Mar 25, 2021 2:00 PM

Author: University of Utah Health Communications

Information about COVID-19 is constantly evolving as more is learned about the virus. Some information shared online and on social media is misleading, influencing the decision whether to get vaccinated or not. Sankar Swaminathan, MD, chief of the Division of Infectious Diseases at University of Utah Health, sets the record straight on some of the myths about COVID-19 vaccines.

MYTH: Development of COVID-19 vaccines was rushed.

FACT: While it was done quickly, the vaccines were not rushed. The term “rushed” suggests something was done differently than normal or that corners were cut. In fact, tens of thousands of participants were studied in the safety and efficacy trials. In a normal vaccine trial, enough people have to get the disease to know whether it works or not. This often means waiting for a long time. With COVID-19, because the virus was so widespread, and disease occurs soon after infection, it was possible to complete the studies much sooner. The development of these vaccines was also based on a wealth of scientific work that had been done previously in the laboratory and in animals.

MYTH: One vaccine (Pfizer-BioNtech, Moderna, Johnson & Johnson) is better than the other.

FACT: The Pfizer-BioNtech and Moderna vaccines are very similar and based on the same mRNA technology. Both of these vaccines require two doses for full protection. The Johnson & Johnson vaccine is a viral vector vaccine (not live virus) and has been shown to prevent COVID-19 in a single dose. The duration of all three vaccines are being studied. Booster shots are recommended six months following the second dose of the Moderna and Pfizer-BioNTech vaccines and two months after receiving the Johnson & Johnson vaccine.

MYTH: mRNA cannot be trusted because it’s a new type of vaccine.

FACT: Messenger RNA is a small molecule that is made by cells in your body and by bacteria and viruses. It’s a blueprint for how to make a protein. The Moderna and Pfizer-BioNTech vaccines consist of mRNA that’s been made in the lab. When it gets in your cells, the mRNA instructs them to make a version of the spike protein that SARS-CoV-2 makes. This small, harmless piece of the virus cannot cause COVID-19, and mRNA vaccines do not change your DNA in any way. This is just a clever way of introducing the spike protein into your body so the body can learn how to fight it off. It’s similar in that way to a tetanus shot, where instead of mRNA you actually inject the tetanus protein.   

While it is true that mRNA vaccines have not been widely used before, these two vaccines have been tested in tens of thousands of people to demonstrate both safety and efficacy. Side effects are possible after receiving a COVID-19 vaccine, but serious adverse events are extremely rare. The COVID-19 vaccines are effective, safe, and the best option to prevent millions of infections and deaths against the virus.

MYTH: The second dose of the Pfizer-BioNTech and Moderna vaccines is not needed.

FACT: Two doses of the Pfizer-BioNTech and Moderna vaccines are needed because that is what was studied and shown to work for immunity. When someone is first exposed to a vaccine or a foreign substance, the body generates cells that can recognize that foreign substance. The second time a person gets exposed, they develop a stronger immunity and build long-term immunity. What you generally find is the response after the second dose is much larger in magnitude and longer lasting.

MYTH: The vaccine will not protect against COVID-19 variants.

FACT: The COVID-19 vaccines have shown to prevent severe illness, hospitalization, and death against all variants. It is normal for viruses to mutate. As they do, vaccine efficacy could lessen as more variants emerge over time. This is why we are seeing breakthrough infections. Booster shots are available for people ages 16 and older to help the body maintain a higher level of immunity and protection against emerging variants.

MYTH: Older adults with poor health should not get the vaccine.

FACT: It is even more important for older adults to get vaccinated. This group is at higher risk of hospitalization, experiencing complications from the virus, and even death. Moderna and Pfizer-BioNTech trials (~10,000 people between the ages of 65-90 participated) showed the vaccines were safe and just as effective in this age group.

A COVID-19 vaccine will lower the risk of getting sick if are exposed to the virus. It’s possible to still contract COVID-19 after receiving the vaccine, but evidence suggests the vaccine may keep you from getting seriously ill if you get infected. Getting the vaccine may also help protect the people you’re around, especially those who are at increased risk of becoming seriously ill from COVID-19.

MYTH: Those who have allergies should not get the vaccine.

FACT: Out of the tens of thousands of people who were tested in the initial COVID-19 vaccine trial, there were no serious adverse effects. Now that the vaccine has been given to more than 200 million people in the U.S., there have been a very small number of adverse effects.

If a person had a previous severe allergic reaction such as face swelling, difficulty breathing, or treatment with an EpiPen after a vaccination, they should discuss with their doctor whether it’s safe to get the COVID-19 vaccine. Common allergies like hay fever or food allergies are not a reason to avoid the vaccine. There is a greater chance of experiencing long-term side effects or dying from COVID-19 than experiencing an adverse reaction to the vaccine.

MYTH: You don’t need to get the vaccine if you’ve already had COVID-19.

FACT: Those who already had COVID-19 should get vaccinated. While a person gets natural immunity from the virus, the level of protection and how long it lasts is not known. Data show that COVID-19 vaccination provides added protection after getting infected with the virus.

MYTH: The vaccine can harm fertility or pregnancy.

FACT: There is no data to support COVID-19 vaccines harming fertility. However, data does show that pregnant women have an increased risk for severe illness from COVID-19. Those who are pregnant should consult with their obstetrician and discuss whether the vaccine is appropriate for them.

MYTH: COVID-19 vaccines can make you sick.

FACT: COVID-19 vaccines cannot make you sick with COVID-19, but it is common to experience side effects after getting vaccinated. Some symptoms include injection site pain, muscle aches, chills, fatigue, and fever. These side effects can be treated with over-the-counter medication. Severe allergic reactions to COVID-19 vaccines are possible but extremely rare. Anaphylaxis, thrombosis and Thrombocytopenia syndrome (TTS), and cases of myocarditis and pericarditis has been reported.

COVID-19 vaccines are not 100% effective, and it’s still possible to experience a breakthrough infection after getting vaccinated. Data shows COVID-19 vaccines are highly effective in preventing severe illness, hospitalization, and death from the virus.

MYTH: You can ditch the mask after getting vaccinated.

FACT: Due to highly transmissible variants of SARS-CoV-2, masks are recommended indoors in public for both unvaccinated and vaccinated individuals. It’s important to wear a well-fitting mask over your nose and mouth to help reduce the spread of the virus to others.

COVID-19 vaccine resources:


This information was accurate at the time of publication. Due to the changing nature of the COVID-19 pandemic, some information may have changed since the original publication date. 

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