(Reuters) – Pfizer Inc. PFE.N On Tuesday, participants said that there were either mild-to-moderate side effects seen in the company’s experimental coronavirus vaccine or a late-stage study running in placebo.
The company said in a presentation to investors that side effects include fatigue, headaches, chills and muscle aches. Some participants in the trial also developed fever – including some high fever. The data have been blinded, meaning that Pfizer does not know which patients have received the vaccine or placebo.
Pfizer’s head of vaccine research and development, Catherine Janssen, insisted that the independent data monitoring committee “does not have access to the data so that they inform us that they have any security concerns and have not done so to date.”
The company has enrolled more than 29,000 people in its 44,000-volunteer trial, developing it with German partner BioNTech to test the experimental COVID-19 vaccine. 22UAy.F.
More than 12,000 study participants had received a second dose of the vaccine, Pfizer officials said on an investor conference call.
Comments are of rival AstraZeneca AZN.L COVID-19 vaccine trials are being conducted worldwide on 6 September after a volunteer in the UK reported serious side effects.
AstraZeneca’s trial resumed in the UK and Brazil on Monday following a green light from British regulators, but remained on hold in the United States.
Pfizer expects the results to be in place as to whether the vaccine works in October.
“We believe – also very strong immune profile and preclinical profile … that vaccine efficacy is likely to be 60% or more,” said Pfizer’s chief scientific officer, Mikel Dolston.
Reporting by Manas Mishra in Bengaluru and mIchael Erman in Maplewood, NJ; Editing by Arun Kayur, Shaunak Dasgupta and Arora Ellis