NEW YORK: Pfizer Inc on Tuesday updated its analysis of the safety profile of its COVID-19 vaccine seen during its large, late-stage trial, saying that 3.8% of participants experienced fatigue after receiving a second dose of the shot.

It said the updated analysis was based on 8,000 trial participants. Pfizer said in a previous analysis that 3.7% of 6,000 volunteers had experienced fatigue.

Pfizer also added that there was a second adverse event with a frequency of at least 2% in the trial. The US drugmaker said 2% of participants experienced headaches after the second shot.