The number of fully vaccinated people who have later been infected with coronavirus is extremely low, according to new data from the CDC.
The Centers for Disease Control and Prevention on Tuesday reported a total of 10,262 COVID vaccine breakthrough infections as of April 30 when 101 million people in the U.S. had been fully vaccinated against the virus.
More than a quarter of the cases — 2,725 — were asymptomatic, and 995 patients were known to be hospitalized. Among the 995 hospitalized patients, 289 were asymptomatic or hospitalized for a reason unrelated to COVID-19.
The CDC reported that 160 patients died, and 28 of those who died were asymptomatic or died from a cause unrelated to COVID. The median age of patients who died was 82 years old.
“Even though FDA-authorized vaccines are highly effective, breakthrough cases are expected, especially before population immunity reaches sufficient levels to further decrease transmission,” the CDC wrote in its report.
“However, vaccine breakthrough infections occur in only a small fraction of all vaccinated persons and account for a small percentage of all COVID-19 cases,” the CDC added. “The number of COVID-19 cases, hospitalizations, and deaths that will be prevented among vaccinated persons will far exceed the number of vaccine breakthrough cases.”
The number of reported breakthrough cases is likely a “substantial undercount” of all infections among fully vaccinated people, according to the CDC. The national surveillance system relies on voluntary reporting, and data might not be complete or representative.
Many people with vaccine breakthrough infections, especially those who are asymptomatic or who experience mild illness, might not seek testing.
The Food and Drug Administration has issued emergency use authorizations for three COVID-19 vaccines — Pfizer, Moderna and Johnson & Johnson.
In large, randomized-controlled trials, each vaccine was found to be safe and effective in preventing infections. The CDC recommends that all people 12-and-older get vaccinated with an FDA-authorized vaccine.
The CDC said, “Despite the high level of vaccine efficacy, a small percentage of fully vaccinated persons (i.e. received all recommended doses of an FDA-authorized COVID-19 vaccine) will develop symptomatic or asymptomatic infections with SARS-CoV-2, the virus that causes COVID-19.”
