INTRODUCTION : Globally, 3.5- 5 million childhood deaths are averted every year and more than 15 million future deaths have been halved with increasing access to immunisation services. Vaccines are safe, but it’s a fact that no vaccination is risk-free, and after vaccination, side effects may occur in some instances. A vaccine may naturally result in fever, erythema, localized discomfort, etc. during the immunity-building process. There is a remote chance that the vaccine's ingredients will cause a foreign body reaction, which may raise some concerns to parents and caregivers. Monitoring of Adverse Events Following Immunization (AEFI) is an essential strategy for ensuring the safety of vaccines. This article describes status of implementation, key aspects and challenges of AEFI Surveillance in Tamil Nadu. The program documents from 2008, minutes of AEFI committee meetings and all cases discussed in each of the meetings were analysed.
Minor AEFI reported in the state HMIS portal is 2,671 in 2011-12 and is 46,369 in 2023-24. The approximate vaccine doses administered is 95.56 and 146.42 Lakhs in in 2011-12 and 2023-24 respectively. The number of reported serious and severe AEFI cases increased from 92 in 2015 to 457 AEFIs in 2023. However, there was a slight reduction in AEFI reporting seen in 2020, 2021 which may be due to COVID-19 pandemic. Annual reporting ratio of AEFI per 100,000 surviving infants, designated as a performance indicator is 0.71 in 2015-16 and 4.71 in 2023-24. Of total 1,887 serious and severe AEFI cases reported from the year 2015, 1,684(89.3%) has been discussed and of those, 47.8% of AEFIs were classified as ‘A1’- Vaccine product related reactions, 39.3% as ‘C’- Coincidental events and there were Zero% of AEFIs due to “A2”- Vaccine quality defect related reactions.
Trainings, increasing awareness among field level staff, and monitoring should be done consistently to further improve AEFI surveillance in the State. Embracing future research opportunities in AEFI including descriptive analysis, and qualitative study among field workers can indeed help stakeholders enhance the effectiveness and transparency of AEFI surveillance systems. This in turn contribute significantly to maintain public confidence in vaccination programs and ensuring vaccine safety for all populations.