MANKATO – Mankato doctors recently published a review of potential side effects from COVID-19 vaccines, finding that the benefits far outweigh the rare risks.
The research team from the Mayo Clinic Health System analyzed reports related to vaccines that are available both in the US and elsewhere in the world in 2020 and 2021. Their results, published in March, are featured in the official journal of the Italian Society for Infectious Diseases and tropical diseases.
Vaccines are the only tool available that gives people some protection against COVID-19, said Dr. Syed Anjum Khan, so the idea behind the paper was that researchers should gather the best information about vaccine safety.
“As a hospital practice, we care about our community, and we care deeply about the Southern Minnesota community,” said Khan, one of six researchers involved in the project. “So we really wanted to provide the best evidence.”
All vaccinations, including those developed for COVID-19, carry risks. However, misinformation about COVID-19 vaccines during the pandemic helped to create hesitation among some groups by overestimating the risks.
The research results could help providers communicate with patients about risk factors, said Dr. Hisham Ahmed Mushtaq, who wrote the research paper.
“This will give the provider a nice, detailed list of the negative effects,” he said. “They can educate their patients.”
Side effects associated with the two most common vaccines administered in Minnesota, Moderna and Pfizer’s mRNA vaccines included mild to moderate symptoms ranging from swelling and redness at the injection site to headaches and fatigue. The symptoms typically lasted for about one to two days.
Younger recipients between the ages of 16-55, especially those receiving their second dose, experienced more side effects. Younger people have more robust immune responses, Khan said, and the greater response associated with the second dose led to more adverse effects.
“At this point, the body recognizes the virus, so the immune response is more robust the second time around,” she said.
Researchers also focused on six specific types of side effects associated with different vaccines. One of them, thrombosis, prompted U.S. regulators to temporarily halt the use of the Johnson & Johnson vaccine in April 2021.
The break came after six reports of cerebral venous thrombosis, or CVT, after people received vaccines. After examining the reports, regulators lifted the pause, but issued a warning about them for women under 50.
The Mankato researchers noted that the vaccine still provides an overall benefit because the risk of getting CVT from COVID-19 is much higher.
“The development of CVT is 41 times more likely in patients with COVID-19 than those without COVID-19,” they said in the report.
Understanding risks versus benefits is important when analyzing vaccine safety, said Dr. Brian Bartlett, one of the researchers. For most patients, risks from vaccines pale in comparison to risks from COVID-19.
“No medicine or vaccine is risk-free,” he said. “What we found is, in our professional experience with the vast majority of patients, that the benefits of the vaccines outweigh the risks.”
Other reported adverse health effects either did not have significant evidence linking them to COVID-19 vaccines, such as Guillain-Barré syndrome, or had too low risk levels to outweigh the benefits of the vaccine, such as cutaneous reactions and glomerular disease.
Another adverse health effect, inflammation of the heart known as myocarditis, had more than 10,000 reported cases to the Centers for Disease Control and Prevention’s Vaccine Adverse Event Reporting System, or VAERS. But the reports, the researchers concluded, were “rare compared to the hundreds of millions of vaccine doses administered without adverse effects.”
A separate study from the CDC also showed that patients with COVID-19 had almost 16 times the risk of developing myocarditis compared to patients without COVID-19.
The VAERS database can be useful for monitoring adverse effects, even if it has drawbacks. Submissions may be biased or contain errors, the researchers concluded, and the submissions do not indicate a causal relationship between the effects and vaccines – some effects may occur randomly after vaccination instead of being the direct result of vaccination.
Overall, the goal of the study was to offer people clean, clear and objective information about COVID-19 vaccines, Bartlett said. He described the analysis as one of the most thorough, evidence-based views on risk factors to date during the pandemic.
The results are consistent with what Khan, Bartlett, and other physicians observed in patients during the pandemic. Vaccinated people were far less likely to have severe COVID-19 compared to unvaccinated people.
Bartlett credited Khan and her colleagues for helping Mayo at Mankato Hospital to have one of the highest COVID-19 survival rates in the country.
“People in this community who had COVID-19 and were hospitalized were far more likely to survive their illness than other hospitals,” he said.
It was a team effort, Khan said, just like the research project was. Dr. Anwar Khedr, Dr. Thoyaja Koritala and Dr. Nitesh K. Jain was the three other researchers involved in the analysis.
Seeing so many unvaccinated patients experience severe COVID-19 symptoms during the pandemic was difficult, Khan and Bartlett said. Publishing a clearly written analysis that put vaccine risks in context was another way of educating people.
“There were again concerns about the vaccine and we respect their decision,” Khan said. “But we noticed that of all the people admitted to the intensive care unit, about 99% were those who were not vaccinated.”