Research Content Recommendation
01
Independent and joint associations of sex and birth order with non‑national immunization program vaccine coverage among Chinese children: a cross-sectional analysis
This article, authored by Xiaolin Xu （Zhejiang University）and colleagues and published in the International Journal for Equity in Health, aims to evaluate the independent and joint effects of sex and birth order on non-National Immunization Program (non-NIP) vaccine coverage among children aged 1–6 years in China, and to examine whether these associations are moderated by family sociodemographic characteristics.
The study employed a cross-sectional design and was conducted between July and October 2022 in Zhejiang and Henan provinces. Eligible participants were children aged 1–6 years and their primary caregivers who had resided locally for ≥6 months and had no contraindications to vaccination. Data were collected through face-to-face questionnaire interviews, which captured the child’s sex, birth order, vaccination records for five non-NIP vaccines [Haemophilus influenzae type b (Hib), rotavirus, enterovirus 71 (EV71), varicella, and 13-valent pneumococcal conjugate vaccine (PCV13)], as well as caregiver sociodemographic information. The primary outcome was completion of non-NIP vaccination, defined as receipt of at least one dose of any three of the five vaccines.
A total of 1,611 children were included in the analysis, 48.0% of whom were female, and 51.1% were first-born. Overall coverage differences indicated that boys had higher non-NIP vaccine coverage (51.2%) than girls (46.6%), and first-born children had significantly higher coverage (54.9%) than second-born (44.3%) and third-or-later-born children (32.5%). Independent association analysis showed that birth order was negatively associated with non-NIP vaccine completion (p for trend < 0.001). After multivariable adjustment, the prevalence ratios (PRs) for vaccine completion were significantly lower for second-born (PR: 0.85, 95% CI: 0.76–0.93) and third-or-later-born children (PR: 0.82, 95% CI: 0.65–1.00), compared to first-borns. The association with sex was not statistically significant after adjusting for sociodemographic factors (PR = 0.94).
Interaction analysis revealed a significant joint effect of sex and birth order: third-or-later-born girls had the lowest non-NIP vaccine coverage (28.4%), representing a 29% reduction compared to first-born boys (PR: 0.71, 95% CI: 0.49–0.97). Additionally, second-born girls showed a significant multiplicative interaction effect (PR: 0.86, 95% CI: 0.75–0.98). Stratified analyses found that the effects of sex and birth order were more pronounced in rural areas and among families with caregivers of lower educational attainment.
The study highlights substantial inequalities in non-NIP vaccination coverage among children in China, particularly among later-born children and girls. These findings underscore the need for targeted interventions to address disparities in coverage with non-NIP vaccines associated with recent changes in fertility policy, including the implementation of health education programs in rural areas and among low-education populations and financial subsidy policies for non-NIP vaccines.
https://doi.org/10.1186/s12939-025-02502-6
02
The “Whole-Of-Society” Approach for Misinformation Correction: How Expert Didactic TikTok Videos Motivate Citizen Fact-Checking and Vaccine Promotion
This article, published in the Journal of Health Communication, employs an experimental design to examine how expert-produced didactic corrective TikTok videos influence public perceptions of source credibility, thereby motivating citizen engagement in COVID-19 vaccine misinformation correction and vaccine promotion.
The study was conducted in August 2022 and recruited 623 participants online who were sensitive to COVID-19 vaccine topics (e.g., pregnant individuals and their partners). A 2 (message type: expert didactic vs. testimonial) × 3 (background music tempo: none, slow, fast) mixed experimental design was used to systematically compare the behavioral effects of six different video formats. Participants sequentially viewed a COVID-19 vaccine misinformation video followed by an assigned corrective video, and then evaluated the perceived expertise of the video source and their own intentions to engage in misinformation correction and vaccine promotion.
Results showed that, compared to testimonial videos, expert didactic videos significantly increased participants’ intentions to correct misinformation (b = 0.26, 95% CI: 0.06–0.46) and to promote COVID-19 vaccination (b = 0.21, 95% CI: 0.01–0.41). Perceived source expertise served as a key mediating variable in the intervention effects, with indirect effects ranging from 0.04 to 0.07 (p < 0.05). Specifically, perceived expertise fully mediated the effect on vaccine promotion intention and partially mediated the effect on misinformation correction intention. In terms of effect magnitude, exposure to expert videos increased perceived source expertise by 0.36 units (95% CI: 0.10–0.62).
Theoretically, this study reveals the psychological mechanism through which multimodal health correction messages shape behavioral intentions via perceived expertise. Practically, it provides empirical support for the effectiveness of the “whole-of-society” approach in health communication on short video platforms, offering evidence-based insights for public health agencies engaging in new media–based health promotion.
https://doi.org/10.1080/10810730.2025.2503179
03
Safety Analysis of Simultaneous Vaccination of Japanese Encephalitis Attenuated Live Vaccine and Measles, Mumps, and Rubella Combined Attenuated Live Vaccine from 2020 to 2023 in Guangzhou, China
This article, published in Vaccines, employs a retrospective observational study design to systematically evaluate the safety of co-administration of the measles-mumps-rubella combined attenuated live vaccine (MMR) and the Japanese encephalitis attenuated live vaccine (JEV-L) among 8-month-old children in Guangzhou from 2020 to 2023. The study utilized data from the Chinese National Adverse Events Following Immunization Surveillance System (CNAEFIS) and the Guangdong Immunization Information System.
The study included children born after October 1, 2019, who received their first dose of either MMR or JEV-L after June 1, 2020. Using the number of vaccine doses as the denominator, the reporting rates of suspected adverse events following immunization (AEFI) were calculated for three groups (MMR alone, JEV-L alone, and MMR + JEV-L co-administration), and intergroup comparisons were conducted using relative risk (RR).
A total of 799,423 children were included. The numbers of doses administered in the MMR-only, JEV-L-only, and co-administration groups were 241,150; 214,238; and 464,009 respectively, with the co-administration group accounting for 57.98% of total doses. AEFI reporting rates were 60.96 per 100,000 doses (MMR), 11.20 per 100,000 doses (JEV-L), and 53.02 per 100,000 doses (co-administration). Seasonal analysis showed that summer was the peak season for both vaccine administration and AEFI reporting. The most commonly reported adverse reactions were fever and allergic rash, with symptom onset mostly occurring within 24 hours post-vaccination. In all groups, general reactions accounted for the highest proportion of reported AEFIs (all exceeding 87%). In the co-administration group, the reporting rate of high fever (≥38.6°C) was 16.16 per 100,000 doses, significantly higher than that in the JEV-L group (4.20 per 100,000) (RR = 3.85, 95% CI: 1.93–7.68), but not statistically different from that in the MMR group (17.83 per 100,000). Compared with JEV-L alone, the risk of general reactions in the co-administration group was significantly elevated (RR = 4.77, 95% CI: 3.05–7.65), while no statistical difference was found when compared with the MMR group. No significant intergroup differences were observed in local reactions (e.g., erythema and induration) or rare adverse events (e.g., maculopapular rash, urticaria, etc.).
The study indicates that, under real-world vaccination conditions in Guangzhou, the AEFI reporting rate of MMR + JEV-L co-administration lies between those of the two vaccines administered alone, and does not increase the risk of adverse events compared to MMR alone, suggesting that this co-administration strategy demonstrates favorable safety among age-eligible children.
https://doi.org/10.3390/vaccines13040417
04
India’s universal immunization program: A review of successes, challenges, and future directions
This article, published in the Indian Journal of Medical Microbiology, systematically reviews the development trajectory, major achievements, and existing challenges of India’s Universal Immunization Program (UIP) since its implementation in 1978, and offers recommendations for optimization. As a core component of India’s disease prevention system, UIP has expanded from initially covering four vaccines to currently preventing twelve Vaccine-Preventable Diseases (VPDs), including tuberculosis, diphtheria–pertussis–tetanus (DPT), poliomyelitis, measles, rubella, and rotavirus-induced diarrhea.
The study highlights the substantial achievements of UIP: in 2014, India received WHO certification for being “polio-free”; in 2015, it was certified for the “elimination of maternal and neonatal tetanus” at the national level. Since 2014, through Intensified Mission Indradhanush (IMI), UIP has cumulatively delivered immunization services to 546 million children and 132 million pregnant women, reducing the number of “zero-dose” children by 34%. In terms of technological innovation, India successfully developed an indigenously manufactured rotavirus vaccine and pioneered the intradermal administration of inactivated poliovirus vaccine (IPV), significantly reducing vaccination costs. Regarding digital management, the electronic Vaccine Intelligence Network (eVIN), launched in 2015, enabled real-time monitoring of national vaccine inventories and cold chain systems; the U-WIN platform, launched in 2024, is expected to manage immunization records for 30 million pregnant women and 270 million children.
However, UIP continues to face multiple challenges, including instability in the vaccine supply chain, limited manufacturing capacity for key vaccines (such as IPV and Hib), and suboptimal coverage rates for certain vaccines like measles and polio, which hinder the attainment of herd immunity thresholds. Additionally, cross-border virus importation exacerbates the pressure on infectious disease control. Poor data quality and lack of transparency, along with delays in Adverse Events Following Immunization (AEFI) reporting, further undermine the effectiveness of UIP evaluation.
The study recommends optimizing UIP in the following ways: (1) strengthening the vaccine supply chain and enhancing domestic production capacity; (2) improving the performance of immunization information systems, establishing independent evaluation mechanisms, and enhancing data quality and transparency; (3) increasing financial investment to improve the accessibility of immunization services at the primary care level.
https://doi.org/10.1016/j.ijmmb.2025.100854
05
Influenza school-based vaccination: A way to increase equity among children
This article, published in Human Vaccines & Immunotherapeutics, presents a comparative analysis of two influenza vaccination delivery models—health center-based and school-based—implemented in the Region of Murcia, Spain, between 2022 and 2024. The study aims to evaluate the effectiveness of school-based vaccination in increasing overall vaccine coverage and promoting health equity. Based on data from the regional vaccination registry system (VACUSAN), the study adopted a cross-sectional design to compare vaccination coverage rates among children from different birth cohorts (born between 2018 and 2021), focusing specifically on variations associated with parental country of origin and socioeconomic status.
The results indicated that during the 2022–2023 health center-based vaccination campaign, overall coverage rates for 3- and 4-year-old children were 34.8% and 35.4%, respectively. In contrast, during the 2023–2024 school-based campaign, coverage for 3- and 4-year-olds increased to 55.7% and 55.4%, respectively. Meanwhile, 2-year-old children vaccinated at health centers in the 2023–2024 season reached a coverage rate of 43.8%. This increase was statistically significant across all socioeconomic groups and parental origin categories. For example, children with parents from the Eastern Mediterranean region (primarily Morocco) demonstrated the largest increase in coverage, and the most notable improvements were observed among the most socioeconomically disadvantaged group—foreign children without a residence permit (F003). Moreover, among children receiving the same vaccine (live attenuated influenza vaccine, LAIV), those vaccinated at school (3- and 4-year-olds) showed significantly higher coverage rates than 2-year-olds vaccinated at health centers (p < 0.01), with the most pronounced difference observed in the lowest-income group (001), where coverage increased by up to 75%.
The study demonstrates that school-based vaccination programs can effectively enhance influenza vaccine uptake among children, with particularly strong effects among vulnerable populations such as immigrants and low-income groups. These findings provide important evidence to inform public health policy.
https://doi.org/10.1080/21645515.2025.2497207
06
A 14-year influenza reinfection surveillance in Chongqing, China: A retrospective analysis
This article, published in Human Vaccines & Immunotherapeutics, presents a systematic analysis of the epidemiological characteristics and risk factors of influenza reinfection, based on data from the National Notifiable Infectious Disease Reporting Information System (NIDRIS) in Chongqing from 2010 to 2023. Using the Andersen-Gill model, the study analyzed data from 489,526 individuals, accounting for a total of 676,811.47 person-years of observation.
The findings indicate that the cumulative reinfection rate reached 6.11% (29,923 cases), of which 93.56% were single reinfection episodes. The median interval between infections was 9.4 months, with a mean interval of 18.6 months. Reinfection rates increased over time: 5.4% at 12 months, 9.3% at 24 months, 21.5% at 60 months, and 23.9% at 120 months. Analysis of influencing factors revealed that sex, age, occupation, and type of residence were significantly associated with reinfection risk (P < 0.001). Multivariate Cox regression analysis identified male sex, children aged ≤5 years, individuals aged 6–18 years, 46–64 years, ≥65 years, preschool-aged children, and urban residency as independent risk factors for reinfection. In contrast, students and healthcare workers were found to have lower reinfection risk.
The study emphasizes that influenza reinfection is relatively common in Chongqing and exhibits marked differences by age and geographic location. Based on these results, the authors recommend strengthening the following prevention and control measures: (1) increasing influenza vaccination coverage among high-risk groups such as children, older adults, and urban residents; and (2) enhancing influenza surveillance in urban areas to optimize prevention strategies and reduce the disease and economic burden associated with reinfection.
https://doi.org/10.1080/21645515.2025.2497576
Content Editor: Ruitong Li
Page Editor: Ruitong Li
