10 things you need to know about COVID-19 vaccines

Local medical experts discussed their current understanding of COVID-19 vaccinations and answered audience questions at a recent webinar sponsored by USF Health.

Panel members included Dr. Kevin B. Sneed, PharmD, Dean and Professor of the USF Taneja College of Pharmacy, and Dr. Kami Kim, Professor of Medicine and Director of the Division of Infectious Disease and International Medicine at USF.

Here are 10 takeaways from that discussion:

1. What will I feel after my vaccination from either the Moderna or Pfizer product?

Dr. Sneed noted the most common side effect is local pain at the injection site which typically lasts up to 24-36 hours. Second most common are headache and fatigue, experienced by more than 50% of people, and usually after the second shot. About 1 in three people may experience chills or fever. Dr. Sneed stated he was not aware of reports of any serious anaphylactic reactions to these vaccines in the Tampa region.

2. When will the Johnson and Johnson vaccine become available and which vaccine is best?

On Friday (2/26/21), the Johnson and Johnson vaccine was approved by a panel of independent experts and on Saturday (2/27/21) the FDA gave approval for Emergency Use Authorizations just as it had done previously for the Moderna and Pfizer vaccines. Meanwhile, clinical trials providing additional clinical information are continuing on all three products. The Johnson and Johnson vaccine, which will be distributed beginning this week, has a 72% efficacy, slightly lower than the other two vaccines when mild and severe disease cases are combined. But the J and J product in clinical trials -- like the other two approved vaccines -- showed very high effectiveness in preventing severe disease or death. Unlike the Moderna and Pfizer vaccines, the Johnson and Johnson vaccine requires only a single shot and has similar but somewhat less frequent side effects. The panel members, like other national experts, recommend using whichever vaccine first becomes available because the public health effectiveness of each is equivalent.

3. How does the effectiveness of COVID-19 vaccines compare to more traditional vaccines? 

Dr. Kim noted that the flu shot is much less effective -- 40-60% -- compared to COVID-19 vaccines. Measles and mumps vaccines, on the other hand, are around 90% effective. She pointed out that “respiratory viruses like the coronavirus group tend to be challenging and that’s why we have been thrilled to see high effectiveness rates in the 80-90% range including among diverse populations and the elderly.”

4. After receiving the first dose of a COVID-19 vaccine product, is it possible to receive the second dose from a different vaccine product?

Dr. Sneed noted that while switching to a different vaccine type for the second dose may be effective, the CDC strongly recommends remaining with the same product for both vaccinations since this is what was studied in clinical trials and proven to be most effective.

5. After testing positive for COVID-19 or having the disease, when should I have my first vaccination, and is a second shot needed?

The general guidance is to wait at least 90 days after being infected with COVID-19 prior to having the first vaccine dose. The second vaccine dose is recommended as well. The waiting period amounts to a timing issue, aiming to maximize protection and minimize vaccine side effects.  For example, individuals with severe COVID-19 infections, who tend to have larger antibody build-ups, may be at greater risk for more vaccine side effects if given the shot soon after the infection.  On the other hand, those with mild or asymptomatic infection may benefit from the 90-day wait by extending their duration of disease protection. This is an evolving area and the reasons for individual differences in antibody production are still not well understood. It is possible, in the future, that only one shot will be recommended after infection with COVID-19. What does seem clear is antibody response to disease tends to be less than that from vaccination. Presently, Dr. Kim noted we recommend two doses (for Moderna or Pfizer vaccines) after COVID-19 as the second shot acts as a booster, increasing antibody levels and extending protection longer.

6. Is a COVID-19 vaccination safe in pregnancy and for children?

Dr. Sneed pointed out that while pregnant women were not enrolled in the initial clinical vaccination trials, some women became pregnant after enrollment, received vaccinations, were closely monitored, and to date have not been shown to have maternal or fetal adverse effects. Of note, pregnant women who acquire COVID-19, recently have been found to be at risk for severe disease. Current CDC recommendations as well as those of other medical groups like the American College of Obstetricians and Gynecologists (ACOG) now recommend that COVID-19 vaccination “should not be withheld” during pregnancy and that pregnant patients should discuss the possibility of vaccination with their providers. During pregnancy, vaccination benefits appear to significantly outweigh risks.  ACOG also recommends that COVID-19 vaccination “be offered” to breastfeeding mothers. Last month Pfizer announced the start of a clinical trial involving pregnant women, the first COVID-19 vaccine study of its kind in the U. S. involving 4,000 women. 

As far as children, Dr. Sneed reported that clinical trials are ongoing and that a CDC recommendation regarding vaccination of children as young as 15 or even 12 is expected in the fall. Currently, the Moderna vaccine is approved for individuals 18 and older while the Pfizer vaccine is approved for those 16 and older. 

7. What’s the best way to educate the public about COVID-19 vaccines given widespread doubts, especially among minority groups?

Dr. Sneed has given more than 50 talks on this subject including to many Hispanic and African-American communities where, he notes, “there has been historic mistrust around science, especially vaccines. The number one thing I tell people is there is nothing about the vaccine that is more dangerous than coming into contact with the actual virus.” He pointed out that most people have some personal experience with friends or family who have been hospitalized, been chronically impacted with brain fog or other complications, or even died from COVID-19.  “Once you point out there is a way to prevent all of that, we begin to change hearts and minds pretty effectively,” he stated. Part of the issue, he added, is access -- ensuring that enough product reaches these underserved communities.

8. Should I get the COVID-19 vaccination if I’ve had a negative reaction to a flu vaccine in the past?

That depends on the type and severity of the adverse reaction experienced. While anaphylactic reactions are considered a contraindication to getting the COVID-19 vaccination, “a detailed risk-benefit analysis with your [healthcare] provider is the best way to make this determination,” noted Dr. Kim. With any history of side effects from previous vaccines, it is advisable to wait longer at the site after the COVID-19 vaccination is performed. Dr. Kim noted that anaphylactic reactions are quite rare. By way of reference, earlier this year the CDC reported 21 cases of anaphylactic reactions among 1.9 million Pfizer vaccinations with no deaths reported (MMWR Weekly, 1/15/2021).

9. What is “V-Safe”?

Dr. Sneed emphasized the importance of this smartphone-based tool that uses text messaging to provide personalized health check-ins after you receive a COVID-19 vaccine. Depending upon your answers, someone from the CDC may call to check in on you and obtain more information. You can register after a COVID-19 vaccination at vsafe.cdc.gov

10. After a COVID-19 vaccination, when can I return to my normal life?

Both physicians stressed the same message: COVID-19 does not confer a return to “business as usual.” Since vaccinations are at best 95% effective, protective measures like mask-wearing will remain in place for some time. The safest scenario occurs when both you and your friends and family have all been vaccinated. In public settings, where this factor is unknown, “public health measures still need to be observed,” urged Dr. Sneed. “But at least, now, with vaccines we can have some optimism.''

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Read more articles by Dr. Bruce Shephard.

Dr. Bruce D. Shephard, a retired Obstetrician-Gynecologist and Affiliate Associate Professor, Department of Obstetrics and Gynecology, USF Morsani College of Medicine, is best known locally for delivering more than 7,350 babies. He now occasionally teaches and always practices good health, dabbles in writing, and raises monarch butterflies. He and his wife, Coleen, live in Tampa.