Last week, I met my sister and her friend for a walk around a lake in the spring weather. As we chatted, I learned that her friend has been skeptical — like many — about getting a COVID-19 vaccine.
Because she knows that I’m an infectious disease specialist, she had a lot of good questions for me. For one thing, she wanted to know about the safety of vaccines that use genetic material. This is far from the first time I’ve been asked these questions. Because most people have never had this kind of vaccine before, they are nervous and confused about what exactly this vaccine does.
I told her what I tell everyone: These vaccines are safe. But if you’re still nervous, there are vaccines on the horizon that don’t use the same technology.
Here’s how I answer common questions about the COVID-19 vaccines:
Most people are getting the Pfizer or the Moderna vaccines, which use genetic technology. Will they change my DNA?
You’re right that the Pfizer and Moderna vaccines use genetic technology and are messenger ribonucleic acid (mRNA) vaccines. mRNA provides instructions to your cells to make certain proteins. But interestingly, this technology was studied to protect against other infections, including Ebola and other coronaviruses, long before there was even an illness called COVID-19. This is partially why these vaccines could be so quickly developed to protect against the COVID-19 virus.
A lot of people are worried that because these vaccines use genetic technology, they might have long-term side effects or even change genes. But that’s not how these vaccines work. These vaccines are made up of a tiny piece of mRNA that triggers your own cells to make the spike protein of the virus that causes COVID-19. This protein provokes an immune response and gets your immune system ready to respond if the COVID-19 virus and its spike protein enter your body.
The mRNA in the vaccine is fragile and cleared from your body quickly. It does not get close to your genes. The protein that your cells make in response to the vaccine is cleared over a few weeks and appears to stay close to the site of the vaccination — such as in your arm.
How safe are COVID vaccines?
These vaccines are very safe. Like other vaccines, a sore arm and brief flu-like symptoms of fever, fatigue, muscle aches and headache can occur. Some people get an enlarged lymph node for a few weeks under the arm. Rarely, people can have a serious allergic reaction, similar to what can rarely occur with other vaccinations. Inflammation of the heart muscle (myocarditis) has occurred after these vaccines but is generally mild and is also seen in people who have COVID-19. The inflammation of the heart that can occur with COVID-19 can be severe and even life-threatening. Overall, people are much more likely to get seriously ill from having COVID-19 than from getting vaccinated.
Because of misinformation on social media, many people are worried that the vaccines will affect their fertility. There is no evidence that this occurs, and when looking at how the mRNA vaccines work, it does not seem logical to expect an effect on fertility.
These vaccines are safe for everyone — including pregnant women. All who can get vaccinated should get vaccinated.
Is one COVID vaccine better than the other?
This is a more challenging question to answer since researchers keep learning more about how long the protection from the vaccines lasts. The Moderna vaccine contains a larger dose of mRNA than the Pfizer vaccine. Nonserious side effects, such as flu-like symptoms, are apparently more common with the Moderna vaccine. Some preliminary evidence also indicates that the Moderna vaccine may trigger immunity that lasts longer than the immunity from the Pfizer vaccine. However, both of these vaccines provide great protection against getting seriously ill with COVID-19.
I’m not convinced. I don’t want to get any vaccine that has anything to do with genetic stuff. Is there another option?
You’re not alone. Other people are leery of getting COVID-19 vaccines because of what they have read or because the science behind the current vaccines is complicated. Some people have just decided they don’t want to take any of the current vaccines.
The good news is that there may soon be a vaccine that uses more-standard vaccine technology. Two vaccines made by different companies — Novavax and Sanofi-GlaxoSmithKline — are protein vaccines. The vaccines for whooping cough and hepatitis B are examples of protein vaccines that many people have had in the past.
For the Novavax and Sanofi-GlaxoSmithKline COVID-19 vaccines, the spike protein of the virus that causes COVID-19 is grown in the laboratory in moth cells. The protein is purified and then assembled into particles that are designed to mimic the structure of the virus that causes COVID-19. It is then injected with a substance (adjuvant) known to increase the immune response. These proteins do not cause disease but will elicit an immune response. Currently the vaccines are planned as two doses.
Novavax has submitted its COVID-19 vaccine for emergency use to the FDA, and Sanofi-GlaxoSmithKline has stated it will seek authorization for its COVID-19 vaccine.
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