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KU Medical Center researcher is first author on COVID-19 vaccine safety study showing low rates of severe adverse events

An observational study led by Halinder Mangat, M.D., demonstrated that rates of severe adverse events after COVID-19 immunization are very low compared with the risks from COVID-19.

up close up photo of an injection needle being filled with medicine from a vial
A study led by KU associate neurology professor Halinder Mangat, M.D., confirmed the overall safety of the three COVID-19 vaccines approved in the United States.

Halinder Mangat, M.D., an associate professor in the Department of Neurology at the University of Kansas Medical Center, is the lead author on a research paper confirming the overall safety of the two mRNA vaccines and the single adenovirus vector COVID-19 vaccine in the United States.

In an observational study published in Frontiers in Public Health last month, Mangat and the research team, which included collaborators from the United Kingdom, Germany, India and the Netherlands, found that over a one-year period there were very low overall cumulative reported rates of severe adverse events from the three COVID-19 vaccines. The findings were based on data from a publicly accessible vaccine safety surveillance database and included all reported instances up to 28 days after vaccination.

“While part of the safety may be dependent on selecting different vaccines for different age groups, the overall safety profile of both mRNA (Pfizer and Moderna) and adenovirus vector (Janssen) vaccines is very good,” Mangat said. “In the context of COVID-19, risks of such severe adverse events following immunization appear to be significantly lower than from COVID-19 in adults.”

The study team found 88,626 severe adverse events after immunization (sAEFI) reported out of 485 million vaccine doses administered nationwide over a one-year period.

In the study, researchers looked at the rates of sAEFI reported to the Vaccine Adverse Events Reporting System (VAERS) between December 13, 2020, and December 13, 2021, for each of the SARS-CoV-2 vaccines authorized for emergency use and attributed to the SARS-CoV-2 vaccination programs across all states and territories in the United States. Severe adverse events included emergency department visits, hospitalizations, life-threatening events and deaths.

Given the low rates of severe adverse events with the three COVID-19 vaccines, the study concluded that immunization should remain a critical tool for adults for decreasing severity of COVID-19 in the United States. Researchers also noted that data confirming the safety of the vaccines should be the centerpiece of public health messaging to help fuel vaccine uptake and combat vaccine hesitancy.

The study team wrote that the findings should bolster confidence in adenovector virus vaccines and their continued use globally, including some remote areas where refrigeration is difficult or impossible.

“The results from this study should encourage people who have been skeptical about vaccine safety to take the vaccines,” Mangat said. “At a global level, these data also provide safety reassurance for the continued use of adenovector virus vaccines, which do not pose cold-chain logistical challenges.”

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