Adverse events following immunisation (AEFI) reports from the Zimbabwe expanded programme on immunisation (ZEPI): an analysis of spontaneous reports in Vigibase from 1997 to 2017
More than one in ten vaccine-related adverse events in Zimbabwe are serious (11%), and measles-containing vaccines are one of the vaccines most frequently responsible for serious and systemic reactions.
The authors examined passively collected reports of adverse events following immunization (AEFI) in Zimbabwe from 1997 to 2017. Given widespread underreporting to the country’s still-developing vaccine surveillance system, just 272 Individual Case Safety Reports (ICSRs) were available, of which 11% represented “serious events.” Of these, 6% were deaths and 5% were life-threatening or involved prolonged hospitalization. Measles-containing vaccines had the highest AEFI reporting rate and were also strongly associated with serious events, as was a six-component vaccine containing antigens for oral poliovirus, diphtheria, tetanus, pertussis, Haemophilus influenzae type b and hepatitis B (OPV/DTP-Hib-HepB). The majority of AEFI were systemic (versus vaccine site reactions)—and systemic events, again, were associated with measles-containing vaccines.