Straight answers to common questions about COVID-19 vaccines

By Michael Merschel, American Heart Association News

Jasmin Merdan/Moment, Getty Images
(Jasmin Merdan/Moment, Getty Images)

If you've got questions about COVID-19 vaccines, you're not the only one. Even as many people rush to get their shots, surveys show others just aren't sure about them.

Dr. Won Lee, medical director of Boston Medical Center's Home Care Program, understands. "There's so much misinformation out there," she said. "And it's hard for anyone to know what to believe."

Lee is part of a medical team that helps elderly homebound people. She's heard lots of concerns firsthand.

So has Heneliaka Jones, a registered nurse in the Positive Health Program at Zuckerberg San Francisco General Hospital. Many of the people she encounters are in underserved groups or are marginally housed. They distrust the health care system in general and have specific concerns about the vaccine. She respects that.

"Regardless of your background, people want to know the truth," she said.

Can I trust these vaccines?

Early on, Lee heard a lot of comments along the lines of, "'I think I want it, but I don't know if I want to be the first one to get it."

Many of the patients she sees have conditions such as heart failure, diabetes or dementia. People worry the vaccines weren't tested thoroughly. Family members would say, "I would like my aunt or my grandma to get the vaccine, but I haven't heard of any other 86-year-olds getting it yet."

Lee said the vaccines available in the United States were, indeed, studied thoroughly, including in older adults, and found to be safe and effective. (The Centers for Disease Control and Prevention and Food and Drug Administration post details about the process and each vaccine's results.)

People living in nursing homes were among the first wave of people to be vaccinated. She tells her patients and their families: "Folks in nursing homes tend to be very frail, with a lot of medical issues needing a lot of help day to day. So if they're able to get it, and they tolerated it with not a lot of side effects, then it's safe for you, too."

On Tuesday, the CDC and FDA called for an immediate pause "out of an abundance of caution" in use of the single-shot Johnson & Johnson vaccine after rare clotting cases. This demonstrates that federal health agencies continue to monitor for possible problems and respond accordingly. Experts said early on that rare complications would not be unusual as the vaccines are rolled out to hundreds of millions of people.

Weren't the vaccines made in a rush?

While many people celebrate the global effort that produced the vaccines, the speed with which they came out makes others worry. They question official reassurances that no corners were cut.

But Jones said, "When the whole world shuts down like this, money is going to be available, and time is going to be available."

Bureaucracies streamlined, scientists worked long hours and manufacturers coordinated on production and distribution.

Amid all that, the three vaccines currently available in the U.S. were each rigorously tested in tens of thousands of people from all backgrounds with diverse characteristics. Research shows the vaccines protect people from getting COVID-19, and even among those who do become infected, vaccination prevents serious illness.

Isn't the technology untested? Will it do long-term damage to my DNA, or make me spread COVID-19?

When the vaccines were new, Jones heard people say, "I've seen this in scary movies. You guys are gonna turn into zombies!"

People also have serious concerns about the technology or worry the vaccine will load them up with the virus.

Jones explains the vaccines work by showing cells how to make a harmless version of the "spike protein" found on the surface of the virus that causes COVID-19. A vaccine basically offers an instruction manual that teaches your cells to recognize and fight the virus.

The Pfizer and Moderna vaccines use what's called messenger RNA, or mRNA. It's a new type of vaccine, but it's a well-studied technology scientists have been working on for years. Johnson & Johnson's is a "viral vector" vaccine. It uses a harmless, disabled virus to deliver the instructions for making the spike protein.

The vaccines do not interact with your DNA in any way, Lee said. They contain no live virus. "You will not get COVID from this vaccine."

I'm worried about side effects.

Minor side effects such as fatigue and headache are real. "That's actually your body fighting against something that doesn't belong," building your defenses against the real virus, she said. "You feel bad when it's happening. But it's a good thing that you know it is happening."

For every million people vaccinated, approximately two to five people will have a severe allergic reaction called anaphylaxis, according to the CDC. That can be treated easily and occurs within minutes of the shot being given, and it's why vaccine providers have people wait nearby after inoculation.

Tuesday's recommended pause of the Johnson & Johnson vaccine will allow scientists to review the data on six women who developed a rare disorder involving blood clots within one to two weeks after receiving the vaccine. As of Monday, more than 6.8 million doses had been administered in the U.S.

"Right now, these adverse events appear to be extremely rare," Dr. Anne Schuchat, principal deputy director of the CDC, and Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said in a joint statement. "COVID-19 vaccine safety is a top priority for the federal government, and we take all reports of health problems following COVID-19 vaccination very seriously."

The government continues to track how people react to the vaccines, and other rare side effects could show up. But Lee tells her families she got the vaccine. It was an easy decision.

"Risking side effects from the vaccine is nothing compared to the risk of death and suffering from COVID."

Do I really need it?

Getting vaccinated will help end the pandemic for everyone, Jones said.

"When people say to me, 'Why should I get it?' I just say, 'Think of it as a messy house. Sure, you can clean up the house all by yourself, but if you invite friends over, it can get cleaned up much faster.'"

Vaccines also help bring back things the virus took away, such as visits with grandparents, time with friends or breaks for worn-out caregivers, Lee said. She finds it "super exciting" that her elderly patients can head back to community centers. "A lot of these programs are lifelines of socialization and connectedness."

Younger family members are going back to work or school, Lee said. "That return to some element of normalcy, I think, is what we all need."

What if I still have questions?

Ask a medical professional you trust, Lee said.

"There are no bad questions," she said. The information can be overwhelming, and the concerns can be deeply personal. "Just reach out. And don't wait for someone to call you. Just be proactive, ask those questions, and try to get more information that will help you make informed decision."

Editor's note: Because of the rapidly evolving events surrounding the coronavirus, the facts and advice presented in this story may have changed since publication. Visit for the latest coverage, and check with the Centers for Disease Control and Prevention and local health officials for the most recent guidance.

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