There were obvious regional disparities in AEFI surveillance performance, and surveillance training and management should be further strengthened in low-reporting districts to reduce regional gaps and improve overall reporting performance.
Abstract
ABSTRACT Based on the Chinese National Adverse Events Following Immunization Surveillance Information System (CNAEFIS), a descriptive epidemiological analysis was conducted on Adverse Events Following Immunization (AEFI) of National Immunization Program (NIP) vaccines in Shenyang from 2009 to 2024, to understand the distribution characteristics and reporting status of AEFI using passive surveillance data in the region. Reaction types were classified according to national unified surveillance standards. Descriptive epidemiological analysis was carried out from temporal, regional, demographic and vaccine-specific distributions, and AEFI reporting rate was calculated. From 2009 to 2024, a total of 3,420 cases of AEFI associated with NIP vaccines were reported, with an annual average reporting rate of 15.8 per 100,000 doses. Among these, the reporting rate of common vaccine reactions was 14.87 per 100,000, and that of rare vaccine reactions was 0.54 per 100,000. Differences in reporting rates between districts were statistically significant (χ2 = 618.9, p < .05). Most reported events were common reactions, and rare reactions were infrequently reported. There were obvious regional disparities in AEFI surveillance performance. Surveillance training and management should be further strengthened in low-reporting districts to reduce regional gaps and improve overall reporting performance.
Yisheng Jun’an® rabies vaccine exhibits a favorable safety profile with mild-to-moderate reactions, support its use in post-exposure prophylaxis, supporting its use in post-exposure prophylaxis.
Zhijie Cui, Lianfu Wang, Zhiyuan Ran et al.· Frontiers in Public Health· 0 citations
ABSTRACT This study evaluated the impact of immunization schedule adjustment – from a four-dose schedule (3, 4, 5, and 18 months of age) to a five-dose schedule (2, 4, 6, and 18 months of age, and 6y of age) – on the reporting characteristics of adverse events following immunization (AEFIs) with diphtheria, tetanus, and acellular pertussis (DTaP) vaccination in children. Surveillance data in Linping District during 2024 (pre-adjustment) and 2025 (post-adjustment) were collected. Reporting rates, symptom distributions, and dose-specific differences were compared using chi-square tests, rate ratio (RR), and sensitivity analysis. Among 18,869 doses in 2024 (91 AEFIs) and 34,549 doses in 2025 (158 AEFIs), the overall reporting rate of AEFIs did not change significantly (482.27 vs. 457.32 per 100,000 doses; RR = 0.95, 95%CI: 0.83–1.08, P = .442). Local redness and swelling (overall) showed no significant change (RR = 1.04, P = .633), with mild cases (≤2.5 cm) decreasing (RR = 0.20, P = .033) and moderate cases (2.6–5.0 cm) increasing non-significantly (RR = 1.21, P = .138). Local induration (overall) decreased significantly (RR = 0.57, P = .008), driven by moderate induration reduction (2.6–5.0 cm, RR = 0.61, P = .037). The third dose benefited most from the adjustment (RR = 0.40, P < .001). After excluding the fifth dose, reporting rate for doses 1–4 in 2025 was significantly lower than in 2024 (RR = 0.82, P = .006). The fifth dose showed the highest rate (684.84 per 100,000 doses), mostly mild reactions with no serious AEFIs. DTaP schedule adjustment did not increase overall AEFIs rates, while local induration decreased. The primary series (doses 1–4) showed a trend toward improved safety. The newly added fifth dose warrants ongoing monitoring as a key surveillance target.
Tian Liu, Qinghua Chen, Chunmei Ye et al.· Human Vaccines & Immunothera...· 0 citations
Objectives
To describe the distribution and characteristics of adverse events following immunization (AEFI) using a large US pharmacovigilance database.
Methods
A retrospective descriptive analysis of Individual Case Safety Reports (ICSRs) from the FDA AEMS database (January 2017-March 2026) was conducted. Reports were analyzed by vaccine type, adverse event terms, demographics, reporting year, and reporter category.
Results
A total of 2 169 603 ICSRs were identified, with 44.0% classified as serious. COVID-19 vaccines accounted for 78.4% of reports, reflecting mass vaccination campaigns. The most frequently reported events were headache (12.8%), pyrexia (11.8%), and fatigue (11.1%), predominantly non-serious and consistent with known reactogenicity profiles. Reporting peaked in 2021 (48.8%). Females accounted for 60.6% of reports. Non-COVID vaccines contributed substantially fewer reports.
Conclusions
Most vaccine-associated adverse events were mild and expected. Findings support a favorable benefit-risk profile and highlight the importance of continuous pharmacovigilance systems for vaccine safety monitoring.
E. Castellana, MR Chiappetta· Hospital Pharmacy· 0 citations
The adverse events following immunization (AEFI) surveillance programme in India was initially launched in 1986; however, reporting remained sporadic and systematic efforts to streamline the process began only in 2005 with the introduction of the first Operational Guidelines.
To assess the extent of implementation of existing surveillance guidelines in a metropolitan city and to explore the scope for quality improvement.
The study was a Cross-sectional observational record-based study done in the Metropolitan city of Maharashtra. Case reporting form (CRF), preliminary case investigation form (PCIF), and final case investigation form (FCIF) of all cases that occurred from January 2017 to June 2018 were obtained from the concerned authorities. The data obtained from records was compiled and analyzed using Microsoft Excel 2013 and represented using tables.
Out of 129 cases reported, CRFs were available for all cases while PCIFs were available for 118 cases (91.5%). Out of the 116 cases due for FCIF reports, 98 cases (84.5%) had been updated. 23 cases (17.83%) were notified to the health system within 24 h of the occurrence of AEFI, 34 cases (26.36%) were notified between 24 and 48 h and 31 cases (24.03%) were notified between 48 h and 72 h.
Both active and passive surveillance were being followed in the study area. The healthcare workers, including auxiliary nurse midwives and CHVs, conducted home visits of all beneficiaries within 2–3 days postimmunization. This active component of AEFI Surveillance not only improved reporting rates but also helped in early detection and management of adverse events.
S. Simon, Rohan Sangam, Shalini Rawat et al.· Journal of Public Health and...· 0 citations
This report describes influenza surveillance activities in Australia in 2020 to 2021 and the impact which coronavirus disease 2019 (COVID-19) related public health and social measures (PHSMs) had on influenza notifications. Data were extracted from several sources constituting the National Influenza Surveillance Scheme. In 2020 and 2021, a range of PHSMs were instituted across Australia to reduce the spread of COVID-19. These measures had a substantial impact on influenza circulation during this time. Laboratory-confirmed influenza notifications in these years were the lowest reported to the National Notifiable Diseases Surveillance System (NNDSS) since influenza became nationally notifiable in 2001. Laboratory-confirmed influenza notification rates varied greatly between states and territories in the two-year reporting period, likely influenced by differences in the PHSMs instituted across the country. Higher influenza notification rates were observed in the 0-4 and 5-9 year age groups in 2020, while the notification rates in 2021 were very low across all age groups. In 2020, eighty-seven percent of laboratory-confirmed influenza notifications were influenza A (91.1% influenza A(unsubtyped); 7.7% A(H1N1)pdm09; 1.2% A(H3N2)) and 12.6% were influenza B. In 2021, seventy-two percent of laboratory-confirmed influenza notifications were influenza A (91.1% influenza A(unsubtyped); 8.3% A(H3N2); 1.3% A(H1N1)pdm09) and 17.3% were influenza B. Very low influenza activity was also observed in community sentinel surveillance systems. However, slight increases in influenza-like illness, still at very low rates compared to previous years, were reported by sentinel general practices, with rises observed in mid-June in both 2020 and 2021. Very few laboratory-confirmed influenza sentinel hospital admissions and deaths were reported in 2020 and 2021.
S. Whitehead, Jenna Hassall, Lauren Kutzner et al.· Communicable diseases intell...· 0 citations
To stabilize the situation, critical measures include: implementation of booster vaccination for school-aged children; mandatory maternal immunization to provide transplacental protection to newborns; and strict adherence to completion of vaccination series for children following pertussis infection.
A. V. Prokopenko, A. V. Lomonosova, A. I. Dzhepko· Epidemiology and Vaccinal Pr...· 0 citations