DC-area expert answers questions about COVID-19 vaccine

As the rollout of COVID-19 vaccines slowly proceeds, questions persist among the unvaccinated.

And on Tuesday, Dr. Glenn Wortmann, a MedStar Health infectious disease specialist, answered some of those questions on Facebook Live. His answers are below.

If you’re about 50% protected after a first shot of each available COVID-19 vaccine, why is the second dose so important?

“You’re about 50% protected for probably a short period of time, but you won’t have 95% protection for a long period of time,” Wortmann said. “So, you have to come back on day 21 for Pfizer-BioNTech or day 28 for Moderna to get that boost. It’s critical; you have to get both doses,” Wortmann said.

If you’re vaccinated, do you still need to wear a mask?

Yes, for two reasons. First, vaccines aren’t 100% effective. Second is the scientific unknown. The coronavirus infects someone when it moves from their nose into the rest of their system. Vaccination can prevent that spread, but it’s unknown how long the virus can live in someone’s nose to potentially be transmitted.

“There are studies going on right now … and they’re measuring to see if you got the vaccine, does that mean the virus can’t live in your nose for a couple days? We just don’t know the answer,” Wortmann said. “We just don’t know if you can be a carrier and how long you can be a carrier. And, so that’s why we’re recommending the masks and social distancing for now. And as those studies come out, and we’re all praying that it’s going to show we don’t carry, then we may be able to drop the masking down the road.”

If the vaccines are said to be about 95% effective, is there a way to know whether you’re among the 5% or so not protected?

“There’s no antibody test or other test that you can do to see, ‘Is the vaccine working for me?’ — like we can do with hepatitis B,” Wortmann said. “We don’t have that type of test for the COVID-19 vaccine. Hopefully one will come down the road, but right now it’s not available.”

If you’ve had COVID-19 should you still get vaccinated?

Yes. Available data show you’re probably protected against reinfection for at least three months and maybe for as long as six months or somewhere in between.

“But long-term protection from natural infection probably isn’t there,” Wortmann said. “What we are planning is that the vaccine would give you long-term protection. We don’t know how long yet, but hopefully for a year or two before we would need our booster shot.”

What are we learning about the likelihood of experiencing an allergic reaction?

Both vaccines were approved for use after studies that involved 30,000 to 40,000 subjects. Now, 10 million to 11 million people are enrolled.

“We’re getting a better idea of how common is this allergic reaction, and it’s not that common. It’s turning out to be about one in 100,000 who get vaccinated,” Wortmann said. “And to put that in perspective, the risk of an allergic reaction to penicillin is one in 5,000.”

So, while Wortmann said the risk of an allergic reaction to the COVID-19 shot is real, “It’s very, very, very uncommon.”

More Coronavirus news

Looking for more information? D.C., Maryland and Virginia are each releasing more data every day. Visit their official sites here: Virginia | Maryland | D.C.

More from WTOP

Log in to your WTOP account for notifications and alerts customized for you.

Sign up