By: RAFEENA BACCHUS, M.D., MEDICAL DIRECTOR

Vaccine hesitancy, whether due to vaccine fatigue, misinformation or genuine concern for side effects, is very common these days. Headlines from trusted news sources and even not-so-trusted sources come at us fast and can be misleading. So how do you know if the vaccine is right for you?

First and foremost, know that your concerns are valid and that these concerns should be discussed with your trusted physician. There are many reasons why the vaccine is important for some to receive and other times when the benefits may not outweigh the risks and therefore should be avoided.

So, let’s address some of the common concerns providers have heard.

1. Blood Clots
   The largest global study recently published by the Global Vaccine Data Network, after just shy of 1 million doses of vaccines given, showed a statistically significant increased risk of a type of blood clot in the brain after immunization with viral-vector vaccines such as the one developed by the University of Oxford and made by AstraZeneca. It showed that these vaccines were linked to a threefold increase in cerebral venous sinus thrombosis, a type of blood clot in the brain; identified in 69 events, compared with an expected 21. This vaccine was never given the U.S. In the same study, mRNA vaccines (Pfizer and Moderna) showed as small increase in observed ration of blood clots related to low platelet counts but not to statistically significant levels.

   Several smaller studies have investigated the potential link between mRNA COVID-19 vaccines and have also not found any clear associations.

2. Heart Conditions
   Myocarditis is inflammation of the heart muscle and has been seen with both mRNA and viral-vector vaccines in several studies. Though cases are rare, they are mostly seen in adolescent and young males. The severity of myocarditis can vary; however, most will have resolution of symptoms. The risk of myocarditis is 5-10 per million vaccine doses. The rate of myocarditis with COVID-19 infection is 40-80 cases per million people infected with COVID.
3. Neurological Disorders
   In the same study done by the Global Vaccine Data Network referenced above, Guillain-Barre Syndrome, a syndrome that affects the nerves, was observed to occur at a statistically significant increase in cases with viral vector vaccines. This was NOT observed with mRNA vaccines. However, inflammation and swelling in the brain and spinal cord  was observed after both viral-vector and mRNA vaccines. Seven cases of acute disseminated encephalomyelitis after vaccination with the Pfizer mRNA vaccine were observed, versus an expectation of two.

As with any vaccination, there are many potential side effects. However, it is important to note that severe side effects are very rare. In some cases, your provider may recommend against vaccination due to an underlying medical condition. On the other hand, for those in the majority, these vaccines are safe, effective, and lifesaving. Be sure to discuss with your MPCP provider when making these important health care decisions. We are here to support you any way we can.

Article Sources
K. Faksova et al., Vaccine, https://doi.org/10.1016/j.vaccine.2024.01.100
CDC. Clinical Considerations: Myocarditis after COVID 19 Vaccine. https://www.cdc.gov/vaccines/covid-19/clinical-considerations/myocarditis.html. February 24, 2024

Dr. Bacchus is a MPCP partner and is certified by the American Board of Internal Medicine. She sees patients in the Columbia office and serves as MPCP’s Medical Director.