Myth Busting: SARS-CoV-2 Vaccine

Michael E. Pichichero, MD

March 11, 2021

MYTH: I Shouldn't Get the Vaccine Because of Potential Long-term Side Effects

We know that 68 million people in the United States and 244 million people worldwide have already received messenger RNA (mRNA) SARS-CoV-2 vaccines (Pfizer/BioNTech and Moderna). So for the short-term side effects we already know more than we would know about most vaccines.

Dr Michael Pichichero

What about the long-term side effects? There are myths that these vaccines somehow could cause autoimmunity. This came from three publications where the possibility of mRNA vaccines to produce autoimmunity was brought up as a discussion point.1-3 There was no evidence given in these publications; it was raised only as a hypothetical possibility.

There's no evidence that mRNA or replication-defective DNA vaccines (AstraZeneca/Oxford and Johnson & Johnson) produce autoimmunity. Moreover, the mRNA and replication-defective DNA, once it's inside of the muscle cell, is gone within a few days. What's left after ribosome processing is the spike (S) protein as an immunogen. We've been vaccinating with proteins for 50 years and we haven't seen autoimmunity.

MYTH: The Vaccines Aren't Safe Because They Were Developed so Quickly

These vaccines were developed at "warp speed" — that doesn't mean they were developed without all the same safety safeguards that the Food and Drug Administration requires. The reason it happened so fast is because the seriousness of the pandemic allowed us, as a community, to enroll the patients into the studies fast. In a matter of months, we had all the studies filled. In a normal circumstance, that might take 2 or 3 years. And all of the regulatory agencies — the National Institutes of Health, the FDA, the Centers for Disease Control and Prevention — were ready to take the information and put a panel of specialists together and immediately review the data. No safety steps were missed. The same process that's always required of phase 1, of phase 2, and then at phase 3 were accomplished.

The novelty of these vaccines was that they could be made so quickly. Messenger RNA vaccines can be made in a matter of days and then manufactured in a matter of 2 months. The DNA vaccines has a similar timeline trajectory.

MYTH: There's No Point in Getting the Vaccines Because We Still Have to Wear Masks

Right now, out of an abundance of caution, until it's proven that we don't have to wear masks, it's being recommended that we do so for the safety of others. Early data suggest that this will be temporary. In time, I suspect it will be shown that, after we receive the vaccine, it will be shown that we are not contagious to others and we'll be able to get rid of our masks.

MYTH: I Already Had COVID-19 so I Don't Need the Vaccine

Some people have already caught the SARS-CoV-2 virus that causes this infection and so they feel that they're immune and they don't need to get the vaccine. Time will tell if that's the case. Right now, we don't know for sure. Early data suggest that a single dose of vaccine in persons who have had the infection may be sufficient. Over time, what happens in the vaccine field is we measure the immunity from the vaccine, and from people who've gotten the infection, and we find that there's a measurement in the blood that correlates with protection. Right now, we don't know that correlate of protection level. So, out of an abundance of caution, it's being recommended that, even if you had the disease, maybe you didn't develop enough immunity, and it's better to get the vaccine than to get the illness a second time.

MYTH: The Vaccines Can Give Me SARS-CoV-2 Infection

The new vaccines for COVID-19, released under emergency use Authorization, are mRNA and DNA vaccines. They are a blueprint for the Spike (S) protein of the virus. In order to become a protein, the mRNA, once it's inside the cell, is processed by ribosomes. The product of the ribosome processing is a protein that cannot possibly cause harm as a virus. It's a little piece of mRNA inside of a lipid nanoparticle, which is just a casing to protect the mRNA from breaking down until it's injected in the body. The replication defective DNA vaccines (AstraZeneca/Oxford and Johnson & Johnson) are packaged inside of virus cells (adenoviruses). The DNA vaccines involve a three-step process:

  • 1. The adenovirus, containing replication-defective DNA that encodes mRNA for the Spike (S) protein, is taken up by the host cells where it must make its way to the nucleus of the muscle cell.

  • 2. The DNA is injected into the host cell nucleus and in the nucleus the DNA is decoded to an mRNA.

  • 3. The mRNA is released from the nucleus and transported to the cell cytoplasm where the ribosomes process the mRNA in an identical manner as mRNA vaccines.

MYTH: The COVID-19 Vaccines Can Alter My DNA

The mRNA and replication-defective DNA vaccines never interact with your DNA. mRNA vaccines never enter the nucleus. Replication-defective DNA vaccines cannot replicate and do not interact with host DNA. The vaccines can't change your DNA.

Here is a link to YouTube videos I made on this topic

Here is a photo of me receiving my first SARS-CoV-2 shot (Moderna) in January 2021. I received my second shot in February. I am a lot less anxious. I hope my vaccine card will be a ticket to travel in the future.

Pichichero is a specialist in pediatric infectious diseases and director of the Research Institute at Rochester (N.Y.) General Hospital. He has no conflicts of interest to report.


1. Peck KM and Lauring AS. J Virol. 2018. doi: 10.1128/JVI.01031-17.

2. Pepini T et al. J Immunol. 2017 May 15. doi: 10.4049/jimmunol.1601877.

3. Theofilopoulos AN et al. Annu Rev Immunol. 2005. doi: 10.1146/annurev.immunol.23.021704.115843.

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