COVID-19 Vaccine Safety Update

“Men willingly believe what they wish."

- Gaius Julius Caesar

“It pays to keep an open mind but not so open your brain falls out."

- Carl Sagan, 20th Century American Astronomer

The development and approval of two mRNA COVID-19 vaccines in less than one year’s time in 2020 remains the single most remarkable success story of the researchers, companies, and governmental organizations involved in this colossal undertaking. We should all be celebrating.

The enormous amount of data collected since the vaccines were released over two years ago reflects the efficacy and the safety of these vaccines. Nonetheless, when Bronny James, the 19-year-old son of basketball legend LeBron James, suffered a sudden cardiac arrest during a basketball practice on July 25, 2023, COVID-19 vaccine conspirators made unsubstantiated claims that there was a causal link between James’ cardiac arrest and the COVID-19 vaccine. (See, e.g., Rachel Schraer, BBC News, Health and disinformation reporter’s article “Elon Musk tweet boosts vaccine conspiracies targeting LeBron James’ son.”). In this Germ Gems post, I dispel some of the misinformation and disinformation that still abounds about the vaccines.

Sudden cardiac arrest. Sudden cardiac arrest is when your heart is functioning and then stops—you have a heartbeat one minute and no heartbeat the next. Your heart simply stops beating and you stop breathing. Sudden cardiac arrest has not been reported as a side effect of COVID-19 vaccination and is not recognized as an adverse effect of the vaccine. It is, however, the leading cause of death in young athletes.

Estimates vary, but some reports suggest that about 1 in 50,000 to 1 in 80,000 young athletes die of sudden cardiac arrest each year. The causes of sudden cardiac arrest in young athletes include what is called hypertrophic cardiomyopathy, a thickening of the heart muscle that is often observed in elite athletes and sometimes in individuals with certain genetic predispositions. Males are at a greater risk than females, and black male athletes are more likely to suffer sudden cardiac arrest than other ethnic groups.

Fortunately, an expert emergency response team quickly resuscitated Bronny James. We now await the assessment of experts—the cardiologist and other doctors caring for him—regarding the cause of his sudden cardiac arrest.

The COVID-19 vaccine misinformation and disinformation pandemic. The American Psychological Association defines misinformation as “false or inaccurate information—getting the facts wrong.” On the other hand, disinformation is “false information which is deliberately intended to mislead—intentionally misstating the facts.”

Anti-vaxxers are targeting the COVID-19 vaccines by spreading misinformation and disinformation about the safety of the vaccines. For example, in a meeting with Louisiana lawmakers in 2021, Robert F. Kennedy, Jr. made the unsubstantiated claim that the COVID-19 vaccine is the “deadliest vaccine ever made.” The facts clearly show otherwise.

The mRNA COVID-19 vaccines are effective and safe. We now have two and a half years’ experience with the mRNA COVID-19 vaccines. According to the Centers for Disease Control and Prevention (CDC) COVID Data Tracker, as of May 2023 an estimated 144,182,870 COVID-19 vaccinations were administered in the U.S. (Bronny James received one.) By the end of 2022, it’s estimated that more than 3 million lives were saved in the U.S. due to the COVID-19 vaccines.

Vaccines like all new drugs or treatments are subject to randomized clinical trials (RCTs) before they can be sold on the market. As is the case for assessing vaccine efficacy, RCTs are the cornerstone of determining vaccine safety. Such trials compare the results of a new treatment or in this case preventative measures (such as, a new vaccine) versus a placebo. There are three phases to complete in the clinical trial process before a sponsor can submit their treatment (or vaccine) to the Food and Drug Administration (FDA) for consideration to be sold on the market.

Phase 1 Clinical Trials are carried out in small groups of healthy volunteers to ensure preliminarily that the treatment is safe. If successful and approved by the FDA to proceed, Phase 2 Clinical Trials are performed in a larger number of volunteers to determine the right dosage. Normally, there is a “control group” that receives either the standard of care treatment or a placebo. If all goes well, Phase 3 Clinical Trials involving a much larger group of volunteers are performed to determine whether the treatment would be safe and effective for a wide range of people. These trials normally involve random assignment of participants to treatment (or vaccination) or control groups.

After approval by the FDA, the process enters what is called Phase 4 Clinical Trial/Post-Market Surveillance/Report Adverse Events. For the entire time the treatment (or vaccine) is on the market, the FDA monitors for safety.

The safety monitoring program for the COVID-19 vaccines was the most intense safety monitoring program in U.S. history. And, the FDA and the CDC continue to monitor the safety of these vaccines. In light of the success and safety of the vaccines, the CDC continues to recommend that everyone ages six months and older get vaccinated to protect against COVID-19.

What are the known side effects of COVID-19 vaccination? On July 13, 2023, the CDC provided an updated report, “Selected Adverse Events Reported after COVID-19 Vaccination.” Some people have no side effects, but many reported a variety of generally mild to moderate side effects that resolve in a few days. While people receiving COVID-19 vaccines are significantly less likely to die from COVID-19, they are also at no greater risk of death from non-COVID-19 causes due to getting vaccinated.

The most serious adverse effect reported after COVID-19 vaccination is anaphylaxis, a severe type of allergic reaction. It is, however, rare—occurring at a rate of approximately five cases per one million vaccine doses administered.

What about heart disease? Myocarditis (inflammation of the heart muscle) is a rare heart disease most commonly caused by an infection. While myocarditis can lead to a cardiac arrest, it routinely responds to anti-inflammatory medicine and rest.

The CDC and FDA state that there is a risk of myocarditis after COVID-19 vaccination. This side effect is, however, rare and the risk of it occurring is small.

The risk is highest in males in their teens and early 20s, and occurs more commonly after the second vaccine dose and within several days after vaccination. One or two recipients out of every 10,000 are affected.

To date, the benefits of the mRNA vaccines—not getting COVID-19 and its related and possibly severe complications such as long-term health problems, hospitalization and even death—outweigh the risks of the potential side effects of the vaccines. We can be grateful that the CDC and the FDA continue to monitor for adverse effects of COVID-19 vaccines. I just wish there were a way to monitor for, and to stop, the adverse effects of the misinformation and disinformation pandemic.