COVID-19 vaccine boosters from Pfizer Inc (NYSE:PFE) / BioNTech SE (NASDAQ:BNTX) and Moderna Inc (NASDAQ:MRNA) become less effective after four months but still provide significant protection against hospitalization, a CDC study found.
- While vaccine efficacy was still strong two months after a booster shot, it declined significantly after four months.
- Efficacy against COVID-19–associated emergency department visits and hospitalization was 87% and 91%, respectively, during the two months after a third dose and decreased to 66% and 78% by the fourth month after a third dose.
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- Protection against hospitalizations exceeded that against emergency department visits.
- Researchers said the results suggest that additional boosters may be needed.
- "The finding that protection conferred by mRNA vaccines waned in the months after receipt of a third vaccine dose reinforces the importance of further consideration of additional doses to sustain or improve protection against COVID-19–associated ED/UC encounters and COVID-19 hospitalizations," CDC wrote.
- Price Action: MRNA shares are down 12.1% at $141.84, PFE stock is down 2.86% at $49.33, and BNTX shares are down 8.59% at $156.27 during the market session on the last check Monday.
