Physician Debunks COVID-19 Vaccine Myths

Allison Liddell, M.D., Infectious Disease

Allison Liddell, M.D., is admittedly a big proponent of the COVID-19 vaccines.

She’s such a big proponent that the chief of infectious disease at Texas Health Presbyterian Hospital Dallas was among the first in line to get the Pfizer vaccine when it arrived at the hospital on Dec. 16.

“I think all the safety precautions are important, but you cannot perfectly social distance and mask the entire planet for as long as we would need to in order to get rid of this,” said Liddell, a physician on the hospital’s medical staff and a member of Texas Health Physicians Group. “We have to have something else and I think the vaccine is that other part. The vaccine gives us the edge that we need to be able to completely eliminate this.”

Liddell said the few who have shared with her their hesitation to get the vaccine included the cautious who wanted to see how others responded to the vaccine first, and those concerned because they might be pregnant or have an underlying condition.

When trying to ease people’s fear, Liddell touts the vaccine’s effectiveness.

“Compared to almost any other vaccine, it’s amazingly effective with a 95% drop in cases in the vaccine group versus the placebo group,” Liddell said. “Think of it this way, they gave 36,000 people this vaccine and 162 people in the placebo group got COVID and only 8 in the vaccine group did. That’s a huge, huge decrease.”

She also shares that the vaccines had a very low rate of serious adverse reactions in clinical trials and prepares them for what they may experience.

“I talk to them about the side effects being more common after the second dose because your body is already primed for that protein that’s being made so it reacts to it a little more and that’s just a sign that your immune system is working,” Liddell said. “And the side effects that do happen, they happen within a day or two. They don’t happen weeks later or months later. There is no evidence that there are any long-term side effects from this vaccine.”

For Liddell personally, the side effects were minimal.

“I personally had some fever for about 24 hours and just kind of general achiness after the second dose and I took some Advil and was fine and able to work,” she added. “I do know some people who felt bad enough to not work the day after but that was all temporary, and in my opinion, 100% worth the incredible effectiveness of the vaccine.”

Below, Liddell debunks some of the vaccine myths she’s heard in her own words:


Myth: The vaccine will affect or alter my DNA

Dr. Liddell:  “This is false. Messenger RNA, a molecule that we all have in our bodies, is like a recipe that tells our body how to make the proteins that we need. COVID-19 mRNA vaccines, such as the Pfizer and Moderna vaccines, don’t go anywhere near your DNA or affect it at all.

It just tells your natural little protein factories in your cells — your ribosomes — how to make this protein so your immune system can react against it. It’s a very simple, elegant, really cool vaccine that is designed to be safer than vaccines in the past, which often were live vaccines.”


Myth: A 95% efficacy rate means 5% of those vaccinated will still get COVID-19.

Dr. Liddell:  “Your chance of getting COVID depends on how much there is in the community. That 95% is how much the rate was decreased; it’s not that 5% of the people getting the vaccine are going to get COVID. It’s much lower than that.

So, if you’re a healthcare worker and you get the vaccine, it makes your chance of getting COVID extremely small, much lower than 5%. And it will get lower and lower as the incidence in the community goes down.”


Myth: If I get the COVID-19 vaccine, I am no longer at risk for contracting the virus and no longer have to take safety precautions like wearing a mask.

Dr. Liddell:  “If you get this vaccine, you are very unlikely to develop severe COVID, but you can still potentially get COVID and that’s important to know. The vaccine may not prevent mild asymptomatic infections, so it’s important to keep masking and social distancing so you don’t inadvertently give the virus to an unvaccinated friend or family member.

“We can’t ease up on prevention until the vast majority of people are vaccinated and the number of cases in our community is way down. This is our chance for all of us to come together to rid us of this pandemic, of which we are all so sick.”

In addition to Dr. Liddell’s comments, we want to review some more common myths circulating about the vaccine and clear up the confusion with reliable facts:

More information on what we know about the COVID-19 vaccines can be found here and is being updated regularly, so check back often.

This content is subject to change as additional data become available.

Leave a Reply

All comments are moderated before they’re posted, and we reserve the right to moderate any comments or commenters that are abusive, libelous, off-topic, use excessive foul language, or that are indecent. Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.