Study: Less than 1% of vaccine reactions are reported

Adverse events from drugs and vaccines are common, but underreported. Although 25% of ambulatory patients experience an adverse drug event, less than 0.3% of all adverse drug events and 1-13% of serious events are reported to the Food and Drug Administration (FDA).
Likewise, fewer than 1% of vaccine adverse events are reported. Low reporting rates preclude or slow the identification of “problem” drugs and vaccines that endanger public health.

Read the full Harvard Pilgrim Health Care study, submitted to the U.S. Department of Health and Human Services