Vaccination Schedule Research Articles

Protektem pikinini blong yu trial: protocol for a single arm field trial to assess the effectiveness of treating-all pregnant women with hepatitis B infection with tenofovir prophylaxis to prevent mother-to-child transmission in Vanuatu, 2024–2025

BackgroundHepatitis B infection is a major public health concern in Vanuatu, with approximately 9% of the general population estimated to be living with chronic hepatitis B. Most new infections are due to mother-to-child transmission (MTCT). Hepatitis B vaccination is available in Vanuatu, but coverage rates for first dose within 24 h of birth and third dose are suboptimal. While treatment of chronic hepatitis B infection with tenofovir disoproxil fumarate (TDF) is available in country, there is no capacity to test hepatitis B e antigen and limited capacity to test hepatitis B virus (HBV) DNA viral load, which is a current eligibility requirement for women in pregnancy to access hepatitis B prophylaxis for MTCT per National guidelines. Recently, the World Health Organization guidelines have been updated to recommend universal peripartum antiviral prophylaxis (PAP) of pregnant women living with hepatitis B to prevent MTCT of HBV, without assessment of viral load in places without access to testing. However, these recommendations are conditional based on low-certainty evidence. The aim of this trial is to evaluate the effectiveness and safety of universal PAP and provide evidence for the global guidelines.MethodsA single arm field trial compared to real world control sites will be conducted in Vanuatu involving pregnant women attending antenatal care services with positive HBsAg rapid tests. Participants at the control sites will undergo routine care. Participants at the intervention sites will all receive oral TDF prophylaxis from second trimester to completion of infant primary hepatitis B vaccination schedule. Primary data analysis will be by intention-to-treat. Initial analyses will be unadjusted comparisons of the intervention sites and control sites. Adjusted analyses will be performed, as needed, and presented in addition to unadjusted comparisons.DiscussionThis study will provide evidence of acceptability, effectiveness and cost-effectiveness of prophylaxis for all women with hepatitis B during pregnancy, as per the updated WHO guidelines, compared with current practice. The outcome of this trial will provide critical information to inform national and global guidelines around universal peripartum antiviral prophylaxis for hepatitis B during pregnancy.Trial registrationAustralian New Zealand Clinical Trials Registry (ANZCTR), ACTRN: ACTRN12623001202651p. Registered 21 November 2023.

Vaccination Schedule and Age Influence Impaired Responsiveness to Hepatitis B Vaccination: A Randomized Trial in Central Asia

Vaccination against hepatitis B virus (HBV) is the most cost-efficient measure to prevent infection. Still, vaccination coverage among adults in Central Asia, including Kyrgyzstan, remains suboptimal, and data about immune responses to HBV vaccination are lacking. HBV vaccination is given as three injections, whereby the second and third doses are given 1 and 6 months after the first (0-1-6 scheme). However, compliance with the third dose is low in Kyrgyzstan, presumably due to the long time interval between the second and third doses, suggesting that a shortened vaccination schedule could result in better adherence and increased seroconversion. Thus, we conducted a randomized trial of individuals aged 17–66 years comparing the 0-1-6 scheme against a shorter 0-1-3 scheme. Primary outcome measures were post-vaccination titers and the percentage of participants with protective post-vaccination titers (≥10 mIU/mL). Compliance with the completeness of blood draws and administered third vaccine dose was better with the 0-1-3 scheme than with the 0-1-6 scheme. In both study arms combined, younger age (<40 years) was associated with better vaccine protection. The 0-1-6 scheme resulted in higher post-vaccination titers (52 versus 15 mIU/mL, p = 0.002) and a higher seroprotection rate (85% versus 64%, p = 0.01) than the 0-1-3 scheme, whereby post-vaccination titers correlated negatively with age in the 0-1-3 scheme. Thus, the 0-1-6 scheme should continue to be the preferred HBV vaccination schedule, but interventions to improve compliance with the third vaccine dose are needed.

Evaluation of the knowledge levels of university students about Human Papilloma Virus

Aim: Human papilloma virus (HPV) is the most common viral infection agent of the reproductive system. A large portion of sexually active women and men are infected with this virus at some point in their lives. The aim of this study was to examine the knowledge, attitudes and behaviors of university students about HPV vaccines. Materials and Methods: The research survey was applied to volunteer undergraduate students receiving health education as an online Google survey. The survey form consists of a total of 24 questions aimed at evaluating demographic information and knowledge about HPV vaccines. The results were transferred to spreadsheets and evaluated using Microsoft Excel and SPSS Version 25.0 statistical package programs. Results: A total of 300 students participated in the study. According to the descriptive statistics results, 71% of the participants were female, 92% were studying in the health field (medicine, dentistry, first and emergency aid, physiotherapy, nursing, etc.) and 8% were studying in departments other than health. While 7% of the students stated that they had received the HPV vaccine, 36% stated that they wanted to receive the HPV vaccine; 45% were undecided about receiving the vaccine. While 63% of the students thought that HPV vaccines should be included in the routine vaccination schedule; 33% were hesitant. When asked the question “If you recommend the HPV vaccine, to whom would you recommend it?”, 17 of the students responded “To women and men with a family history of cervical cancer”, 208 of the students responded “to both men and women”, 43 of them responded “to all women”, and 10 of them responded only “to women with a family history of cervical cancer”; 22 of the students reported that they did not recommend the HPV vaccine. When the reasons for not recommending the HPV vaccine were examined, 10 of the students stated that they did not recommend the HPV vaccine due to doubts about the safety of the vaccine, 10 of them stated that they were afraid of possible negative outcomes, and 2 of them stated that they did not recommend the HPV vaccine due to difficulties in receiving adequate counseling. Conclusion: Our study found that university students have low knowledge about HPV vaccine and infection and the vaccination rate is also low (7%). Multidisciplinary public health studies should be conducted to provide the necessary education and counseling to ensure that university students are informed about HPV vaccine.

Exploratory assessment of the parent attitudes about childhood vaccines survey tool to assess vaccine hesitancy and pet vaccination status among pet owners.

To assess the applicability of the parent attitudes about childhood vaccines (PACV) survey to pet owners and its association with vaccine hesitancy. A national survey including an adapted version of the PACV was administered to 2,853 dog and 1,977 cat owners. Respondents were queried about the vaccination status of their pets. Exploratory factor analysis, Mokken scale analysis, Cronbach α, McDonald ω, and bivariate analyses were used to assess the validity and reliability of the PACV and shortened versions. The Fisher exact test and linear probability models were used to assess the association between the PACV and other factors and vaccination status. The PACVs for pet owners were valid and reliable with high internal consistency and served as correlates for vaccination status. In multivariate analyses, long-term relationships with veterinarians were also associated with vaccination. Individual survey items indicated substantial concerns about vaccine safety, side effects, and efficacy. Most respondents indicated trust and good relationships with their veterinarian, had not avoided or delayed vaccinations, understood the severity of pet diseases, supported the recommended vaccine schedule, and did not self-identify as vaccine hesitant (VH). The PACV identified 21.7% of dogs and 25.9% of cat owners as VH. The full and the reduced versions of the PACV are valid and reliable tools to assess VH status in dog and cat owners. The PACV could serve as an important tool for veterinary researchers to identify factors associated with vaccine hesitancy and develop effective interventions.

Seroprevalence study reveals pertussis underreporting in Brazil and calls for adolescent/young adult boosting: mouse model demonstrates immunity restoration.

Pertussis continues to pose a significant threat despite the availability of effective vaccines. The challenge lies in the vulnerability of infants who have not yet completed their vaccination schedule and in adolescents and adults becoming potential disease carriers. We evaluated the seroprevalence of pertussis immunity in a cohort of 1,500 healthy Brazilian volunteers. Next, we explored the potential restoration of waning pertussis immunity by administering booster doses of wP, aP or Plow (an economically viable and low reactogenic vaccine in development at Butantan) using a mouse model. The mean anti-PT IgG levels in the Brazilian volunteers was 39.4 IU/mL. Notably, individuals ≤ 19 years exhibited higher IgG values compared to older age groups (≥ 20 y). Overall, 8.4% of the samples displayed indications of recent or current contact/infection, with IgG levels surpassing 120 IU/mL, particularly in the 15-19 years age group. IgM values were also increased in the 10-19 years age group. Potential recovery of pre-existing but waning immunity investigated in mice, showed that boosting with wP induced higher antibody titers than aP or Plow. Notably, aP and Plow boosts prompted superior effector and memory cell responses from both B and T cells. Upon challenge with B. pertussis, aP or Plow boost provided greater protection as compared to wP. Pertussis appears to circulate predominantly among adolescents and young adults. Insights from the mouse model indicate that immunity can be restored with booster doses. Boosting immunity in non-targeted groups could prevent the dissemination of pertussis to infants.

Immunogenicity and Safety According to Immunosuppressive Drugs and Different COVID-19 Vaccine Platforms in Immune-Mediated Disease: Data from SAFER Cohort

Background/Objectives: The effectiveness of COVID-19 vaccine in patients with immune-mediated inflammatory diseases (IMID) depends on the underlying disease, immunosuppression degree and the vaccine regimens. We evaluate the safety and immunogenicity of different COVID-19 vaccine schedules. Methods: The SAFER study: “Safety and effectiveness of the COVID-19 Vaccine in Rheumatic Disease”, is a Brazilian multicentric prospective observational phase IV study in the real-life. Data were analyzed after 2 or 3 doses of COVID-19 vaccines: adenoviral vectored vaccine (ChAdOx1 nCoV-19, Astrazeneca), mRNA vaccine (BNT162b2, Pfizer–BioNTech) or inactivated SARS-COV-2 vaccine (CoronaVac, Sinovac Biotech). IgG antibody against SARS-CoV-2 spike (IgG-S) receptor-binding domain level were quantified at baseline (T1) and 28 days after the first (T2), 2nd (T3) and 3rd (T4) doses by chemiluminescence (SARS-CoV-2-IgG-II Quant-assay, Abbott-Laboratories). Results: 721 patients with IMID were included in the analysis. The median titers of IgG-S (BAU/mL) increased progressively over the times: at baseline was 6.26 (5.41–7.24), T2: 73.01 (61.53–86.62), T3: 200.0 (174.36–229.41) and T4: 904.92 (800.49–1022.97). The multivariate linear regression showed that greater IgG-S titers were associated with pre-exposure to COVID-19 (p < 0.001) and BNT162b2 booster vaccine (p < 0.001). Rituximab and immunosuppressant drugs were independent factors for low titers (p = 0.002, p < 0.001, respectively). No serious adverse event was reported. Conclusions: All platforms were safe and induced an increase in IgG-S antibodies. COVID-19 pre-exposure and BNT162b2 booster regimens were predictors of higher humoral immune responses, which is relevant in immunosuppressed populations. Immunosuppressants (mainly rituximab) predicted the lowest antibodies.

The Politics of Scheduling: Vaccination as Infrastructure, Spectacle, and Market in West Africa, 1960s–1980s

Vaccination schedules negotiate the timing of interactions among bodies, vaccines, and pathogens. Yet they do more: they orchestrate the movement of vaccines through factories, business plans, injecting devices, fridges, vehicles, healthcare labour, kinship relations, policy models, government budgets, and so on. This article approaches vaccine schedules as standards that synchronise the varying entities – and interests animating these – that make up vaccination infrastructures broadly defined. What unfolds is an examination of the politics of schedule-setting and implementation, set-out in three debates concerning vaccination in West Africa during a time of fitful, contested expansion in both the delivery of immunizing technologies and the development of basic healthcare infrastructure. The first debate concerns rhythms of vaccination during the US-led and funded West African Smallpox Eradication and Measles Control Program (SEMCP) in the latter 1960s, revealing tensions among this programme’s technopolitical priorities. Two later debates, about the optimal age for measles vaccination, and the minimum total doses/visits required for full immunization, reflect broader contests, from the late 1970s to the late 1980s, over the ultimate goals of the ‘Expanded Programme on Immunization’ (EPI). These three debates provide insight into how multiple actors vied for control over how routine childhood vaccination was to be enacted and imagined in West Africa.

Prevalence and factors contributing to missed opportunities for vaccination in Mogadishu, Somalia

BackgroundVaccination is a critical public health intervention that significantly reduces morbidity and mortality from vaccine preventable diseases. Despite the proven benefits of vaccines, missed opportunities for vaccination (MOV) remain a significant challenge in many low-income countries, including Somalia. This study aimed to determine the prevalence and identify the factors contributing to MOV in Mogadishu, Somalia. MethodsA cross-sectional study was conducted at various healthcare facilities in Mogadishu, Somalia, from January to March 2024. A total of 234 caregivers of children under five years of age were interviewed using a structured questionnaire. Data on sociodemographic characteristics, health service utilization, and reasons for missed vaccinations were collected. Logistic regression analysis was used to identify factors associated with MOV. Results: The prevalence of MOV in Mogadishu was 26%. Key factors contributing to MOV included low socioeconomic status, lack of caregiver awareness about vaccination schedules, logistical challenges within the healthcare system, and misconceptions about vaccine safety and efficacy. Knowledge and beliefs of mothers about vaccination significantly affected the MOVs in children. Not knowing if all children should be vaccinated is associated with higher probability of (MOVs), (AOR =13.006, 95% CI = 1.175-143.924, p = 0.003). ConclusionThe study highlighted a significant prevalence of missed opportunities for vaccination in Mogadishu, Somalia. Addressing these missed opportunities requires a multifaceted approach, including enhancing public awareness about the importance of vaccination, improving healthcare infrastructure, and ensuring consistent vaccine supply and proper storage.

Uptake of Measles Second Dose Vaccine and Its Associated Factors Among Children Age 24-35 Months in Merhabete Woreda, Ethiopia: 2022: A Cross-Sectional Study.

Measles infection in children causes a high degree of morbidity and mortality. Vaccination with two doses of measles vaccine is the best strategy to prevent infection and its spread to other children. However, measles containing vaccination coverage in Ethiopia is below the WHO elimination goal. In this study, our aim was to assess uptake of measles second dose and its associated factors among children's age 24-35 months in Merhabete, North Shoa, Ethiopia, 2022. A community-based cross-sectional study design was conducted in Merhabete Woreda from June 1 to 30, 2022. A total of 732 children aged 24-35 months were included using a multistage and systematic random sampling technique. Data were collected using a semi-structured, interviewer-administered questionnaire. Verbal informed consent was taken regarding their willingness to participate in the study from the guardians. The information was kept confidential and not shared with a third party. Data entered into EpiData version 4.6 and exported to SPSS version 25. A logistic regression model was used to identify associated factors. AOR with 95% CI and p < 0.05 were used to declare statistically significant variables. A total of 732 children with a response rate of 94.6% were included; the median age was 28 months. Uptake of measles vaccine second dose was 63.3% (95% CI 60%-67%). Knowledge of measles second dose schedule (AOR = 2.151, 95% CI 1.053-4.396), birth at a healthcare facility (AOR = 3.502, 95% CI 1.58-7.77), > 4 antenatal care visits (ANC) (AOR = 2.56, 95% CI 1.254-5.225), having immunization card (AOR = 9.958 (4.256-23.298), and mother age 25-34 years (AOR = 2.954, 95% CI 1.298-6.721) were significantly associated with the uptake of measles second dose. The uptake of measles second dose vaccine in Merhabete Woreda was below the WHO measles elimination target of > 95%. Variables such as number of antenatal follow-up visits, institutional delivery, knowing the schedule of measles second dose vaccine, maintaining immunization card records, and maternal age were found to be independent predictors of vaccination. Therefore, Woreda Health Office managers should strengthen periodic monitoring and evaluate the implementation of measles second dose vaccine. Health professionals should also improve mother's awareness on measles second dose vaccine schedule and its importance and retain their immunization chart booklet.

Prevalence and Genetic Diversity of Respiratory Syncytial Virus Reinfections in Young Thai Children, 2016-2023.

Although a vaccine for respiratory syncytial virus (RSV) is now available for pregnant women and the elderly, RSV remains a significant cause of respiratory illness in children globally. Reinfections by the same or different RSV subgroups in children residing in the tropics are currently under-studied. Therefore, we examined the patterns of RSV infection and reinfection in Thai children aged ≤ 5 years with respiratory symptoms from 2016 to 2023. Screening of 7710 pediatric respiratory specimens identified 1245 RSV-positive samples (16.1%), mostly from the rainy months (July-November). Interestingly, 74 children experienced two infections, and 6 had three infections. Reinfection by different RSV subgroups occurred in 30 children: 21 were initially infected with RSV-B and later with RSV-A, while 9 had the reverse pattern. Reinfections only by either RSV-A or RSV-B were observed in 22 and 2 children, respectively, with one child infected with RSV-A three times. All RSV-A reinfections belonged to the ON1 genotype, while RSV-B reinfections were BA9. Notably, reinfections across different seasons were observed within homologous pairs. These findings suggest a transitory immunity to natural RSV infection and provide the knowledge that may help optimize pediatric vaccination schedule. Ongoing epidemiological data on RSV are essential in monitoring genotype circulation and vaccine effectiveness.

An optimised rabies vaccination schedule for rural settlements

An optimised rabies vaccination schedule for rural settlements

Effect of a Reduced PCV10 Dose Schedule on Pneumococcal Carriage in Vietnam

BackgroundAfter pneumococcal disease and colonization have been controlled through vaccination campaigns, a reduced pneumococcal conjugate vaccine (PCV) schedule may be sufficient to sustain that control at reduced costs.MethodsWe investigated whether a single primary dose and booster dose (1p+1) of the 10-valent PCV (PCV10) would be noninferior to alternative dose schedules in sustaining control of carriage of pneumococcal serotypes included in the vaccine. In Nha Trang, Vietnam, an area in which PCV had not been used previously, a PCV10 catch-up campaign was conducted in which the vaccine was offered to children younger than 3 years of age, after which a cluster-randomized trial was conducted in which children received PCV10 at 2, 3, and 4 months of age (3p+0 group); at 2, 4, and 12 months of age (2p+1 group); at 2 and 12 months of age (1p+1 group); or at 12 months of age (0p+1 group). Annual carriage surveys in infants (4 to 11 months of age) and toddlers (14 to 24 months of age) were conducted from 2016 through 2020. The primary end point was protection against carriage of vaccine serotypes, evaluated in a noninferiority analysis in the 1p+1 group as compared with the 2p+1 and 3p+0 groups, 3.5 years after vaccine introduction (noninferiority margin, 5 percentage points). Noninferiority of the 0p+1 schedule was also evaluated.ResultsIn 2016, before the introduction of PCV10, vaccine-serotype carriage was found in 160 of 1363 infants (11.7%); in 2020, vaccine-serotype carriage was found in 6 of 333 (1.8%), 5 of 340 (1.5%), and 4 of 313 (1.3%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively, indicating noninferiority of 1p+1 to 2p+1 (difference, 0.3 percentage points; 95% confidence interval [CI], −1.6 to 2.2) and to 3p+0 (difference, 0.5 percentage points; 95% CI, −1.4 to 2.4). Similarly, 1p+1 was noninferior to 2p+1 and 3p+0 for protection against vaccine-serotype carriage among toddlers. In 2016, carriage of serotype 6A was found in 99 of 1363 infants (7.3%); in 2020, it was found in 12 of 333 (3.6%), 10 of 340 (2.9%), and 3 of 313 (1.0%) infants in the 1p+1, 2p+1, and 3p+0 groups, respectively. The 0p+1 schedule was also noninferior to the other three dose schedules among infants and toddlers, although cross-protection against serotype 6A was less common than with the other vaccination schedules. No PCV10-associated severe adverse effects were observed.ConclusionsA reduced vaccination schedule involving a single primary dose and booster dose of PCV10 was noninferior to alternative schedules in protecting against vaccine-serotype carriage in infants and toddlers. (Funded by the Bill and Melinda Gates Foundation and others; ClinicalTrials.gov number, NCT02961231.)

Epidemiology of Pertussis After the COVID-19 Pandemic: Analysis of the Factors Involved in the Resurgence of the Disease in High-, Middle-, and Low-Income Countries

Pertussis is a highly contagious bacterial disease of the respiratory tract that can be prevented by vaccination. Before the COVID-19 pandemic, the vaccine coverage rate for the third dose of a DPT-containing vaccine was 86%, with large disparities among countries. Since 2022, many high-income countries have reported a resurgence of pertussis, especially in the European region, but the disease has also caused outbreaks in middle- and low-income countries, despite their less extensive disease surveillance capacities. This paper aims to review the incidence rates (IRs) of pertussis in high-, middle-, and low-income countries following the COVID-19 pandemic and to discuss the most relevant factors associated with the resurgence of the disease. The epidemiology of pertussis is highly variable and is influenced not only by the type of vaccine used but also by the specific characteristics of the disease, vaccine coverage rates, vaccination schedules, and the quality of surveillance. Since the cessation of COVID-19 measures, there have been significant pertussis outbreaks that could have been partially mitigated with higher coverage rates and more comprehensive pertussis vaccination throughout life.

Timeliness of 24 childhood immunisations and evolution of vaccination delay: Analysis of data from 54 low- and middle-income countries.

Vaccination timeliness is often not considered among standard performance indicators of routine vaccination programmes, such as vaccination coverage, yet quantifying vaccination delay could inform policies to promote in-time vaccination and help design vaccination schedules. Here, we analysed vaccination timeliness for 24 routine childhood immunisations for 54 countries. We extracted individual vaccination status and timing from Demographic and Health Surveys data from 54 countries with surveys from 2010 onwards. Individual data was used to estimate age at vaccination for <5 year-old children. Recommended age of vaccination for each country and vaccine was compared to the age at vaccination to determine vaccination delay. The evolution of vaccination delay over time was described using estimates from different birth cohorts. To identify socio-demographic indicators associated with delayed vaccination, we used multivariable Cox regression models with country as random effect and estimated the Hazard Ratio for vaccination with each vaccine-dose for each week post recommended vaccination age. Vaccine coverage at the recommended age was highest for birth and first doses (e.g. 50.5% BCG, 18.5% DTP-D1) and lowest for later doses (e.g. 5.5% DTP-D3, 16.3% MCV-D1, 8.2% MCV-D2). Median delay was lowest for birth doses, e.g. BCG (1 week (IQR: 0 to 4)), and it increased with later doses in vaccination courses: 1 (0, 4) week for DTP-D1 versus 4 (2, 9) weeks for DTP-D3. Although the median delay for each vaccine-dose remained largely constant over time, the range of delay estimates moderately decreased. Children living in rural areas, their countries' poorer wealth quintiles and whose mothers had no formal education were more likely to received delayed vaccinations. Although we report most children are vaccinated within the recommended age window, we found little reduction on routine immunisation delays over the last decade and that children from deprived socioeconomic backgrounds are more likely to receive delayed vaccinations.

Analysis of Implementation Strategies for Nationwide HPV Vaccination Programs Across European Union Countries

Background/Objectives: Human papillomavirus (HPV) vaccination programs play a critical role in the primary prevention of HPV-related diseases, including cervical cancer. However, the principles governing the implementation of these programs vary across European Union (EU) countries. The objective of this study was to analyze and compare the strategies for implementing HPV vaccination programs across the EU, with a focus on access, vaccine selection, and procurement processes. Methods: This study utilized a comprehensive review of official websites from government bodies, public health organizations, and dedicated vaccination platforms in each of the 27 EU member states. Additionally, a search of Tenders Electronic Daily (TED) was conducted to examine the criteria used in tendering processes for vaccine suppliers involved in national HPV vaccination programs. Results: All 27 EU countries provide public funding for HPV vaccination, with 26 countries offering free vaccination for both girls and boys. In 22 of these countries, the nine-valent HPV vaccine is the only option available for free under national programs. Estonia and Ireland are exceptions, where a single dose of Gardasil 9 is administered. Most countries adhere to the approved vaccination schedules, though slight variations exist. The predominant criterion for selecting vaccine suppliers in national tenders is the lowest price offered. Conclusions: HPV vaccination programs across the EU are uniformly funded through public health systems, yet access to free vaccination and specific program details vary by country. These variations reflect the diverse healthcare systems and procurement strategies in place, which can impact the systemic approach to HPV prevention. Further harmonization of vaccine procurement and implementation strategies may enhance the effectiveness and equity of HPV vaccination across Europe.

Association between long-term exposure to air pollutants with breakthrough SARS-CoV-2 infections and antibody responses among COVID-19 vaccinated older adults in Northern Italy

AimsTo investigate the association between long-term exposure to PM2.5, PM10, NO2 and O3 with SARS-CoV-2 breakthrough infections and COVID-19 vaccine-induced antibody responses in a northern Italian population-based sample of older adults. MethodsWithin an ongoing prospective population-based study, we followed-up 1326 vaccinated individuals aged 65–83 years, with no prior SARS-CoV-2 infection, for their first positive SARS-CoV-2 swab until December 31st, 2022. We assessed spike IgG antibody levels in most participants (n = 1206). The 2019 annual mean levels of air pollutants derived from combined use of chemical-transport and random-Forest models (spatial resolution: 1Kmq) were individually assigned based on the latest residence address. We estimated multivariable-adjusted associations (per 1 interquartile range increase, IQR) of air pollutants with breakthrough infections using Cox models with time-dependent vaccine exposure; and with percent change in the IgG geometric mean using generalized additive models. ResultsThe mean (SD) age was 74.9 ± 4.1 years, and 50% were women. An IQR (1.2 μg/m3) increase in long-term PM2.5 exposure was associated with a 52% increase in breakthrough infection risk following a second vaccine and a 26% increase following a third vaccine. The effect vanished with the further increment of vaccination doses. Associations for NO2 were inconsistent. Ozone was negatively associated with breakthrough infection risk, but this association reversed in bi-pollutant models adjusting for PM2.5. PM2.5 was associated with a −7.3% (−13.9% to −0.2%) reduction in vaccine-induced IgG levels. The reduction became more pronounced as the time delay from vaccination increased, and with adjustment for NO2 co-exposure. ConclusionIn our population of vaccinated older adults, fine particulate matter exposure was independently associated with a higher risk of SARS-CoV-2 breakthrough infection and a lower antibody response, both effects being influenced by timely and repeated vaccination schedule.

Public Health Impact of Introducing a Pentavalent Vaccine Against Invasive Meningococcal Disease in the United States.

Invasive meningococcal disease (IMD) is primarily associated with five Neisseria meningitidis serogroups: A, B, C, W, or Y. In the United States (US), available vaccines protect against serogroups B (MenB), A, C, W, and Y (MenACWY), and A, B, C, W, and Y (MenABCWY). The Advisory Committee on Immunization Practices is re-evaluating the adolescent meningococcal vaccination schedule with varying recommendation formats. This analysis aimed to predict which schedule could avert the most IMD cases and have the most positive public health impact (PHI). An epidemiological model compared the 15-year PHI of vaccination schedules using MenB, MenACWY, and/or MenABCWY vaccines versus current US standard of care (SoC). Varying coverage rates reflected routine, shared clinical decision making, and risk-based recommendations. Sensitivity analyses assessed robustness of the results to different inputs/assumptions. The most positive PHI compared with SoC was observed with one dose of MenACWY at 11 years of age and two doses of MenABCWY (6 months apart) at 16 years of age, assuming routine recommendation and coverage reflecting real-world uptake of MenACWY. This strategy resulted in 123 IMD cases averted (MenB: 59, MenACWY: 64), 17 deaths prevented, 574 life-years saved, and 757 quality-adjusted life-years gained versus SoC. Eliminating MenACWY vaccination at 11 years was found to result in an additional IMD burden. A routinely recommended two-dose pentavalent vaccine, with doses administered 6 months apart at 16 years of age, alongside the routinely recommended MenACWY vaccine at 11 years of age, would improve the PHI and benefits of IMD vaccination to society.

Childhood Mandatory Vaccinations: Current Situation in European Countries and Changes Occurred from 2014 to 2024.

Background/Objectives: Vaccination is one of the most effective public health interventions, preventing millions of deaths globally each year. However, vaccine hesitancy, driven by misinformation and reduced disease risk perception, has led to declining vaccination rates and the resurgence of vaccine-preventable diseases (VPDs) in Europe. In response to this, countries have implemented various strategies, including mandatory and recommended vaccination programs. The objective of this study is to map the current European landscape of pediatric vaccination policies, and the variations that have occurred in the last decade. Methods: This rapid review was conducted on PubMed, Google, and the European Centre for Disease Prevention and Control website, to collect all vaccination schedules in EU/EEA countries in 2024 and all documents focusing on the introduction of mandatory vaccines during the last decade. Results: As of 2024, 13 countries had at least one mandatory pediatric vaccination, with France, Hungary, and Latvia requiring all but one vaccine. In contrast, 17 countries had no mandatory vaccinations, relying only on recommendations. Between 2014 and 2024, six countries (Croatia, France, Germany, Hungary, Italy, and Poland) introduced or extended mandatory vaccinations. Conclusions: European vaccination policies show significant variation. Effective programs depend on robust healthcare systems, public trust, and adaptable strategies to address vaccine hesitancy and the resurgence of VPDs.

Awareness and Knowledge of Hepatitis B Vaccination Among Newly Enrolled First-Year Medical Undergraduates in South India: A Cross-Sectional Survey.

Hepatitis B poses a significant public health risk, particularly for healthcare professionals who face heightened exposure in clinical settings. This study assesses the awareness and knowledge of hepatitis B vaccination among first-year medical undergraduates in their preclinical stage before transitioning to clinical phases. This cross-sectional survey was conducted among newly enrolled first-year medical undergraduate students at a medical college before the commencement of a planned vaccination drive, allowing the institution to assess baseline knowledge and logistical needs for the drive. A self-administered questionnaire was used to evaluate students' awareness and understanding of hepatitis B transmission, vaccination, and the occupational risks associated with healthcare work. The data gathered from this survey provided critical insights for optimizing the logistics and educational components of the upcoming vaccination program for the incoming cohort. Among the 126 respondents, there was a slightly higher representation of male participants (53.17%, n=67), while 46.83% (n=59) were females. Awareness of hepatitis B as a highly contagious liver infection was high, with 88.9% of students agreeing or strongly agreeing. The knowledge that hepatitis B is a public health concern and can lead to severe conditions such as liver cancer was similarly prevalent (97.6% and 90.4%, respectively). Most respondents (80.2%) were aware of the heightened risk for healthcare professionals and viewed vaccination as an effective preventive measure (96.1%). Awareness of transmission routes, including contact with infected blood (96%) and unprotected sexual contact (97.6%), was also strong. However, fewer students were informed about the recommended vaccination schedule (63.4%) or the necessity of booster doses for high-risk individuals (70.6%). Additionally, 93.7% believed healthcare workers should be vaccinated, while 88.9% recognized the need for immunity status checks in healthcare settings. Only 16.66% (n=21) reported receiving the hepatitis B vaccine, with 14.28% having completed the full three-dose series, while 2.38% received only one or two doses. A significant portion (62.69%) reported not being vaccinated, and 20.63% were unsure of their vaccination status. Key reasons for incomplete vaccination included lack of awareness about the full series (58.73%), fear of side effects (6.34%), and perceived lack of necessity (7.93%). Access challenges were also noted by 2.38% of students. Only 1.58% of respondents had checked their immunity status through anti-hepatitis B surface antibody (HBsAb) testing. Newly enrolled medical undergraduates show substantial foundational knowledge of hepatitis B and its prevention. However, targeted educational and peer-led initiatives are recommended to bridge the remaining gaps, ensuring future healthcare professionals have comprehensive knowledge for effective hepatitis B prevention. The findings also underscore the need for improved vaccination awareness and accessibility to achieve comprehensive immunization among medical undergraduates.

Assessment of Antibody Levels and Vaccine-induced Serologic Responses After Completion of Cancer Treatment in Pediatric Patients: A 6-year Experience in Turkey on HAV, HBV, VZV, and MMR Vaccinations

Objective: Childhood cancer treatment disrupts vaccination schedules and weakens or eliminates vaccine-induced immunity. In addition, post-treatment vaccine responses vary. This study aimed to assess post-treatment serum antibody levels and vaccine responses in children. Methods: Pediatric patients treated at Hacettepe University between years 2015 and 2020, achieved remission after chemotherapy for lymphoma and solid tumors were included. Post-treatment vaccination status, serum antibody levels for hepatitis A (HAV), hepatitis B (HBV), varicella-zoster (VZV), measles-mumps-rubella (MMR), and changes in vaccine responses were retrospectively analyzed. Results: The study included 533 patients. Post-treatment seronegativity rates were: measles (83.5%), HAV (64%), rubella (60.1%), HBV (48.5%), VZV (43.3%), and mumps (28%). Post-treatment antibody loss was observed for measles (47.1%), HAV (31.9%), HBV (31.4%), mumps (28.6%), VZV (21.7%), and rubella (11.4%). Seropositivity after 1 vaccine dose was seen with HAV (83.6%), rubella (82.9%), HBV (81.4%), VZV (63.5%), mumps (45.4%), and measles (33.3%). Seropositivity after 2 vaccine doses was achieved with HAV (98.8%), VZV (84.6%), rubella (80%), HBV (80%), measles (32.2%), and mumps (36.2%). Conclusion: Post-treatment serological vaccine responses in children were lower than anticipated despite multiple doses. Given the potential need for periodic serological assessments and booster vaccinations, long-term follow-ups are planned.