Fainting after Johnson & Johnson COVID-19 vaccination 164 times more common than post-flu shot: CDC

Prior to reports of rare but serious blood clotting with Johnson & Johnson’s COVID-19 vaccine, federal health authorities were investigating dozens of anxiety-related events and fainting episodes in vaccine recipients, according to the latest report from the Centers for Disease Control and Prevention (CDC).

"[Four of five] sites providing drive-through vaccination had previously administered 1,000–4,000 mRNA COVID-19 vaccines per day without reported similar clusters of events," CDC researchers wrote. When comparing anxiety-related events with the flu vaccine, CDC researchers noted fainting episodes were reported at a rate of 0.05 per 100,000 doses, compared to 8.2 fainting episodes per 100,000 J&J doses. The flu vaccine was used as a comparison because both are single-dose vaccines and available to all U.S. adults, compared to the two-dose mRNA COVID-19 vaccines which were rolled out among higher-tiered prioritization groups, while J&J entered the national rollout later on.