10 Covid-19 Vaccine Myths No One Should Fall For

Can Covid-19 vaccines cause sterilization or infertility, alter your DNA, or give you the virus? Covid-19 vaccine myths are running rampant, so we asked health experts to separate fact from fiction.

Covid-19 vaccine myths

People all over the country are waiting in line, sleeves rolled up, to get one of the three Covid-19 vaccines, developed by Pfizer-BioNTech, Moderna, and Johnson & Johnson. Unfortunately, others aren’t so eager.

The Kaiser Family Foundation reported in February that 22 percent of Americans still weren’t ready for a jab. The gap between Americans who will and won’t get the vaccine is shrinking, but it needs to shrink further, especially with troubling variants now circulating.

The only way to reach herd immunity is to get 80 to 85 percent or more of the population vaccinated.

“Now is not the time to ponder whether you want to get the vaccine,” says Kathryn M. Edwards, MD, scientific director of the Vanderbilt University Vaccine Research Program in Nashville. “We need as many people as we can to reduce transmission and really get the cycle turned down,” she says.

As vaccine processing and distribution continues, and more and more people are able to get vaccinated, it’s important to separate fact from fiction when it comes to Covid-19 vaccines. (Here are the coronavirus myths you should stop believing.)

We spoke with experts to set the record straight on these Covid-19 vaccine myths.

Myth: The vaccine makes you infertile

This lie arose because someone noticed that the Covid-19 spike protein (part of the virus that plays a role in how the virus infects us) and a protein in human placenta look alike.

Because two of the vaccines—Moderna’s and Pfizer-BioNTech’s—target the spike protein, they’ll harm the placenta and make you sterile, right? Wrong.

“There is no evidence that the vaccine can lead to loss of fertility,” reads a joint statement from three leading reproductive-health organizations. The two proteins are, in fact, totally different. The Covid-19 vaccine does not lead to sterilization.

On the other hand, getting Covid-19—the disease, not the vaccine—could endanger a pregnancy.

“There have been some reports that if pregnant women get Covid-19, they get sicker,” says Dr. Edwards, who is also a professor of pediatrics at Vanderbilt University Medical Center. There have been some reports of death for pregnant women with Covid-19, though research in this area is too new to know whether there’s a solid link between Covid-19 and maternal death.

(Learn more about what it’s like to be pregnant during the pandemic.)

Myth: The vaccine isn’t safe because it was developed so quickly

Wrong again.

“The time frame has been telescoped,” says Dr. Edwards. “But in terms of the number of people enrolled in the clinical trials, the meticulousness of the safety assessments, there were no short cuts.”

Researchers took the same steps that they would for any other trial, but they did overlap some of them so as to collect data sooner.

Some aspects of the vaccines’ development differed compared with typical drug studies, and this made it possible to produce vaccines faster. For instance, so many people got sick so fast that it didn’t take vaccine manufacturers long to get the results they needed.

The large number of people getting sick all at once also made it easier for researchers to find and enroll people in clinical trials. And scientists may have had more resources than usual because of money invested in Covid-19 vaccine research.

Some people are also concerned that the messenger RNA (mRNA) technology used to develop the Pfizer-BioNTech and Moderna vaccines is too new and doesn’t have a track record. This isn’t correct either.

The technology had already been developed so that it would be ready should a pandemic like this one arise, according to Johns Hopkins Medicine. (Learn about the differences between Pfizer vs. Moderna vaccines.)

Myth: The vaccine can give you Covid-19

“It’s absolutely not possible,” says H. Dirk Sostman, MD, president of the Houston Methodist Academic Institute. According to the Centers for Disease Control and Prevention (CDC), none of the vaccines being used now or being developed contain live SARS-CoV-2, the virus that causes Covid-19. That means they can’t give you Covid-19.

The mRNA vaccine has no virus at all, dead or alive. Instead, the messenger RNA delivers instructions so the cells themselves can create the spike protein targeted by most vaccines. That protein itself can not infect you.

Bear in mind that it can take a few weeks for full immunity to build up after getting the vaccine. It is possible to get Covid-19 during this ramping-up period. Make sure you receive both doses of the Moderna and Pfizer-BioNTech vaccines to get full immunity. The Johnson & Johnson vaccine only requires one shot.

(Here’s what to do if you missed your second dose of the Covid-19 vaccine.)

Myth: The side effects can kill you

Even though the vaccine can’t give you Covid-19, it can cause side effects. These are rarely serious.

The most common side effects are a sore arm along with a slight fever, muscle aches, chills, and a headache. Think of these as welcome signs that the vaccine has activated your immune system so it will be ready to fight SARS-CoV-2 should the two ever meet. (Here are some Covid-19 vaccine stories from real people.)

The most serious adverse effect has been a type of allergic reaction called anaphylaxis. While this can be life-threatening, no one has died after receiving a Covid-19 vaccine, and few people have even had the reaction.

“It’s about two to five occurrences per million vaccinations,” says Dr. Sostman. “That’s a little bit more than what we see with the seasonal flu vaccine, which is one to two per million.”

An article appearing February 12 in JAMA found only 66 cases of anaphylaxis among almost 18 million vaccinations administered. The Food and Drug Administration continues to keep an eye out for any unexpected reactions.

Another misconception about the Covid-19 vaccine is that you cannot get it if you have an egg allergy. That’s not true. No eggs were used in the production of vaccines.

Still, people with any allergy, including an egg allergy, need to be alert to the possibility of an anaphylactic reaction after getting vaccinated.

(Learn why woman may report more Covid-19 vaccine side effects than men.)

Myth: I don’t need the vaccine if I’ve already recovered from Covid-19

Officials recommend that even people who have had Covid-19 get vaccinated. That’s because no one knows yet how long immunity from the virus lasts.

Preliminary data published in February in Science suggest that immunity from the illness can last at least six months in most—but not all—people.

One thing to remember: Don’t get vaccinated while you’re still sick. You don’t want to give your immune system two hits at the same time.

“The guidance is that you should get the vaccine if you have recovered,” says Dr. Edwards. If you received treatment with monoclonal antibodies or convalescent plasma, two emerging potential treatments for Covid-19, wait at least 90 days, advises the CDC.

Covid-19 vaccine silhouetteAndriy Onufriyenko/Getty Images

Myth: The vaccine will change my DNA

This myth may have arisen from the fact that the Pfizer-BioNTech and Moderna vaccines contain messenger RNA. RNA is a type of genetic material, but it’s not the same as DNA, explains Dr. Sostman.

The RNA does not enter the cell nucleus, which is where your DNA lives.

“It does all of its work in your cell cytoplasm,” he explains. That’s the outer portion of the cell. Plus, the instructions mRNA carries to your cells are only for a piece of SARS-Cov-2, not the whole virus.

The recently approved Johnson & Johnson vaccine uses an inactivated virus to pass the instructions on to the cells. Again, the instructions are only for a piece of the virus, and a harmless one at that.

The Johnson & Johnson vaccine is similar to the Ebola vaccine that has been given to hundreds of thousands of people with no lasting ill effects, adds. Dr. Edwards.

Myth: The vaccines contain fetal tissue

The vaccines do not contain fetal cells or fetal tissue, says Dr. Edwards. They were tested using cells originally taken from fetal tissue, but these date back to the 1960s and 1970s.

The Pfizer-BioNTech and Moderna vaccines weren’t developed with the use fetal cell cultures. Johnson & Johnson used fetal cell cultures when developing its vaccine but it contains no fetal tissue or fetal cells.

Myth: The vaccines implant tracking devices

The only thing the vaccines put into your body is a harmless way to stimulate the immune response you will need if you ever encounter Covid-19.

In addition to mRNA, the Pfizer-BioNTech vaccine contains lipids (fats) to protect the RNA, salts to balance the pH level, and sugar.

The Moderna vaccine contains a similar set of ingredients, while the Johnson & Johnson version contains the defanged virus with stabilizing compounds plus several inactive ingredients, according to the CDC.

Myth: The vaccines will give me a positive Covid-19 test

The SARS-CoV-2 virus will turn up a positive result on a viral test, but the vaccine won’t, says the CDC. There are two types of diagnostic tests that will tell you if you are currently infected with the virus that causes Covid-19.

Nucleic acid amplification tests—also known as PCR tests—look for genetic material from the virus itself, while antigen tests—also known as rapid tests—look for proteins from the virus. The first is more accurate but often takes longer.

Antibody tests are different. They measure antibodies, the immune system compounds that your body generates to protect you from infections.

Antibodies circulate in your blood even after you’ve recovered, and they can be a sign you were infected with SARS-CoV-2 in the past. Vaccinations cause your immune system to produce those protective antibodies while skipping the potential danger of the virus itself.

Experts don’t yet know if vaccinations can influence antibody tests.

Learn more about tests for Covid-19 and about coronavirus antibody testing.

Myth: I don’t have to wear a mask after getting vaccinated

Actually, you do. This is because we don’t know if people who have had the vaccine can get asymptomatic (that is, symptom-free) Covid-19 then pass the virus on to others.

So far, research on the vaccines’ ability to prevent asymptomatic spread looks promising. The results of a recent Israeli study, made public via a news release, found that the Pfizer-BioNTech vaccine was 94 percent effective in preventing asymptomatic transmission.

The CDC recently updated its guidance to say that small groups of people who have all been vaccinated can congregate indoors without masks.

But the new guideline doesn’t apply to non-vaccinated people. And it’s still important to maintain a six-foot distance from others.

“The issue is that until everybody has been vaccinated, some people are still at risk,” says Dr. Sostman. “Until we know for sure that you can’t transmit Covid-19 after you’ve been vaccinated, it’s your civic duty to be super cautious and make sure you’re protecting others.”

Next, here are the do’s and don’ts for those fully vaccinated against Covid-19.


Amanda Gardner
Amanda Gardner is a freelance health reporter whose stories have appeared in cnn.com, health.com, cnn.com, WebMD, HealthDay, Self Magazine, the New York Daily News, Teachers & Writers Magazine, the Foreign Service Journal, AmeriQuests (Vanderbilt University) and others. In 2009, she served as writer-in-residence at the University of Wisconsin School of Medicine and Public Health. She is also a community artist and recipient or partner in five National Endowment for the Arts grants.