Early safety data from the first month of COVID-19 vaccination finds the shots are as safe as the studies suggested they'd be.
Everyone who experienced an allergic response has been treated successfully, and no other serious problems have turned up among the first 22 million people vaccinated, according to the Centers for Disease Control and Prevention.
The data was collected from several tracking systems, including a voluntary one in which people who are vaccinated report their symptoms via text. Another allows people who believe they have been harmed by a vaccine to contribute their information, and athird collects reports from medical records.
Although it's never possible to prove something is completely safe, data from these tracking systems suggests the vaccines are not causing large numbers of unusual or dangerous results.
Tracking COVID-19 vaccine distribution by state:How many people have been vaccinated in the USA?
Wednesday, Dr. Tom Shimabukuro, deputy director of the CDC's Immunization Safety Office, briefed a CDC advisory committee on the agency's review of safety data collected on the two authorized vaccines.
Side effects remain a common result of both the Pfizer-BioNTech and Moderna vaccines – 70% of people who self-reported said they suffered pain.
Vaccinated people have suffered major health crises and even death within a few days of receiving a shot, but the rate of those events is no higher than would be expected in the general population and cannot be connected to the vaccine, the review found.
More than 2 million people out of the first 22 million to receive at least one dose of vaccine reported to the V-safe, a self-reporting system involving web surveys and text messages.
Of these, more than 70% reported pain, 33% fatigue, 30% headaches, 23% muscle pain and about 11% chills, fever, swelling or joint pain.
There was little difference in reported side effects between the two vaccines, though people generally had a harder time with the second dose than the first.
More than 9,000 people reported side effects after vaccination to the CDC's Vaccine Adverse Event Reporting System, or VAERS. The problems in slightly more than 1,000 of those reports were considered serious. The majority of complaints involved headaches, fatigue, dizziness, nausea, chills, fever and pain.
A third safety reporting system, called the Vaccine Safety Datalink, looks at medical records from nine participating health care organizations, including data on more than 12 million people per year. More than 162,000 people in the system have received at least one COVID-19 shot.
In that group, there were "no signals as of January 16" of increased risk for any of 20 common conditions, which included heart attack, appendicitis, embolisms and diseases caused by low platelet counts.
In the vaccinated group, four people reported Bell's palsy, a form of facial paralysis seen in a small number of people in each of the vaccine trials. In the unvaccinated group, there were 348 cases.
One way to figure out whether COVID-19 vaccines kill people is to look at the number of people expected to die over a period of time and compare that with deaths that occurred within a few days of vaccination.
VAERS received reports of 196 deaths after COVID-19 vaccination.
Of those, 66% were residents of long-term care facilities. About 1.3 million nursing home residents were vaccinated from Dec. 21 to Jan. 18.
Luck, foresight and science:How an unheralded team developed a COVID-19 vaccine in record time
In a group that large followed over that length of time, 11,440 people would be expected to die of all causes. That led the CDC to conclude the much lower number of nursing home deaths were not caused by vaccination.
Barbara Bardenheier of the Brown University School of Public Health conducted a related study of residents at Genesis Healthcare, the largest nursing home company in the USA.
More than 7,000 Genesis residents in 118 facilities received their first vaccine dose from Dec. 18-31. After excluding people with active COVID-19 infections, the researchers found fewer deaths among the vaccinated residents compared with unvaccinated ones.
"Findings suggest that short-term mortality rates appear unrelated to vaccination for COVID-19 in skilled nursing facility residents," according to a summary of the study's results.
The CDC found no causal link between vaccination and deaths among younger, healthier people.
Among 13.7 million people under 65, 168 people would be expected to suffer a sudden, lethal heart attack over a typical 35-day period. By comparison, 18 such deaths were reported to VAERS among people who had been vaccinated.
Both vaccines have been shown to trigger a relatively high – though still rare – rate of severe allergic reactions.
Among 10 million people who received the Pfizer-BioNTech vaccine, 50 went into anaphylactic shock, a rate of five serious allergic reactions per 1 million doses. Twenty-one people out of 7.6 million who received the Moderna vaccine went into shock, a rate of 2.8 per 1 million doses.
Ninety percent of these incidents occurred within a half-hour of getting a shot, and all recovered.
Explore how COVID-19 vaccine works:An augmented reality journey into the body
By comparison, for the seasonal flu shot, the rate of anaphylaxis is 1.3 per million shots, substantially lower than the two authorized COVID-19 vaccines.
Still, "the risks of getting sick from COVID-19 are much higher than the risks of anaphylaxis," CDC Director Rochelle Walensky said Wednesday.
The CDC is investigating whether people who had COVID-19 before getting the shot were more likely to have an allergic reaction.