Q: This vaccine has never been used in humans. How do we know it’s safe?
The Pfizer phase 3 trial included more than 43,000 people, and Moderna’s had more than 30,000. The first humans received mRNA-based COVID-19 vaccines in March. The most common adverse events emerge right after a vaccination, Dr. Kuppalli said.
As with any vaccine that gains approval, monitoring will continue.
UK health officials have reported that two health care workers vaccinated in the initial rollout of the Pfizer vaccine had what seems to have been a severe allergic response. Both recipients had a history of anaphylactic allergic responses and carried EpiPens, and both recovered. During the trial, allergic reaction rates were 0.63% in the vaccine group and 0.51% in the placebo group.
As a result of the two reactions, UK regulators are now recommending that patients with a history of severe allergies not receive the vaccine at the current time.
Q: What are the likely side effects?
So far, the most common side effects are pain at the injection site and an achy, flu-like feeling, Dr. Kuppalli said. More severe reactions have been reported, but were not common in the trials.
Dr. Rasmussen noted that the common side effects are a good sign, and signal that the recipient is generating “a robust immune response.”
“Everybody I’ve talked to who’s had the response has said they would go through it again,” Dr. Kruppalli said. “I definitely plan on lining up and being one of the first people to get the vaccine.”
Q: I already had COVID-19 or had a positive antibody test. Do I still need to get the vaccine?
Dr. Rasmussen said that there are “too many unknowns” to say if a history of COVID-19 would make a difference. “We don’t know how long neutralizing antibodies last” after infection, she said. “What we know is that the vaccine tends to produce antibody titers towards the higher end of the spectrum,” suggesting better immunity with vaccination than after natural infection.
Q: Can patients of color feel safe getting the vaccine?
“People of color might be understandably reluctant to take a vaccine that was developed in a way that appears to be faster [than past development],” said Dr. Rasmussen. She said physicians should acknowledge and understand the history that has led them to feel that way, “everything from Tuskegee to Henrietta Lacks to today.”
Empathy is key, and “providers should meet patients where they are and not condescend to them.”
Dr. Kuppalli agreed. “Clinicians really need to work on trying to strip away their biases.”
Thus far there are no safety signals that differ by race or ethnicity, according to the companies. The Pfizer phase 3 trial enrolled just over 9% Black participants, 0.5% Native American/Alaska Native, 0.2% Native Hawaiian/Pacific Islander, 2.3% multiracial participants, and 28% Hispanic/Latinx. For its part, Moderna says that approximately 37% of participants in its phase 3 trial come from communities of color.
Q: What about children and pregnant women?
Although the trials included participants from many different age groups and backgrounds, children and pregnant or lactating women were not among them. Pfizer gained approval in October to include participants as young as age 12 years, and a Moderna spokesperson said in an interview that the company planned pediatric inclusion at the end of 2020, pending approval.
“Unfortunately, we don’t have data on pregnant and lactating women,” Dr. Kuppalli said. She said she hopes that public health organizations such as the CDC will address that in the coming weeks. Dr. Rasmussen called the lack of data in pregnant women and children “a big oversight.”
Dr. Rasmussen has disclosed no relevant financial relationships. Dr. Kuppalli is a consultant with GlaxoSmithKline.
A version of this article originally appeared on Medscape.com.