Pfizer Says COVID-19 Vaccine Only Showed Moderate Side-Effects In Initial Late-Stage Trials

Pfizer Inc PFE on Tuesday said only mild-to-moderate side effects were observed in volunteers administered with its COVID-19 vaccine in late-stage human trials.

What Happened: The ongoing Phase 3 trials were carried out in such a way that 50% of the participants received its BNT162b2 vaccine candidate and the rest a placebo, the company said in a statement.

The New York-based drugmaker is seeking approval from the United States Food and Drug Administration to expand its late-stage coronavirus vaccine study to 44,000 participants from the original 30,000.

Microsoft Corporation MSFT co-founder Bill Gates, whose foundation has donated millions to Pfizer for the development of a COVID-19 vaccine, and is also supporting efforts of other life science companies, thinks none of the vaccines are likely to seek approval in the U.S. before October, CNBC reported.

“The only vaccine that if everything went perfectly, might seek the emergency use license by the end of October, would be Pfizer,” Gates said.

Why It Matters: Pfizer CEO Albert Bourla said the company’s vaccine, made in partnership with BioNTech SE BNTX, could be distributed in the U.S. before the year-end, if found safe, CNBC noted.

The Centers for Disease Control and Prevention asked all 50 states earlier this month to be prepared to distribute two vaccines in late October or November. These vaccines are thought to be the candidates of Moderna Inc MRNA and Pfizer, according to the New York Times.

Price Action: Pfizer shares closed almost 0.1% lower at $36.96 on Tuesday and gained 0.24% in the after-hours session. On the same day, BioNTech shares closed almost 0.8% lower at $66.92 and gained 0.1% in the after-hours session.