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PubMed2026

Safety and immunogenicity of an mRNA COVID-19 vaccine administered to adults: A phase 2, randomized, active-controlled trial.

We conducted a phase 2, randomized, active-controlled, observer-blind study (NCT05960097) among healthy adults ≥18 y of age who completed a primary COVID-19 mRNA vaccination series, with or without a booster, ≥3 months earlier. Participants were randomized (1:1:1:1:1) to either receive an investigational bivalent mRNA COVID-19 vaccine encoding ancestral D614G and Omicron BA.4-5 spike proteins (CV0701 mRNA vaccine) at one of three dose levels, an investigational monovalent mRNA COVID-19 vaccine encoding the Omicron BA.4-5 spike protein (CV0601 mRNA vaccine), or a licensed Original Wuhan/Omicron BA.4-5 bivalent mRNA COVID-19 vaccine. The primary objectives were to evaluate reactogenicity, safety and immunogenicity post-vaccination. Secondary and tertiary objectives were to further evaluate humoral and cell-mediated immunity post-vaccination. In total, 425 participants were vaccinated and 381 were included in the Day 29 per-protocol immunogenicity analysis. Most solicited events were mild to moderate. No vaccine-related serious adverse events or myocarditis/pericarditis cases were reported. For the CV0701 mRNA vaccine, a dose-dependent increase in Day 29 neutralizing titers against ancestral D614G and Omicron BA.4-5 was observed. Neutralizing titers against ancestral D614G and Omicron BA.4-5 declined by Days 91 and 181, but remained above baseline. Similar immune responses were observed for the CV0601 mRNA vaccine. At Day 8, CD4+ T cells (Th1 profile) increased in all study groups and CD8+ T cells increased in all study groups, except the lowest CV0701 dose group. The CV0701 and CV0601 mRNA vaccines elicited robust humoral and cellular immunity with an acceptable safety profile, comparable to a licensed, bivalent mRNA vaccine. Clinical Trial Registration EU CT number: 2023-504596-25-00 ClinicalTrials.gov: NCT05960097.

Humans↗

PubMed2026

Approaches to observational study designs and analytical options to evaluate the safety of multi-dose vaccines: a systematic review.

INTRODUCTION: Observational studies require careful considerations when evaluating the safety of multidose vaccines. We reviewed design and analytical approaches in observational studies evaluating the safety of multidose vaccines in the post-licensure phase. METHODS: EMBASE, MEDLINE, Web of Science, and Scopus (2018-2022) were searched for hypothesis-testing studies evaluating the safety of multidose vaccines. Key features from frequently used designs were extracted. RESULTS: Among 123 eligible studies, cohort (46%) and self-controlled case series (SCCS)/self-controlled risk interval (SCRI) (40%) followed by case-control (12%) were the most common designs, and 15% of studies used multiple designs. Among cohort studies evaluating multiple doses, vaccination date (36%) and cohort entry with time-updated exposure status (32%) were frequent approaches used to define time zero. Twenty-eight percent of cohort studies did not report time zero; all but one evaluated COVID-19 vaccine effect on post-delivery and fertility-related outcomes. For SCCS/SCRI, 64% of studies accounted for event-dependent exposures, mainly by including pre-exposure periods (53%) and modified SCCS model (48%), while 20% employed multiple correction strategies. Among studies using multiple designs, 68% reached consistent conclusions. CONCLUSIONS: SCCS/SCRI and cohort designs dominate multidose vaccine safety studies. Clear reporting on time zero in pregnancy and fertility-related cohort studies, and on addressing event-dependent exposures in SCCS/SCRI studies is needed, along with guidance on interpreting results from multiple designs.

Humans↗

PubMed2026

Stroke risk following BNT162b2 vaccination: a systematic review and meta-analysis of self-controlled case series studies.

INTRODUCTION: Whether BNT162b2 (Pfizer-BioNTech) vaccination increases stroke risk remains a public health concern. This is the first meta-analysis to synthesize self-controlled case series (SCCS)-derived stroke risk estimates specifically for BNT162b2 vaccination. METHODS: PubMed and Embase were searched from inception through 9 May 2026, following PRISMA 2020 guidelines. Eight eligible SCCS studies were pooled using a random-effects model with restricted maximum likelihood (REML) estimation and the Knapp-Hartung adjustment. RESULTS: Eight studies across six countries encompassing several million vaccinated individuals were included. The pooled incidence rate ratio (IRR) was 0.967 (95% CI 0.892-1.049; I2 = 69.2%), indicating no statistically significant increase in stroke risk. Subgroup analyses showed no evidence of effect modification across continent, risk-window length, dose category, SCCS variant, or age group. CONCLUSIONS: These findings provide no evidence of increased short-term stroke risk following BNT162b2 vaccination at the population level. The observed heterogeneity appeared to be partly driven by methodological differences rather than true biological variation in vaccine effect.

Humans↗

PubMed2026

Cognitive-behavioral therapy for post COVID-19 condition: A pilot randomized controlled trial.

BACKGROUND: The post COVID-19 condition (PCC) is a disabling condition with urgent need for effective treatments. This pilot randomized controlled trial examined the feasibility and efficacy of a cognitive-behavioral therapy (CBT) for PCC in a parallel-group design. METHODS: N = 53 individuals with PCC were randomized to CBT (n = 27) or 16-week wait-list control (WLC) condition (n = 26). One participant allocated to WLC was excluded after randomization, resulting in an intention-to-treat (ITT) sample of N = 52 participants (CBT: n = 27, age: M = 48.59, SD = 11.52, 77.8% female; WLC: n = 25, Age: M = 48.44, SD = 9.81, 60% female). CBT comprised eight group and five individual sessions addressing cognitive and behavioral factors of symptom maintenance (treatment duration if completed: M = 14 weeks, SD = 1 week). Primary outcomes included fatigue (FSS), overall somatic symptom burden (PHQ-15), and respiratory and cardiovascular symptoms (SBQ™-LC "Breathing" and "Circulation"), assessed at pre-, post-assessment, and follow-up. RESULTS: Participants receiving CBT showed a significant medium-sized reduction in fatigue directly after treatment compared to the WLC condition (d = -0.58, p = .045), whereas the WLC group showed a significant increase in overall somatic symptoms (d = 0.60, p = .027). Results for respiratory symptoms were mixed, showing inconsistent patterns across analyses. Retrospectively assessed feasibility and treatment satisfaction were good, with few adverse effects reported. CONCLUSIONS: This pilot trial suggests the feasibility and preliminary efficacy of CBT for PCC. Larger RCTs with active control groups should confirm these findings.

Humans↗

PubMed2026

Psychological interventions to improve maternal mental health and resilience during pregnancy in the COVID-19 pandemic: a systematic review.

BACKGROUND: During the COVID-19 pandemic, pregnant women experienced increased psychological distress, while access to routine mental health care was often disrupted. Psychological interventions may provide an effective strategy to support maternal mental health under these circumstances. OBJECTIVE: This systematic review aimed to provide an overview of psychological interventions for pregnant women during the COVID-19 pandemic and to evaluate their effectiveness in reducing distress and enhancing resilience. METHODS: A systematic search of four databases was conducted up to 3 September 2025. Randomised and non-randomised studies evaluating psychological interventions during pregnancy were included. RESULTS: Sixteen studies met the inclusion criteria. Interventions included cognitive behavioural therapy, mindfulness-based interventions, psychoeducation, and other psychological approaches delivered through individual, group, digital, or hybrid formats. Most studies reported reductions in depression, anxiety, or stress, and some found improvements in resilience-related factors. However, the methodological quality was modest; with heterogeneous outcome measures and limited follow-up. CONCLUSIONS: Overall, psychological interventions adapted for digital or hybrid delivery show promise for improving maternal emotional well-being in times of crises. The findings suggest that accessible and scalable psychological interventions may support maternal mental health during crisis situations when routine care is disrupted. Future research should prioritize larger, methodologically rigorous trials with standardized outcomes, and longer follow-up periods.

Humans↗

PubMed2025

The impact of the COVID-19 pandemic on osteoporotic fractures: a systematic review and meta-analysis.

BACKGROUND: Recent reports suggest that the COVID-19 pandemic and associated lockdowns may have influenced the epidemiology of osteoporotic fractures, but results vary across regions and fracture types. The aim of this study was to provide evidence-based insights into the impact of the pandemic on osteoporotic fracture incidence. METHODS: We searched four databases (PubMed, Embase, Cochrane Library, and Web of Science) up to August 2025 for observational or retrospective studies comparing osteoporotic fracture incidence during the COVID-19 pandemic (2020) with the pre-pandemic period (2019). The primary outcome of interest was the change in fracture incidence, analysed using risk ratios (RR) with 95% confidence intervals (CI) in Review Manager 5.4. Subgroup analyses were performed by sex, geographic region, and fracture type. RESULTS: Nine studies meeting the inclusion criteria were analysed. Overall, "all types" of osteoporotic fractures showed a significant decrease during the pandemic (RR = 0.85, 95% CI 0.80-0.91, p < 0.0001). Specifically, forearm fractures decreased significantly (RR = 0.87, 95% CI 0.79-0.96, p = 0.002). However, for the most clinically significant fractures, no statistically significant global change was found for hip fractures (RR = 0.93, 95% CI 0.76-1.15, p = 0.14) or vertebral fractures (RR = 1.35, 95% CI 0.85-2.15, p = 0.20). In regional subgroup analysis, hip fracture incidence decreased significantly in South America (RR = 0.79, p = 0.0004) and in both males and females, but no significant change was observed in Europe (RR = 0.92, 95% CI 0.81-1.04, p = 0.17). CONCLUSION: During the COVID-19 pandemic, there was a decrease in the incidence of minor fractures, such as those of the forearm, likely due to reduced outdoor activity. However, the incidence of major osteoporotic fractures (hip and vertebral) remained stable globally, with significant reductions observed only in specific regions like South America.

Humans↗

PubMed2026

Evaluation of one-step amplicon-based targeted enrichment for SARS-CoV-2 whole-genome sequencing using the Midnight amplicon scheme.

Genomic surveillance proved invaluable during the COVID-19 pandemic for tracking SARS-CoV-2 variants and guiding outbreak responses, underscoring the ongoing need to reduce whole-genome sequencing (WGS) costs and improve workflow efficiency to ensure accessibility in resource limited settings. Here, we evaluated a one-step reverse transcription polymerase chain reaction (RT-PCR) approach using the Midnight V2 primer scheme for targeted amplification of the SARS-CoV-2 genome, assessed its compatibility with Illumina sequencing, and compared its performance to a well-established two-step method. Initially, we determined optimal RT-PCR reaction conditions using the Midnight V2 primer panel for the one-step RT-PCR kit and scaled reaction volumes for both RT-PCR and library preparation. Clinical specimens (n = 53) that had undergone routine WGS for surveillance purposes using the established two-step RT-PCR method were compared using the one-step RT-PCR assay. For samples with genome completeness greater than 70%, both methods gave comparable results with similar sequence coverage and 100% concordance for lineage assignment. Further investigation revealed a higher percentage of reads aligning to the SARS-CoV-2 genome with a greater depth of coverage using the one-step method compared to the two-step method. Finally, analysis of scaled one-step and library reaction volumes revealed significant cost savings for samples undergoing WGS. Overall, the results presented here verify the accuracy and reproducibility of one-step targeted amplification and offer an efficient and cost-effective workflow for routine SARS-CoV-2 genomic surveillance.

Humans↗

PubMed2026

A pragmatic randomized controlled trial of self-directed online writing interventions for posttraumatic stress symptoms in a real-world digital setting.

Background: Public health and other large-scale crises, such as the COVID-19 pandemic, have intensified the global mental health burden, creating unprecedented demand for accessible interventions for posttraumatic stress symptoms (PTSS).Objective: We evaluated the feasibility and effectiveness of two self-directed online writing interventions embedded within China's WeChat ecosystem during the COVID-19 pandemic through a pragmatic randomised controlled trial.Methods: Between December 2021 and August 2022, 1,526 adults were screened for PTSS via a Tencent Medinfo Mini-Program. Eligible participants (n = 211) were randomised to Guided Narrative Technique-Writing (GNT-W, n = 100) or Expressive Writing (EW, n = 111). Both interventions comprised three self-directed daily writing sessions delivered entirely online without human support. Primary outcome was PTSD symptom severity (PTSD Checklist-Short), assessed at baseline, post-intervention, 2-week, and 1-month follow-ups.Results: While initial engagement followed typical digital health patterns (64.5% overall attrition), participants who initiated treatment showed strong adherence (77% completion). Both interventions were associated with significant within-group reductions in PTSS severity (GNT-W: b = -0.43, p = .023, d = -0.43; EW: b = -0.60, p = .001, d = -0.58), with no significant between-group difference (group × time: b = 0.18, p = .48). GNT-W did not confer additional benefit over EW protocol on PTSS severity.Conclusions: Both self-directed writing interventions were associated with within-group reductions in PTSS; without an inactive control condition, however, these changes cannot be firmly attributed to the interventions. GNT-W showed no advantage over the simpler EW protocol. These findings offer preliminary support for embedding scalable, low-barrier writing interventions in widely used digital platforms.Chinese Clinical Trial Registry: ChiCTR2000034836.

Humans↗

PubMed2026

Do vaccinated cases transmit measles? A systematic review and meta-analysis.

INTRODUCTION: We reviewed evidence on whether vaccinated individuals can transmit measles and conducted a meta-analysis to understand transmission characteristics. METHODS: We searched and extracted data from peer-reviewed and gray literature and included studies reporting measles transmission events from vaccinated individuals. We meta-analyzed the data to calculate the median number of transmissions from vaccinated cases by measles burden, number of doses, and time since first and last dose. RESULTS: We identified 11,911 peer-reviewed and 22 gray literature records and included 33 articles in our review. Seventy individuals who had received 1 or more doses of measles-containing vaccine transmitted measles virus, resulting in 237 secondary cases. Vaccinated transmitters in eliminated areas were older (median age of 19 years (IQR: 3, 21)) than those in non-eliminated areas (median age 16 years; IQR 13, 18) (p = 0.12). Additionally, 91% (30/33) of studies provided data on subsequent transmission generations, leading to 812 measles cases traced back to vaccinated individuals, with a median of 4 (IQR: 1, 10) cases per vaccinated transmitter. CONCLUSION: Measles transmissions from vaccinated cases, although relatively uncommon, must be considered in public health investigations, as such transmissions can contribute to outbreaks.

Adolescent↗

PubMed2026

Vaccine preferences and their role for vaccine confidence and uptake: a meta-ethnography.

Vaccine confidence and uptake are influenced by individuals' preferences regarding vaccine composition, quality, or administration pathways. However, literature synthesizing available qualitative insights into individuals' vaccine preferences remains limited. We therefore conducted a meta-ethnographic systematic review of the qualitative literature on vaccine preferences to identify opportunities for enhancing vaccine confidence and uptake. We implemented a comprehensive search strategy and screened 5,528 studies across seven research databases published between 2001 and 2023. We identified and synthesized 97 qualitative articles to delineate factors influencing consumers' vaccine preferences. Our findings revealed four primary domains shaping individuals' vaccine preferences: Product, Place, Price, and Promotion. First, individuals' preferences for vaccines often hinge on perceived quality and safety of the product itself, which can, for example, be associated with vaccine brand or origin, especially in the case of novel vaccines. Second, people prioritize convenience in terms of vaccination sites and delivery methods (wanting vaccinations offered at their doorstep or in local peripheral clinics); evidence regarding preferred groups to administer the vaccines was mixed. Third, the price of vaccines and the secondary costs associated with vaccination played a role in uptake considerations. Finally, both the sources of information (such as healthcare workers, community volunteers, and religious authorities) and the methods of promoting vaccine information (including face-to-face consultations during clinic visits and the distribution of leaflets or banners), emerged as crucial factors shaping decision-making processes. Overall findings highlight the importance of addressing multifaceted preferences to enhance vaccine confidence and uptake. By understanding individuals' vaccine preferences, strategic recommendations can be developed to optimize vaccination programs and ensure acceptability and utilization.

Humans↗

PubMed2026

Population-level impact of HPV vaccination: a global systematic review of ecological, cross-sectional, and cohort studies.

BACKGROUND: Human papillomavirus (HPV) causes approximately 4.5% of cancers globally, with the highest burden in low- and middle-income countries (LMICs). Since their introduction in 2006, HPV vaccination programs have led to substantial declines in HPV-related outcomes, although impact varies across settings. RESEARCH DESIGN AND METHODS: We conducted a systematic review to evaluate the population-level impact of HPV vaccination on HPV infection, cervical intraepithelial neoplasia grade 2 or higher (CIN2+), genital warts, invasive cervical cancer (ICC), and oropharyngeal cancer (OPC), and examined the influence of coverage, age at initiation, and vaccine type. The review followed PRISMA 2020. RESULTS: Of 13,549 records screened, 63 were included: 9 assessed HPV infection, 24 on CIN2+, 25 on genital warts, and 7 on ICC. Greatest reductions were observed in settings with at least 70% coverage and early vaccination prior to sexual debut, typically achieved through school-based programs. Reported declines ranged from 58-100% for HPV infection, 30-88% for CIN2+, 60-90% for genital warts, and 70-88% for ICC. CONCLUSIONS: HPV vaccination offers strong protection, especially when delivered early and at high coverage within schools. Expanding access and prioritizing underserved populations are essential to achieving global cancer prevention goals. Limitations include heterogeneity across designs, outcome definitions, and follow-up.

Humans↗

PubMed2026

Ethiopia missed opportunities for vaccination study: Cluster-randomized evaluation of 5-dose measles vaccine vials and a flexible open-vial policy, 2021-2022.

INTRODUCTION: In 2024, an estimated 95,000 people died from measles globally, largely from suboptimal coverage with the measles-containing vaccine (MCV). Health workers may defer vaccinating eligible children to avoid wasting doses from 10-dose MCV vials, which must be discarded six hours after opening. These missed opportunities for vaccination (MOV) reduce coverage and timeliness. Ethiopia, which provides MCV at 9 and 15 months, considered switching to 5-dose vials. METHODS: We conducted a 15-month, randomized controlled trial with a nested cross-sectional design in Ethiopia. Sixty woredas were randomized to: (1) policy-only, instructing health workers to open 10-dose vials for any number of eligible children, with additional stock for increased wastage; (2) 5-dose switch, combining this policy with replacement of 10-dose by 5-dose vials; or (3) control (routine 10-dose practice). Household and health-facility surveys at baseline and endline assessed effects on first-dose (MCV1) and second-dose (MCV2) coverage, MCV1 timeliness, and wastage. Generalized estimating equation models estimated net intervention effects versus control. We also estimated the government cost of a nationwide 5-dose switch. RESULTS: MCV1 coverage was similar between policy-only and control (adjusted risk difference [ARD] = -1%, 95%CI: -17%, 15%), with no significant differences in MCV1 timeliness or MCV2 coverage. In the 5-dose switch group, MCV1 coverage changed little (ARD = 1%, 95%CI: -17%, 18%), but timely MCV1 at 9 months (ARD = 18%, 95%CI: 7%, 28%) and MCV2 coverage (ARD = 17%, 95%CI: 1%, 34%) rose significantly, and wastage fell (ARD = -7%, 95%CI: -14%, -1%). By endline, 29% of 5-dose health workers opened vials ≥10 times monthly (none in control); caregivers in both intervention groups reported 11% fewer measles-related MOVs. A nationwide 5-dose switch was estimated to save 17% in procurement cost per fully vaccinated (two-dose) child. CONCLUSIONS: The combined 5-dose intervention improved MCV1 timeliness and MCV2 coverage and reduced wastage, addressing a key operational barrier and potentially supporting measles elimination in Ethiopia.

Humans↗

PubMed2025

Exploring determinants of vaccine hesitancy among healthcare professionals: a systematic literature review.

INTRODUCTION: This systematic review aims to assess determinants of vaccine hesitancy (VH) among healthcare professionals, to identify knowledge gaps and inform targeted training programs. RESEARCH DESIGN AND METHODS: A systematic search of PubMed and Scopus was conducted in February 2024. PRISMA criteria were applied, and methodological quality was assessed using a cross-sectional study evaluation tool. Studies addressing HCWs' VH determinants, including knowledge, attitudes, communication, and organizational factors, were included. RESULTS: Out of 1394 records, 221 articles were included. Reported prevalence of VH among HCWs varied across studies, reflecting differences in professional roles, settings, and vaccines studied. Key determinants included gaps in knowledge, personal beliefs, organizational barriers, and communication skills. The review highlights the importance of evidence-based information, continuing education, and effective communication in addressing VH among HCWs. CONCLUSIONS: Educational and organizational interventions are essential to improve HCWs' knowledge, attitudes, and practices regarding vaccination. Strengthening vaccine education, fostering effective communication, and addressing organizational challenges can reduce hesitancy and support HCWs in promoting vaccination among patients. Future initiatives should consider the diversity of educational settings, professional roles, and training requirements across healthcare systems.

Humans↗

PubMed2026

Safety of a quadrivalent meningococcal conjugate vaccine (MenACYW-TT) administered concomitantly with routine pediatric vaccines in healthy infants and toddlers in USA and Puerto Rico: Results from a Phase III, randomized, active-controlled study.

MenACYW-TT, a quadrivalent meningococcal tetanus toxoid-conjugate vaccine, is approved for prevention of invasive meningococcal disease in infants ≥ 6 weeks of age in the USA. This Phase III study (NCT03673462; September 17, 2018 - March 16, 2023) evaluated the safety of MenACYW-TT compared with a licensed quadrivalent meningococcal oligosaccharide diphtheria CRM197-conjugate vaccine (MenACWY-CRM) when administered concomitantly with routine pediatric vaccines in healthy infants and toddlers in a four-dose series (3+1 schedule). Participants were randomized 3:1 to receive MenACYW-TT (Group 1; n = 2080) or MenACWY-CRM (Group 2; n = 697) at 2, 4, 6, and 12 months of age, with concomitant administration of routine pediatric vaccines (DTaP5-IPV/Hib, PCV13, rotavirus, hepatitis B, MMR, and varicella vaccines). Safety assessments included immediate unsolicited adverse events within 30 minutes post-vaccination, solicited injection site and systemic reactions within 7d, unsolicited AEs within 30d, serious adverse events (SAEs) including adverse events of special interest (AESIs), and medically attended adverse events (MAAEs) throughout the study. MenACYW-TT and MenACWY-CRM were overall well tolerated, and safety profiles were comparable. Solicited injection site reactions occurred in 84.9% and 84.6% of participants in Groups 1 and 2, respectively; solicited systemic reactions in 87.1% and 88.2%, respectively. During the entire study, 5.2% in Group 1 and 3.0% in Group 2 experienced at least one SAE; 0.9% and 0.1%, respectively, reported at least one AESI. Three deaths occurred in Group 1. All SAEs, AESIs, and deaths were unrelated to study vaccines. This study supports the safety profile of MenACYW-TT in infants and toddlers aged ≥ 6 weeks.Study registration: Clinicaltrials.gov: NCT03673462; EudraCT: 2019-004459-35.

Child, Preschool↗

PubMed2026

Comparison of immunogenicity, safety, and efficacy of EVA71 vaccine in children: a systematic review and meta-analysis.

INTRODUCTION: Enterovirus 71 (EV-A71) is a principal cause of hand, foot, and mouth disease (HFMD), potentially leading to severe neurological complications in children. Inactivated EV-A71 vaccines have been introduced. This study compares the immunogenicity, safety, and efficacy of EV-A71 vaccines versus placebo in pediatric populations. RESEARCH DESIGN AND METHODS: Following a PROSPERO-registered protocol, RCTs involving EV-A71 in children were identified via PubMed, Scopus, Cochrane, and ClinicalTrials.gov. Two independent reviewers performed screening, extraction, and RoB assessments (RoB 2.0). RESULTS: Five phase III RCTs involving 36,659 children were included. EV-A71 vaccination significantly increased seropositivity across follow-up periods, including early (RR 5.8), medium-term (RR 3.09), and long-term (RR 2.95) response. Seroconversion was significantly higher in the vaccinated group (pooled RR 13.04, 95% CI 2.80-60.61; p < 0.001). Geometric mean titers, analyzed using the ratio of means approach, were significantly higher in the vaccinated group during early and medium-term follow-up. Vaccine efficacy against EV-A71-associated HFMD exceeded 98% (pooled RR 0.02, 95% CI 0.01-0.09; p = 0.0028; I2 = 50%). Solicited local and systemic adverse events were mild and comparable between groups. CONCLUSION: Inactivated EV-A71 vaccines robust immunogenicity, high clinical efficacy, and an acceptable safety profile in children. Future studies should explore long-term protection, booster schedules, and multivalent formulations against non-EV-A71 serotypes.

Humans↗

PubMed2026

A multi-center, open-labelled, randomized controlled extended phase III non-inferiority clinical trial to evaluate the immunogenicity and tolerability of poliomyelitis vaccine (Vero cells), inactivated, Sabin strains administered with or without routine infant vaccines.

BACKGROUND: Oral poliovirus vaccine (OPV) has been reported to cause vaccine-derived poliovirus and vaccine-associated paralytic poliomyelitis, and the limited global supply of conventional IPV has led many countries to rely on fractional-dose IPV regimens alongside OPV. The current study aims to assess the sIPV safety and immunogenicity when given concurrently with or in a staggered manner with routine immunization. METHODS: A multi-country, multi-center, open-label, randomized controlled, extended phase III non-inferiority clinical trial was conducted with 1442 healthy infants aged 6-8 weeks from Bangladesh and Pakistan enrolled and randomized into four groups, i.e., co-administration group 1 (group C1), co-administration group 2 (group C2), staggered administration group 1 (group S1) and staggered administration group 2 (group S2). Antibody levels were determined using the collected sera for immunogenicity evaluation. The difference in seroconversion rates between the coadministration group and the staggered administration group is compared using the Cochran-Mantel-Haenszel χ2 (CMH-χ2) test, stratified by study site. Non-inferiority is concluded if the lower bound of the 95% confidence interval (CI) for the rate difference (coadministration group minus staggered administration group) is greater than -10%. The trial was registered prior to patient enrollment at clinicaltrials.gov (NCT05850364), and the protocol and statistical analysis plan are available at https://clinicaltrials.gov/study/NCT05850364. The trial is closed to new participants. FINDINGS: The post-vaccination seroconversion rates for PV I were 90.3% (306/339) in group C1 and 87.0% (261/300) in group S1, for PV II, 91.7% (311/339) in group C1 and 91.3% (274/300) in group S1 and for PV III, 86.4% (293/339) in group C1 and 92.3% (277/300) in group S1. Among adverse reactions (ARs) reported within 7 days of vaccination, the incidence was similarly high in both the co-administration and staggered vaccination groups (92.8% vs. 95.5%). INTERPRETATION: Our results demonstrated favorable safety and immunogenicity of co-administration of sIPV with other routine infant vaccines according to a 3-dose primary immunization schedule.

Humans↗

PubMed2026

Immunogenicity and safety of prophylactic HPV vaccines in people living with HIV: A systematic review and meta-analysis.

Human papillomavirus (HPV) is a major global public health concern, causing genital warts and cancers of the cervix, anus, oropharynx, vulva, and penis. People living with HIV (PLWH) face a disproportionately elevated burden of HPV infection and HPV-related malignancies due to chronic immunosuppression. We conducted a systematic review and meta-analysis searching six databases from January 2006 to June 2026 without language restrictions. Twenty-five studies were included in the systematic review; 12 independent studies (N = 1,493 for HPV16) were included in the quantitative meta-analysis. Using a DerSimonian-Laird random-effects model with logit transformation, pooled seroconversion rates were: HPV16 97.8% (95% CI: 94.9-99.1%; I2 = 89.6%; 15 datasets), HPV18 94.2% (95% CI: 86.1-97.7%; I2 = 95.8%; 13 datasets), HPV6 97.0% (95% CI: 93.7-98.6%; I2 = 66.1%; 10 studies), and HPV11 97.1% (95% CI: 90.5-99.1%; I2 = 95.5%; 10 studies). CD4 count was the most consistently reported modifier of immunogenic response: HPV16 seroconversion was 98.5% in PLWH with CD4 > 350 cells/μL vs. 71.1% in those with CD4 ≤ 200 cells/μL (ACTG A5240). All three vaccine generations demonstrated high immunogenicity. Two doses of the nonavalent vaccine were non-inferior to three doses in virologically suppressed women (Papillon RCT). No vaccine-related serious adverse events were reported. GRADE certainty of evidence was moderate for HPV16, HPV6, and HPV11, and low for HPV18. Prophylactic HPV vaccination achieves high seroconversion rates across all vaccine generations in PLWH. CD4 count significantly modifies vaccine response, underscoring the importance of vaccination before severe immunosuppression develops. These findings support current international recommendations advocating HPV vaccination for all PLWH.

Humans↗

PubMed2026

Immunogenicity and safety of inactivated TZ84- vs. HM175-based hepatitis A vaccines in pediatric populations: A systematic review and meta-analysis.

Individual studies indicate stronger and persistent long-term immunogenicity with TZ84-based than HM175-based hepatitis A vaccines. This systematic review and meta-analysis compared immunogenicity and safety of inactivated TZ84- and HM175-based hepatitis A vaccines in children and adolescents. Studies involving adults, immunocompromised populations, non-comparative designs, non-English publications, and studies with non-extractable outcomes were excluded. MEDLINE/PubMed, Google Scholar, other electronic databases, and grey literature were searched (September-October 2025). Risk of bias was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool, and meta-analyses were performed where appropriate. Seven publications arising from four randomized cohorts (total participants: 3,282) reporting seroconversion rates (SCRs), geometric mean concentrations (GMCs), long-term seroprotection, and adverse events (AEs) were identified. Pooled analyses demonstrated higher SCRs and GMCs with TZ84 than HM175-based vaccines following both one and two doses. SCRs at 1 month [odds ratio (OR): 3.05; 95% confidence interval (CI): 1.88-4.96] and GMCs at 7 months [standardized mean difference (SMD): 0.88; 95% CI: 0.18-1.58; p = .01] both favored TZ84-based vaccines. Long-term follow-up (up to 186 months/15.5 y) showed higher reported anti-HAV antibody concentrations for TZ84-based vaccines. The AEs were comparable between vaccine types (RR: 0.95; 95% CI: 0.76-1.20; p = .69). Evidence was limited by the small number of unique randomized cohorts, geographic concentration in China, heterogeneity across studies, and reliance on surrogate immunogenicity outcomes. Overall, available evidence suggests that TZ84-based hepatitis A vaccines (HAPIBEV™/HEALIVE®) are associated with higher reported antibody responses and greater reported antibody persistence than the HM175-based vaccine (HAVRIX®) in children and adolescents, with comparable safety profiles.Registration: PROSPERO CRD420251154480.

Humans↗