Deaths after Seasonal Influenza Vaccination under Surveillance of Adverse Events Following Immunization in Thailand, 2008 – 2013

Abstract

The Ministry of Public Health Thailand had introduced seasonal influenza vaccine since 2009 as a policy for preventing people from influenza disease outbreak. The high risk group prone to serious complications is considered to be target of seasonal influenza vaccine campaign. This includes health care workers, elderly, young children, pregnant women and people with certain health conditions such as diabetes, lung or heart diseases. Therefore, passive surveillance on adverse events following seasonal influenza vaccine has been operated under routine surveillance on adverse events following immunization (AEFI) by Bureau of Epidemiology for monitoring adverse events, especially in serious cases or deaths. Since 2009 - 2013, 49 deaths were reported, with the highest among people with underlying heart diseases (32.10%). Causality assessment done by AEFI Expert Review Committee illustrated 47 deaths that were not related to the vaccine and major cause indicated to their underlying chronic diseases (65.96%). Cause of last 2 deaths was due to possible vaccine reaction with demonstration of Guillain Barre Syndrome (GBS) and suspected anaphylaxis. The Committee suggested important points to reduce deaths by improving vaccine administration, emphasizing on screening before vaccination. People with uncontrolled chronic diseases should be examined by doctor before vaccination.