When analyzing adverse effects after receiving either the Pfizer-BioNTech or Moderna Covid-19 vaccines, serious reactions accounted for less than 10% of those events according to a study conducted by the US Centers for Disease Control.
Researchers evaluated safety data that was reported through the Vaccine Adverse Event Reporting System (VAERS) between Dec. 14, 2020 and Jan. 13 2021. During that time, 13,794,904 vaccine doses had been administered in the US and 1,602,065 had enrolled in the reporting system.
Out of that 1.6 million, 50.8% received the Pfizer-BioNTech and 49.2% received the Moderna vaccines.
The study found that during this time there were 6,994 reports of adverse reactions after receiving a vaccine. 6,354 (90.8%) of those events were considered non-serious and 640 (9.2%) were considered serious.
The most commonly reported symptoms were headache (22.4%), fatigue (16.5%) and dizziness (16.5%).
A total of 113 deaths were reported to VAERS with 78 (65%) of those occurring in long term care facility residents.
However the study noted, “available information from death certificates, autopsy reports, medical records, and clinical descriptions from VAERS reports and health care providers did not suggest any causal relationship between COVID-19 vaccination and death.”
Reports of anaphylaxis was also rare with just 62 reported incidents.
The study notes the there are limitations due to reporting biases and the fact that the reporting system is a voluntary self-enrollment program.
It is also important to note that during the study’s time period, first and second doses of Pfizer-BioNTech’s vaccine had been made available, but only first doses of Moderna’s vaccine.
“These data provide reassurance and helpful information regarding what health care providers and vaccine recipients might expect after vaccination,” wrote the researchers.