‘Monitoring of adverse events after immunisation improved in TN’

CHENNAI: While immunisation for various illnesses is being emphasised by the State Health Department, the monitoring of Adverse Events Following Immunisation (AEFI) has also been intensified over the last 10 years.

A study titled ‘Surveillance of Adverse Events Following Immunization following routine Immunisation in Tamil Nadu’ was published in the Tamil Nadu Journal of Public Health and Medical Research.

While minor AEFI reported in the State were 2,671 in 2011-12, it has increased to 46,369 in 2023-24. The approximate vaccine doses administered was 95.56 lakhs in 2011-12 and increased to 146.42 lakhs in 2023-24.

The study states that when novel vaccinations or vaccine combination products are introduced, monitoring AEFI is crucial. AEFIs must be properly identified, reported, and handled. Even if they are moderate, and resolve on their own without requiring longterm care, extremely uncommon cases might result in substantial adverse reactions. Every time a vaccine is administered, the risk of AEFI is balanced against the danger of not immunising a child.

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 reporting of AEFI in 2020, and 2021, mainly due to the pandemic.

Around 89.3% of the serious and severe AEFI cases reported since 2015 were discussed, 47.8% of cases were found to be vaccine-related reactions, while 39.3% were coincidental events and there were no cases due to vaccine quality defect related reactions.

The Director of Public Health and Preventive Medicine, Dr TS Selvavinayagam, explained, “Trainings, increasing awareness among field level staff, and monitoring should be done consistently to further improve AEFI surveillance in the State.”

Every time a vaccine is administered, the risk of AEFI is balanced against the danger of not immunising a child