“Proving that a vaccine works is easier than proving that it’s safe,” former US Centers for Disease Control and Prevention Director Dr. Tom Frieden said Tuesday.
During an event hosted by the Infectious Diseases Society of America,Frieden said he has two safety concerns regarding a potential Covid-19 vaccine.
“First are the Kawasaki-like syndrome and illnesses that we’ve seen in children, and possibly similar illnesses in adults,” Frieden said. “That is an immune reaction, and therefore there’s a theoretical chance that some vaccines could create that kind of reaction.”
Frieden, who is currently president and CEO of the global health initiative Resolve to Save Lives, emphasized that he is not predicting this will happen, but suggesting that we do due diligence in watching out for it.
“The second concern is sometimes called antibody-dependent enhancement,” Frieden said. “This has been seen in some old vaccines, half a century ago, but it also was seen in an animal model of one SARS vaccine.”
“The risk there would be some people – after vaccination, if they then became infected with Covid – could get sicker then they would have otherwise,” he explained.
Frieden said that we likely will not know everything we need to about vaccines until they are given to thousands, or maybe even millions of people.
“But we need to track safety at every step of the way and be completely open with the public about it,” he said.