Nurse Kathe Olmstead prepares a shot that is part of a possible COVID-19 vaccine, developed by the National Institutes of Health and Moderna Inc., in Binghamton, N.Y.
Hans Pennink | AP
The Food and Drug Administration laid out updated safety standards Tuesday for makers of Covid-19 vaccines after the White House blocked their formal release, the latest political tug-of-war between the Trump administration and the government’s public health scientists.
In briefing documents posted on its website, the FDA said vaccine makers should follow trial participants for at least two months to rule out safety issues before seeking emergency approval. That requirement would almost certainly preclude the introduction of a vaccine before Nov. 3.
President Donald Trump has repeatedly insisted a vaccine could be authorized before Election Day, even though top government scientists working on the effort have said that timeline is very unlikely. On Monday Trump said vaccines are coming