Only a tiny fraction of the nearly 14 million COVID-19 vaccine doses administered in the first month of vaccinations produced any sort of adverse event, U.S. health officials report.
There were 6,994 reports of adverse events following a shot of the COVID vaccine between Dec. 14, 2020 and Jan. 13, 2021, amounting to about half a percent of the 13.8 million doses doled out during that period, the U.S. Centers for Disease Control and Prevention study found.
"The CDC safety data on the first 13 million-plus vaccinations substantiates the fact that the Pfizer and Moderna COVID vaccines are very safe and have a risk-benefit ratio that unequivocally favors their use," said Dr. Amesh Adalja, a senior scholar with the Johns Hopkins Center for Health Security in Baltimore.
Symptoms most frequently reported were headache (22%), fatigue (16.5%) and dizziness (16.5%), according to the study published Feb. 19 in the CDC's Morbidity and Mortality Weekly Report.
There were 640 serious adverse events reported (9% of all adverse events), including 113 deaths.
Available records suggest that the COVID-19 vaccine played no part in these deaths, which mainly occurred among people in long-term care facilities, said the researchers, who were led by Julianne Gee, from the CDC's COVID Response Team.
Cases of anaphylaxis were rare, amounting to 4.5 for every 1 million doses administered, the CDC found. By comparison, the flu vaccine causes 1.4 cases of anaphylaxis per million, the pneumonia vaccine 2.5 per million, and the shingles vaccine 9.6 per million.
There were a total of 62 reports of anaphylaxis: 46 from the Pfizer vaccine and 16 after the Moderna vaccine.
The data came from the CDC's Vaccine Adverse Event Reporting System, as well as from an active surveillance system called V-safe, the researchers said.
To allay concerns about the rapid development and testing of the COVID-19 vaccines, the U.S. federal government "has implemented the most comprehensive vaccine safety monitoring program in its history," the report added.
No unexpected patterns of reactions or other safety concerns have been identified during this early monitoring, the authors said.
"These initial findings should provide reassurance to health care providers and to vaccine recipients and promote confidence in the safety of COVID-19 vaccines," the report concludes.
The U.S. Centers for Disease Control and Prevention has more about COVID-19 vaccines.
SOURCES: Amesh Adalja, MD, senior scholar, Johns Hopkins Center for Health Security, Baltimore; Morbidity and Mortality Weekly Report, Feb. 19, 2021