Pfizer Reports Mild to Moderate Side Effects in COVID-19 Vaccine Trial Participants

　　Pfizer Inc.: Mild to Moderate Side Effects Observed in Vaccine Clinical Trial Participants

Pfizer, the U.S. pharmaceutical company, announced on the 15th that participants in its COVID-19 vaccine clinical trials experienced mild to moderate side effects.

According to a Reuters report on the 16th, Pfizer disclosed this information at an investor conference on the 15th. Side effects reported by trial participants included fatigue, headache, chills, and muscle pain, with some individuals experiencing fever, including high fever. These data were derived from a double-blind trial, meaning that Pfizer did not know which participants had received the vaccine and which had received the placebo.

According to a Bloomberg report on the 16th, Mikael Dolsten, Chief Scientific Officer of Pfizer, stated at an investor conference that no safety issues have been reported in Pfizer’s vaccine trials so far. Pfizer indicated that fatigue has been the most common side effect observed in the trials to date.

Pfizer’s vaccine, developed in collaboration with Germany’s BioNTech, is planned for clinical trials involving 44,000 volunteers. To date, more than 29,000 participants have been enrolled, and over 12,000 volunteers have received the second dose. Pfizer expects to obtain experimental results on the vaccine’s efficacy by October.

On September 8, British pharmaceutical company AstraZeneca announced that a volunteer in the vaccine trial it was developing in collaboration with the University of Oxford had developed an “unexplained” illness, leading to the suspension of the trial. According to Reuters, the vaccine trial resumed in the UK and Brazil on the 14th, but remains paused in the United States.