We do not know if the Pfizer/BioNTech vaccine is safe or effective after two months. The emergency use authorization was given because it “may be effective in preventing COVID.” "Unfavorable new preclinical or clinical trial data” may cause “actual results to differ materially” from Pfizer's current statements about their vaccine.

In Pfizer’s FDA briefing document, there are many unknowns:

– duration of protection

– effectiveness in high-risk populations

– individuals with prior infection

– effectiveness in pediatric populations

– effectiveness against mortality

– adverse reactions after two months

– vaccine-enhanced disease as immunity wanes

Over 20,000 people received saline injections (placebo), and only 162 developed COVID, 95% of the infections were mild symptoms. Only 4 had severe disease requiring hospitalization (compared to 1 in the vaccine group). These are remarkable results – a hospitalization rate of 0.018, and no deaths, without the vaccine.

Changes in the virus/pandemic may "limit the generalizability of the efficacy conclusions over time.” If health care workers are at higher risk of severe infection as immunity wanes, the vaccine may make the current situation much worse.

Robert Hagar

New London