The vast majority of reactions reported were mild, such as headaches and fatigue.
In clinical trials, Pfizer and Modern COVID-19 vaccines demonstrated low rates of serious adverse events. Now, real-world data from the first month of vaccine administration in the U.S. corroborates that data.
A new CDC report looks at the numbers of VAERS, a government-controlled vaccine safety portal where U.S. health workers are required to report adverse events after vaccines.
In a month where nearly 14 million vaccine doses were administered, only about 7,000 reports were sent to VAERS, 91% of which described mild events, such as headache, fatigue, and dizziness.
Anaphylaxis, a vaccine reaction that garnered widespread media coverage, was uncommon: a total of 62 cases were reported, at a rate of 4.5 per million doses, comparable to the rate of anaphylaxis with other vaccines. usual.
Amid the 14 million doses, 113 deaths were reported in VAERS; 78 long-term care centers and 35 off-premises and so far none of these deaths have been directly related to the vaccine.
The data isn’t entirely surprising, says William Schaffner, MD, a professor of preventive medicine and infectious diseases at Vanderbilt University Medical Center.
“Understanding the safety assessment has been better than we have done for any licensed vaccine we have used in the United States,” he told ABC News. “Clinical trials of both vaccines were very extensive and both showed low rates of serious adverse reactions.”
The CDC also collected data reported by patients from v-safe, a smartphone app to voluntarily report adverse events. Of the 1.6 million vaccine recipients who participated, most reported mild side effects such as injection site pain, fatigue, headache and chills. These symptoms were reported to be most pronounced on the first day after injection, and worsened with the second dose, but improved each subsequent day, disappearing on day 3 or 4.
The app also collected data on the status of pregnancy and the nearly 11,000 women who reported being pregnant will be tracked in a specific registry.
CDC data is limited, as it relies heavily on self-reported data. For example, in both VAERS and v-safe reports, most adverse events were observed in women. But, as Schaffner describes, this does not necessarily mean that women are more prone to reactions.
“I am more inclined to believe that this is an information bias,” she said, describing the well-documented difference in the use of health care between men and women. “Women are more inclined to seek medical attention and more inclined to report illness.”
Those who judged the pace of vaccine deployment as too hasty may be confident of CDC reports, Schaffner says.
“Now that we have very well analyzed data, from a completely complete set of surveillance systems, we can go beyond very broad studies and say, look, we do it in the real world, among your friends and neighbors,” He said. he said. “This vaccine is still very, very safe.”
Eric Silberman, MD, a resident physician in internal medicine at Northwestern Memorial Hospital, is a contributor to the ABC News Medical Unit.