changing landscape of newly emerging infections in Cyprus and across Europe as a whole. Key Words: Arboviruses, Cross-Sectional Studies, Cyprus, Health Belief Model, Medical Students, Risk Perception.

Introduction Hepatitis E virus (HEV) in pregnancy is associated with high maternal and perinatal morbidity and mortality. The safety and efficacy of the recombinant protein HEV vaccine (HEV239, Hecolin) have been established in non-pregnant adult populations but there is limited information among pregnant women. This trial has two co-primary objectives: 1) to assess pregnancy-related and/or serious safety events among pregnant women between 14 and 34 weeks of gestation receiving two Hecolin doses four weeks apart compared to placebo recipients, and 2) to determine immune non-inferiority of pregnant recipients of two Hecolin doses four weeks apart compared to non-pregnant women. Methods and Analysis This is a multi-site, randomized, observer-blinded, placebo-controlled vaccine safety and immunogenicity trial in pregnant women and non-pregnant women of reproductive age in Karachi, Pakistan. A total of 2,358 healthy women will be enrolled, including 2,208 pregnant women between 14 and 34 weeks of gestation, who will be randomized in a 1:1 ratio (stratified by gestational age, 14-27 and 28-34 weeks) to receive either Hecolin or a normal saline placebo in two doses administered 1 month apart during pregnancy and a third dose administered postpartum, approximately 5 months after the second dose. A third arm of 150 non-pregnant women aged 16-45 years will receive Hecolin on 0, 1, and 6 months. The co-primary outcomes will be (i) the proportion of pregnancy-related AESIs and SAEs in pregnant participants from the first dose until the end of study follow-up, compared with placebo, and (ii) the geometric mean concentration (GMC) of anti-HEV IgG at four weeks after the second dose, comparing pregnant vaccine recipients with non-pregnant vaccine recipients (non-inferiority margin of 0.67 for the GMC ratio). Immunogenicity will be evaluated in a pre-specified subset of 300 participants receiving Hecolin, including 150 pregnant participants and 150 non-pregnant participants. Secondary outcomes will include maternal, neonatal, and infant safety outcomes, as well as immunogenicity according to the number of Hecolin doses received and the trimester of vaccination. Ethics and Dissemination The trial was approved by the National Bioethics Committee (NBC) of Pakistan (Reference number: 4-87/NBC-910), the institutional Ethics Review Committee (ERC) of the Aga Khan University (Reference number: 8298), and the Institutional Review Board (IRB) of the International Vaccine Institute (IVI) (Reference number: 2022-007). All participants will provide written informed consent in accordance with Good Clinical Practice. The results will be submitted to World Health Organization (WHO) Strategic Advisory Group of Experts in Immunization (SAGE), and disseminated through conference presentations, and peer-reviewed publications.

ObjectiveTo assess the knowledge, willingness and barriers to human papillomavirus (HPV) vaccination among caregivers of adolescent girls living with HIV in Sierra Leone. MethodsThis cross-sectional study examined HPV vaccine knowledge, willingness, and barriers among 249 caregivers of adolescent girls living with HIV in Sierra Leone. Data were collected through structured questionnaires at public tertiary hospitals and high-volume HIV clinics, and associations were assessed using chi-square tests, logistic regression, and Kruskal-Wallis analyses. ResultsOnly 32.1% (80/249) of caregivers had heard of HPV, with even fewer aware of its link to cervical cancer (24.4%, 60/246) or prevention methods of cervical cancer (31.9%, 79/248). Misconceptions were prevalent; 16.3% (36/221) erroneously linked oral contraceptives to cervical cancer, and 61.1% (44/72) of caregivers unwilling to vaccinate cited distrust in vaccine efficacy. While tertiary-educated caregivers exhibited the highest level of knowledge (45.5%, p < 0.001), their willingness to vaccinate (50%, 33/66) was comparable to that of less-educated groups, highlighting a knowledge-action gap. Structural barriers dominated, with 66.1% (154/233) citing unawareness of the vaccine and 10.3% (24/233) missing school-based vaccination days. Relationship dynamics significantly influenced willingness: extended family members showed the highest willingness (69.4%, p = 0.029), whereas grandparents were least willing (31%, 9/29). Although systemic gaps such as disrupted vaccination services, vaccine supplies and cold chain limited uptake, healthcare workers emerged as the most effective information source (rank sum = 889.5, p = 0.039). ConclusionThe study highlights the need for culturally tailored education to dispel myths and community-driven strategies engaging trusted actors like healthcare workers and extended families. This study justifies the need for integration of HPV vaccination and cervical cancer screening into HIV care services.

There is currently no clinical data for the effectiveness of the only licensed Ebola virus disease vaccine (Ervebo) against Bundibugyo virus disease. A number of studies have shown immune cross-reactivity with Bundibugyo virus after Ervebo vaccination. However, antibody recognition of Bundibugyo is around 2.8-fold lower than recognition of Ebola virus. Here, we aimed to infer how a 2.8-fold drop in immune recognition may affect Ervebo protection against Bundibugyo virus disease based on analysis of data on Ervebo immunogenicity and protection from Ebola virus disease. This work has three main components. Firstly, we analysed the timing of vaccine protection in the Ervebo pivotal ring vaccination clinical trial. Secondly, we performed a systematic review and meta-analysis of antibody responses to Ebola virus after Ervebo vaccination over time. Thirdly, we combined these data with previously reported data on the cross-reactivity to Bundibugyo virus to infer protection of Ervebo against Bundibugyo virus disease. We find that the clinical trial data for Ervebo supports vaccine protection beginning earlier than 10 days after vaccination. Secondly, binding antibody levels against Ebola virus on day 28 post vaccination (peak responses) were on average 12.9-fold (95% confidence interval, CI: 6.4 - 26.0) higher than on day 7, 6.3-fold (95% CI: 3.7 -10.8) higher than on day 10, and 2.5-fold (95% CI: 1.4 - 4.4) higher than on day 14 (neutralising antibodies showed similar results). Finally, we consider the scenarios where antibody levels to Ebola virus at day 7 or 10 are putative protective thresholds against Ebola virus disease, and we assume these thresholds also apply for Bundibugyo virus disease. Then, with a 2.8-fold reduction of responses to Bundibugyo compared to Ebola virus, we predict antibody responses to Bundibugyo virus after Ervebo vaccination are likely above these putative protective thresholds.

Endothelial cell dysfunction plays a key role in the pathogenesis of severe and critical COVID-19, leading to a multi-systemic inflammatory disease, and results from the direct interaction of the SARS-CoV-2 Spike proteins with endothelial cells. COVID-19 RNA vaccines encode a recombinant SARS-CoV-2 Spike protein which undergoes systemic biodistribution. No information is however so far available on the direct effects of COVID-19 RNA vaccines on human endothelial cells. In the present study, we exposed cultured human umbilical venous endothelial cells (HUVEC) to the COVID-19 RNA vaccine SpikevaxTM (Moderna, Inc.), and thereafter we measured the expression of the Spike protein, of the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor (TNF)-, of the adhesion molecules intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), as well as the attachment of human leukocytes to HUVEC layers. We also assessed the effects of SpikevaxTM on HUVEC viability. Exposure of HUVEC to the COVID-19 RNA vaccine SpikevaxTM resulted in effective cell transfection, and subsequent production of the Spike protein, which was expressed in the cells and secreted in the culture medium. Spike protein production was accompanied by increased gene expression of IL-6 and TNF- and of ICAM-1 and VCAM-1, as well as by increased attachment of leukocytes to HUVEC monolayers. Exposure to the COVID-19 RNA vaccine SpikevaxTM did not affect HUVEC viability. Our results provide a mechanistic explanation to post-COVID-19 RNA vaccination pathologies resulting from endothelial dysfunction, such as during atherosclerosis, autoimmune inflammation, and systemic inflammatory conditions.

Beyond Nominal Awareness: Mapping the Literacy to Action Chasm in Adolescent HPV Vaccination Across Sub-Himalayan India A School-Based Cross-Sectional Study in Bilaspur and Shimla Districts, Himachal Pradesh Dr. Debankur Chakraborty, Dr. Vanshika S. ABSTRACT Background: Cervical cancer is a major cause of death among Indian women, even though the HPV vaccine and routine screening can prevent it. Himachal Pradesh launched a state-funded HPV vaccination drive in early 2026. This study looks at what adolescent schoolgirls know about cervical cancer, whether they understand the vaccine, and what influences their choices. Methods: We surveyed 516 female students across seven schools (five government and two private) in Bilaspur and Shimla districts of Himachal Pradesh between May and July 2026 (93.8% response rate). The survey covered knowledge of cervical cancer, HPV, vaccine benefits, vaccination status, fears about infertility, and willingness to get vaccinated if advised by a doctor. Results: While 71.9% (371/516) of girls had heard of cervical cancer, only 47.3% (244/516) knew it begins in the cervix or lower uterus, 76.0% (392/516) knew no symptoms, and only 27.5% (142/516) recognized that it can be prevented (p<0.001). Similarly, 61.6% (318/516) had heard of the HPV vaccine, but only 41.9% (216/516) had heard of HPV itself (p<0.001), and only 50.0% (258/516) knew the vaccine prevents infection. Only 12.8% (66/516) had received at least one dose, and just two girls (0.4%) had finished all required doses. When asked if they would get vaccinated on a doctor's advice, 45.3% (234/516) wanted more information first, 34.1% (176/516) refused, and 20.5% (106/516) agreed. Three out of four girls (75.6%, 390/516) were concerned or uncertain about whether the vaccine causes infertility. Only 3.5% (18/516) had heard of a Pap smear. Conclusion: The findings demonstrate a pronounced decoupling between nominal awareness and actionable prevention literacy among adolescent schoolgirls in Himachal Pradesh. The predominant driver of vaccine hesitation was an unmet informational requirement rather than active ideological refusal. School-based immunization campaigns must incorporate structured, age-appropriate educational curriculum addressing the need of vaccination and infertility misconceptions prior to injection sessions.

Background: Tuberculosis (TB) remains a major public health challenge globally, with Pakistan ranking among the highest TB burden countries worldwide. Although several novel TB vaccine candidates for adolescents and adults are advancing through late-stage clinical trials, little is known about how these vaccines may be introduced in high-burden settings such as Pakistan. Understanding stakeholder perspectives is crucial for informing early implementation planning and policy development. Methods: We conducted an exploratory qualitative study using semi-structured in-depth interviews with key stakeholders involved in TB control, immunization, clinical care, and health policy in Pakistan. Participants were purposively selected from national and provincial TB programs, Expanded Programme on Immunization (EPI), clinical settings, and academia. Interviews were conducted in English or Urdu, audio-recorded, transcribed verbatim, and analyzed using reflexive thematic analysis following the Braun and Clarke framework. A hybrid deductive-inductive coding approach was used. Results: Ten stakeholders participated including one whose interview also served as a pilot test of the interview guide. Participants expressed strong support for the introduction of a new TB vaccine, driven largely by Pakistan's high TB burden and the limitations of current prevention strategies. However, support was based on the availability of strong evidence regarding vaccine safety, effectiveness, and feasibility. Key barriers to vaccine acceptability included low perceived risk of TB, misinformation, stigma, sociocultural influences, and limited public awareness. Stakeholders emphasized community engagement, trusted healthcare providers, and effective communication as critical enablers. Health system challenges included workforce shortages, cold chain limitations, and financing constraints. Household contacts of TB patients were consistently identified as the priority group followed by adolescents and people living with HIV. A phased implementation strategy was broadly preferred followed by gradual integration into existing health services. Conclusion: Stakeholders in Pakistan broadly support new TB vaccines for adolescents and adults. Successful implementation will require addressing sociocultural barriers, strengthening health system capacity, and developing context-specific delivery and prioritization strategies. Early stakeholder engagement and implementation planning are essential for meaningful public health impact in Pakistan.

Background Surveillance of adverse events following immunization (AEFI) and appropriate reporting are essential ingredients of an effective immunization programme. Despite increasing recognition by caregivers, the response to it remains a major problem, with the majority being inappropriate. This study is therefore intended to determine the prevalence, pattern, and determinants of caregivers response regarding AEFI in Nigerian hospitals. Methodology A descriptive cross-sectional study was conducted among 368 caregiver-infant pairs across 3 Nigerian hospitals, using semi-structured questionnaires to document sociodemographic characteristics and the prevalence, pattern, and determinants of caregivers response. Statistical analyses were performed using SPSS version 27. Predictors of AEFI and determinants of caregivers response were assessed using Pearsons chi-square and logistic regression. A p-value < 0.05 was considered statistically significant. Results The prevalence of AEFI was 71.7%, with inconsolable crying/irritability, fever, and swelling at the vaccination site as the leading cases. Infant age, weight, and gestational status at birth were predictors of AEFI occurrence. Only 8 (3.0%) caregivers presented at a healthcare facility when AEFI was noticed (appropriate response), while 360 (97.0%) did not (inappropriate). The relationship of the caregiver to the vaccinated infant (mother) was found to be a determinant of caregivers response to the occurrence of AEFI. Conclusion An increasing prevalence of AEFI that was not followed by an optimally appropriate response from caregivers has been demonstrated. This calls for more public enlightenment focusing on the need to report AEFI at healthcare facilities, as this will help in ensuring vaccine safety and improvement in the immunization programme.

Background: COVID-19 vaccination uptake is influenced by various sociodemographic and psychological factors. Previous studies have suggested that the relationship between personality traits and vaccination is context-dependent. However, this association has not been investigated in Japan, a unique sociocultural context characterized by historically low vaccine confidence but exceptionally high COVID-19 vaccine uptake. We examined the association between the Big Five personality traits and completion of the primary COVID-19 vaccination series, exploring potential gender-personality interactions. Methods: A web-based, cross-sectional survey was conducted among 7,210 Japanese adults (aged 20-85 years) in December 2021. Personality was assessed using the Japanese version of the Ten-Item Personality Inventory. Multivariable Poisson generalized estimating equations were used to calculate adjusted prevalence ratios (PRs) and assess gender-personality interactions. Results: Higher extraversion and lower openness were significantly associated with vaccination completion across genders. A significant gender-agreeableness interaction was observed: agreeableness (PR = 1.016, 95% CI: 1.008-1.024) was positively associated with vaccination completion among men but not women. A similar, though only marginally significant, interaction pattern was observed for neuroticism (PR = 1.011, 95% CI: 1.004-1.019 among men). Conclusions: Personality traits act as modest but meaningful, gender-specific psychological modifiers of vaccination behavior in Japan. Public health campaigns should transition from traditional "one-size-fits-all" messages to personality-tailored and gender-responsive communication strategies to optimize vaccine uptake and bolster psychological resilience in future pandemics.

BackgroundSince the COVID-19 pandemic, parental delays and refusals of well-established, safe, and effective childhood vaccinations have contributed to the resurgence of infectious diseases. This raises concerns that COVID-19 vaccine hesitancy may also extend to novel vaccines for children when introduced in the future. This study examined caregivers, who included healthcare workers (HCWs), perceptions of novel vaccinations for children ages 0-17 years old and intentions to vaccinate children and adolescents ages 12-17 years against COVID-19. MethodsWe conducted a secondary data analysis of a larger cross-sectional survey administered to parents/caregivers of children ages 0-17 years in Lusaka, Zambia, between 13 November and 15 December 2023. Vaccination intention for COVID-19 was specifically focused on caregivers of adolescents ages 12-17 years, following COVID-19 vaccination guidelines during the study. Descriptive statistics were used to explore demographic characteristics, vaccination history, and caregivers COVID-19 vaccination status, along with their childrens routine childhood vaccine histories and perceptions of COVID-19 and novel vaccinations. ResultsAmong 277 caregivers (66.8% women, median age: 35 years), 93.1% reported that their child had received all recommended routine childhood vaccinations. COVID-19 vaccine uptake was higher among HCWs (68.2% with [&ge;]2 doses) than among community members (40.8%) and having [&ge;]2 doses was associated with higher COVID-19 vaccine uptake among their adolescents ages 12-17 years. 58.0% of caregivers indicated that their 12-17 years old adolescents had received at least one COVID-19 vaccine dose. Overall intention to further vaccinate children against COVID-19, especially among those already unvaccinated, remained low, with 24.7% of caregivers reporting no intent to vaccinate their children. Protection from hospitalization and death from malaria, TB, HIV, pneumonia, influenza, and diarrheal diseases were the most cited reason (79.1%) for intention to vaccinate children with novel vaccines for these diseases. The most prominent reasons for reluctance towards future vaccines were the fear of potential side effects (45.5%) and insufficient knowledge about vaccination benefits and risks (31.8%). Caregivers most trusted the Ministry of Health (86.6%) and healthcare professionals (66.8%) as sources of vaccine information. ConclusionsWhile routine childhood vaccine uptake remained high, acceptance of COVID-19 and future novel vaccines for children was lower and was influenced by caregivers own vaccination status. Targeted and transparent communication through trusted sources such as the Ministry of Health and healthcare professionals may be critical for addressing safety concerns and strengthening confidence in novel childhood vaccines.

Importance: Nirsevimab, a monoclonal antibody against RSV, was implemented in France in September 2023. Recently, rare resistance-associated substitutions were described in RSV but the effectiveness according to lineages remains unclear. Objective: We aimed to estimate the effectiveness of nirsevimab against hospitalization for RSV bronchiolitis according to RSV lineages. Design: We conducted a multicenter test-negative case-control study from October 15, 2023 to March 15, 2025. Setting: This study was based on data from three national multicentric prospective studies. The 12 participating centers were secondary or tertiary hospital with a pediatric department located in France. Participants: We included all children younger than 12 months who were hospitalized for RSV bronchiolitis in one of the participating centers in France during the two first RSV epidemic seasons following the implementation of nirsevimab (from October 15, 2023 to February 29, 2024, and from October 10, 2024 to March 15, 2025). Main outcomes and measures: The main outcome of the study was the RSV test result of bronchiolitis cases. RSV whole-genome sequencing was performed using a tiled amplicon approach covering the complete viral genome, as previously described in the POLYRES studies. We estimated the effectiveness of nirsevimab by a multivariable logistic regression model adjusted for potential confounders. We estimated the adjusted risk of immunization failure for each lineage by calculating relative odds ratio to a reference lineage. A range of sensitivity analyses were conducted. Results: We included 3019 infants with bronchiolitis among which 2273 had a positive RSV test (case patients) and 746 had a negative RSV test (control patients). Overall, 373/2273 (16.4%) case patients were immunized by nirsevimab versus 423/746 (56.7%) control patients. The adjusted effectiveness of nirsevimab against hospitalization for bronchiolitis was 88.4% (95% CI, 84.5-91.4) with RSV-B and 79.4% (95% CI, 73.7-83.8) with RSV-A. The risk of immunization failure was 3.2-fold (95% CI 1.8-5.7) higher for lineages derived from A.D.3 than for lineages derived from B.D.4.1. Conclusion and relevance: In this multicentric case-control study, we observed that nirsevimab effectiveness was variable across RSV lineages, with a lower effectiveness against A.D.3 lineages compare to others. Further surveillance is needed to confirm these findings and assess their implication on RSV lineages epidemiology as nirsevimab use expands.

Background: Nigeria introduced single-dose HPV vaccination for girls aged 9-14 in 2023, reaching approximately 60% aggregate coverage by 2025. While an important achievement, this remains short of the 90% coverage called for under the WHO's 90-70-90 cervical cancer elimination targets, and further scale-up depends on reaching out-of-school girls. In this study we used a model of HPV transmission in Nigeria to quantify the residual cervical cancer burden under continued adolescent delivery, assess how additional screening scale-up and equity assumptions modify it, and identify the effective coverage requirements for an infant HPV vaccination program to be non-inferior to the existing adolescent strategy. Methods: We used HPVsim, an agent-based microsimulation calibrated to Nigerian sexual behavior, HPV prevalence, and cervical cancer incidence, to project new cervical cancer cases and age-standardized incidence over 2025-2100 under scenarios which vary vaccination delivery mode (status-quo adolescent, WHO 90-70-90 adolescent scale-up, and 60/75/90% infant delivery), screening coverage (opportunistic 15% vs. scaled 70% aggregate), and the degree to which primary school completion correlated with vaccination (odds ratio 1 vs. 5) and with screening (odds ratio 1 vs. 3). Infant delivery scenarios were run at hypothetical effective-vaccine-efficacy-at-exposure values of 50%, 70%, and 95% - scenario inputs bracketing the plausible waning range, not evidence-based estimates of infant vaccine performance (no HPV vaccine trial has enrolled anyone below age 10). Each scenario was run at 50 replicates (10 calibration draws, 5 seeds); reported outcomes are the median across replicates and uncertainty ranges are interquartile (25th-75th percentile). Results: Continuation of Nigeria's current adolescent program is projected to avert 1.82 million cervical cancer cases (IQR 1.65-1.90 million; 95% UI 1.39-2.02 million) over 2025-2100 (a 53% reduction relative to no vaccination, IQR 51-55%; 95% UI 46-58%), with age-standardized incidence falling from 19.7 to 7.8 per 100,000 by 2100. However, 82% of the near-term (2025-2075) burden is projected to fall on the pre-2015 birth cohort, i.e. women already beyond the vaccination target age, leaving approximately 945,000 residual cases (IQR 905K-1.00M; 95% UI 835K-1.14M) in this cohort. Scaling up screening to WHO targets was estimated to avert a further ~387K cases (IQR 331-424K; 95% UI 269-515K), roughly 25% of the residual burden; results were about 6-8% better if the scale-up instead reached all women equitably regardless of education. Under a hypothetical scenario of infant vaccination at 90% coverage and 95% effective vaccine efficacy at exposure (matching adolescent-age performance), outcomes were comparable to full WHO adolescent scale-up (49% vs. 54% reduction in vaccine-targetable cohort cancers), but under a hypothetical 50% effective efficacy at Nigeria's DTP3-anchored 62% coverage the strategy averted only a fraction of these cancers. Conclusions: The near-term cervical cancer burden in Nigeria is dominated by cohorts vaccination cannot reach; scaling screening for them is the more consequential lever over the coming three decades and rests on established evidence. Findings on infant HPV delivery are exploratory and hypothesis-generating: they depend on three unverified empirical prerequisites - infant HPV vaccine immunogenicity in the first months of life, durability of protection across the ~15-25-year interval to peak HPV exposure, and coverage achievable through Nigeria's routine childhood immunization platform - and should not be read as a basis for any policy recommendation contingent on infant HPV delivery until those prerequisites are established.

Cervical cancer is a leading cause of cancer death among women in Zambia, and vaccination of girls aged 9-14 years against human papillomavirus (HPV) is the principal primary prevention strategy. Because the vaccine is given to minors, uptake depends on parental consent, which is shaped by how parents perceive the vaccine. In Kabompo, a rural, ethnically diverse district of North-Western Province, only 59% of eligible girls had been vaccinated by 2024, well below the global target, yet no qualitative evidence existed on how parents in such settings understand and decide about the vaccine. We conducted a descriptive phenomenological study at Kabompo Hospital Affiliated Health Centre between June and August 2025. Twenty parents and legal guardians of girls aged 9-14 years were purposively selected using maximum variation sampling and interviewed in depth in English or Luvale. Interviews were audio-recorded, transcribed verbatim and analysed using Colaizzi's seven-step method with QDA Miner Lite. Five themes were generated: knowledge and awareness of HPV and its vaccine; perceptions of safety and efficacy; sociocultural and religious influences; the role of health workers; and barriers to access. Most parents knew the vaccine prevents cervical cancer, but few could explain how HPV causes cancer or state the schedule, and several first learned about the vaccine at the point of service. Fear of infertility was the most prominent concern, alongside unease that the vaccine was too new. Religious framings of divine protection, preference for herbal remedies, and concern that vaccination condones early sexual activity shaped decisions. Health workers were the most trusted source of information and were often decisive. Distance, transport costs, fear of injections and incomplete dosing limited uptake. Stated acceptability was high but did not consistently translate into vaccination, indicating an intention-behaviour gap that information campaigns alone are unlikely to close.

Aims: To estimate the preventable pneumococcal disease burden by 21-valent pneumococcal conjugate vaccine (PCV21) compared to PCV20 for the national immunization program for adults aged 65 years or older in Japan. Methods: Serotype distribution among isolates and the annual incidence of invasive pneumococcal disease (IPD) in adults were monitored. The numbers of IPD or pneumococcal community-acquired pneumonia (pCAP) cases preventable by immunization with PCV20 or PCV21 were estimated according to reported vaccine efficacy and duration of protection in older adults. Data from our nationwide study of adult IPD surveillance and a multicenter study of pCAP were used. Results: The mean annual incidence of adult patients with IPD caused by all serotypes among adults aged [&ge;]65 years, which declined during the COVID-19 pandemic period, recovered to 89% of the pre-pandemic level in 2025. During 2023-2025, the proportion of PCV20-non-PCV21 serotypes was 8.5% for adults aged [&ge;]65 years. At the current vaccination coverage rate of 40%, the numbers of preventable IPD cases (per person per year) by PCV20 and PCV21 were 36 and 53, respectively. The preventable numbers of pCAP cases by PCV20 and PCV21 were 2,821 and 4,765, respectively. The estimated number of preventable pCAP cases was approximately 80-90 times higher than that of preventable IPD cases. Conclusion: Our data indicate that PCV21 could prevent 1.5-1.7 times as many pneumococcal disease cases as PCV20 among adults aged [&ge;] 65 years in Japan. However, PCV20 should be considered if the incidence of adult IPD cases caused by PCV20-non-PCV21 serotypes increases.

Chronic hepatitis B virus (HBV) infection remains a major global health challenge because current antiviral therapies rarely achieve complete viral clearance. We evaluated the antiviral activity of a newly developed monoclonal antibody, 7-4G mAb, directed against the hepatitis B surface antigen (HBsAg). The antibody showed specific binding to the p27 component of HBsAg and efficiently removed HBV-related particles from patient serum in vitro. Significant HBV neutralizing activity of 7-4G mAb was observed in primary human hepatocytes and in humanized mouse models. In persistently HBV-infected PXB mice, a single administration of 7-4G mAb, either alone or in combination with another monoclonal antibody, reduced serum HBsAg levels and HBV DNA levels by two orders magnitude for two weeks after the treatment. In half of the treated mice, suppression of both viral markers was maintained through the study period, whereas rebound occurred within three to four weeks in the remaining animals. In addition, 7-4G mAb enhanced the HBV DNA-lowering effect of entecavir, a known anti-HBV drug. These findings support the further development of 7-4G mAb as part of an innovative HBV treatment strategy, addressing limitations of existing therapies and advancing toward a more effective HBV management solution.

There are currently no approved vaccines or medical countermeasures for use in prevention or treatment of Bundibugyo virus disease. A critical question is whether the existing vaccines approved for use against Ebola virus disease could provide sufficient cross-reactivity and cross-protection against Bundibugyo virus disease. We performed a systematic review and meta-analysis of published studies of antibody cross-reactivity to Bundibugyo virus (BDBV) after vaccination with previously approved Ebola vaccines (Ervebo or Zabdeno/Mvabea). We find on average a 2.8-fold (95% predictive interval, PI: 2.6-3.0) drop in binding (n = 8 observations from 4 studies) and 3.1-fold drop (95% PI: 2.0-4.8) in neutralization (n = 2 observations from 1 study) between Ebola virus and BDBV antigens after Ervebo vaccination, which appears maintained over time after vaccination. Very limited data on cross reactivity after Zabdeno/Mvabea vaccination suggests a higher drop in recognition of BDBV (39.7-fold, 95% PI: 24.8-63.8; n = 3 observations from 2 studies). In addition to analysis of antibody recognition in humans, we also investigated evidence for vaccine protection from BDBV challenge in animal models after Ervebo or other recombinant vesicular stomatitis virus (rVSV) based vaccines containing only Ebola antigen. A single study in NHP showed non-significant vaccine protection from BDBV challenge, while a study in ferrets showed significant protection after both one and two doses. The available data demonstrate immune cross-reactivity and some evidence for protection in animals, although further clinical and pre-clinical data is urgently needed to inform decisions on the use of Ervebo to protect against Bundibugyo virus disease.

Background Shigella remains an important cause of childhood diarrhoeal disease and a growing contributor to antimicrobial resistance in low- and middle-income countries (LMICs). Several Shigella vaccines are in development, yet little is known about community and stakeholder perspectives regarding the introduction of future Shigella vaccines in Pakistan. We explored perceptions related to diarrhoeal disease, vaccine acceptance, and health system readiness to inform the future introduction of a Shigella vaccine. Methods We conducted a qualitative study in Karachi, Pakistan, between August 2024 and March 2025. Data collection comprised six focus group discussions (FGDs) with caregivers of children under five years of age, and 16 in-depth interviews (IDIs) with key stakeholders including healthcare providers, Expanded Programme on Immunization (EPI) officials, policymakers, technical experts, school administrators, and community and religious leaders. Semi-structured interview guides informed by the Health Belief Model. Audio-recorded interviews were transcribed verbatim, translated into English, and analyzed thematically using both deductive approaches and inductive approaches. Results Four interconnected themes emerged from the data: perceptions of diarrhoeal disease and Shigella; factors shaping acceptance of a future Shigella vaccine; evidence and health-system readiness for vaccine introduction; and vaccine attributes, adoption, and sustainability. Although childhood diarrhoeal disease was widely recognized, awareness of Shigella as a specific pathogen was limited. Participants expressed conditional acceptance of a future Shigella vaccine, influenced by trust, perceived safety, and recommendations from healthcare providers and community leaders. Stakeholders emphasized the need for stronger local evidence on disease burden and cost-effectiveness to support vaccine prioritization, while identifying Pakistan's existing immunization infrastructure as a strength for implementation. Some participants favoured combination vaccines to reduce injections and simplify vaccine delivery, while others emphasized that vaccination should complement continued improvements in water, sanitation, and hygiene. Conclusion Knowledge of Shigella and its vaccine was limited, but stakeholders supported future vaccine introduction if informed by local evidence, policy commitment, and program integration.