Covid Vaccine Candidates Have No Known Serious Side Effects, Says Operation Warp Speed Head

Author image

Jemima McEvoy   Forbes U.S. Staff

Covid Vaccine Candidates Have No Known Serious Side Effects, Says Operation Warp Speed Head

With polling showing some Americans lack of confidence in the safety of coronavirus vaccines that are on the verge of being approved, the head of the White House’s program to accelerate vaccine development, Operation Warp Speed, said Sunday that his team knows the side effects of both candidates currently under consideration and is “very confident” that they are both effective and safe in the long-term.


- “There are no serious adverse side effects associated with these vaccines to the best of our understanding,” Operation Warp Speed Chief Moncef Slaoui told CBS’ Face the Nation on Sunday morning. 

- Slaoui said that the Moderna and Pfizer-BioNTech vaccines have been tested on over 70,000 people, meaning that the federal government has a “good understanding” of the side effects that come within six months.

- The primary side effect of the vaccine is a “significant, not overwhelmingly,  but significant pain” and “redness” at the injection site, which occurs in about 10 or 15% of people, said Slaoui, adding that it “can be treated with Advil or Tylenol.” 

- Some administered the vaccine also experienced “a little bit of fever and chills,” per the Operation Warp Speed chief, but those impacts also disappear within 24 to 36 hours. 

- Slaoui said that his team can be confident in the long-term safety of these vaccines because the most serious adverse effects of vaccines typically occur soon after they are administered. 


“We know from the hundreds of thousands of subjects that have been studied with other vaccines over the past 30 or 40 years, that most serious adverse events with vaccines happen within, let's say, a month and a half to two months after people completed their immunization,” said Slaoui, who previously served as the head of GlaxoSmithKline’s vaccines department. “We have that observation with these vaccines, there are no such serious side effects” 


Public confidence in the vaccine appears to be on the rise. In September, a Gallup poll found that 50% of those surveyed said they would not take the vaccine. The number has decreased in the months that followed, with a survey of public opinion during the period of Oct. 19 through Nov. 1 showing just 42% of Americans said they wouldn’t take the injection. A Pew Research Center poll released around the same time offered a less rosy prediction of just 51% of adults indicating willingness to take the antidote. 


Both vaccine candidates are currently under review by the Food and Drug Administration. Health and Human Services Secretary Alex Azar suggested that approval may be imminent, saying Sunday that he expects authorization to come “within days.” Slaoui said that he’s anticipating a “positive decision” from the FDA based on the data he’s seen. 

Author image

Jemima McEvoy   Forbes U.S. Staff

I'm a British-born reporter covering breaking news for Forbes.