Pfizer Says Late-Stage Coronavirus Vaccine Study Shows Mild, Moderate Side Effects

Meanwhile, British rival AstraZeneca's trials are on hold.

(Reuters) ― Pfizer Inc. said on Tuesday participants were showing mild-to-moderate side effects when given either the company’s experimental coronavirus vaccine or a placebo in an ongoing late-stage study.

Over 12,000 study participants had received a second dose of the vaccine, Pfizer executives said on an investor conference call.

The company has enrolled more than 29,000 people in its 44,000-volunteer trial to test the experimental COVID-19 vaccine it is developing with German partner BioNTech.

Pfizer said it was continuously scrutinizing the safety and tolerability of the vaccine in its study.

An independent data monitoring committee could recommend pausing the study at any time, but has not done so till date, the company said.

The comments follow rival AstraZeneca’s COVID-19 vaccine trials being put on hold worldwide on Sept. 6 after a serious side effect was reported in a volunteer in Britain.

AstraZeneca’s trials resumed in Britain and Brazil on Monday following the green light from British regulators, but remain on hold in the United States.

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