Barriers to healthcare workers reporting adverse events following immunization in four regions of Ghana.

Despite didactic training on adverse events following immunization (AEFI) in Ghana, the reporting ratio of AEFI was 1.56 per 100,000 surviving infants in 2015, below the minimum reporting ratio of 10. We aimed to estimate the proportion of health care workers (HCWs) reporting AEFI and to identify barriers to reporting.