CDC reports 5,800 breakthrough COVID-19 infections in people who were vaccinated. Doctors say, 'Don't panic.'

The Centers for Disease Control and Prevention has found about 5,800 cases of COVID-19 infections among people who have been fully vaccinated in the U.S., according to a new report.

CDC officials tell Yahoo Life that as of April 13, about 5,800 breakthrough COVID-19 infections — meaning someone who was fully vaccinated against the virus still contracts COVID-19 — have been reported to the CDC among the more than 66 million Americans who have been fully vaccinated. Of those, 396 (or 7 percent) required hospitalization and 74 people (0.0001 percent) died.

Overall, it amounts to a rate of 0.008 percent of Americans who have been fully vaccinated against COVID-19 that have gotten the infection.

Doctor in protective gloves & workwear holding Testing Kit for the coronavirus test. The doctor is collecting nasal sample for a senior woman with a sampling swab.
A doctor collects a sample with a nasal swab to test a woman for COVID-19. (Getty Images)

“COVID-19 vaccines are effective and are a critical tool to bring the pandemic under control. All of the available vaccines have been proven effective at preventing severe illness, hospitalizations and deaths,” CDC spokesperson Kristen Nordlund tells Yahoo Life in a statement. “However, like is seen with other vaccines, we expect thousands of vaccine breakthrough cases will occur even though the vaccine is working as expected.”

Nordlund adds, “To date, no unexpected patterns have been identified in case demographics or vaccine characteristics.”

Breakthrough infections were reported in people of all ages eligible for vaccination, but a little over 40 percent of the infections were in people age 60 and up. Other important information to note:

  • 29 percent of the vaccine breakthrough infections were reported as asymptomatic.

  • 65 percent of the people experiencing a breakthrough infection were female.

“The male-female differences that we’re observing ... no one has a good idea as to why it’s occurring,” Dr. Stanley H. Weiss, professor at Rutgers New Jersey Medical School and the Department of Biostatistics and Epidemiology at Rutgers School of Public Health, tells Yahoo Life. “We do know that men and women’s immune systems do tend to react differently.” Weiss says it could simply be “by chance” or may be that women are more likely to seek medical care when they have a breakthrough infection. “Were fewer men detected because of that or something biological? We don’t know the answer to that,” he says.

The CDC is monitoring the breakthrough infections and collecting data on them. The agency has also developed a national COVID-19 vaccine breakthrough database where state health department investigators can enter, store and manage data for cases in their jurisdiction.

News of any COVID-19 infections after a person has been fully vaccinated against the coronavirus can be frustrating and even scary, but doctors say it’s to be expected.

“No one expected the vaccine to be 100 percent efficacious,” infectious disease expert Dr. Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security, tells Yahoo Life. “Breakthrough cases are still extremely rare and often without any major consequence.”

The efficacy rate of each COVID-19 vaccine authorized for use in the U.S. varies. The Pfizer-BioNTech vaccine is 95 percent effective at preventing symptomatic COVID-19 infections, the Moderna vaccine is 94.1 percent effective, and the Johnson & Johnson vaccine — the administration of which is currently on “pause” due to blood clotting concerns — is 66.3 percent effective.

“These vaccines are 95 percent effective at best,” Dr. William Schaffner, an infectious disease specialist and professor at Vanderbilt University School of Medicine, tells Yahoo Life. “These are wonderfully effective vaccines, but nothing in life is perfect — except maybe my wife.”

Dr. Thomas Russo, professor and chief of infectious disease at the University at Buffalo in New York, tells Yahoo Life that the findings are “not surprising” and points out that there is a difference between clinical trials and the real-world use of the vaccine. “Clinical trials excluded people who are immunocompromised, and those patients have immune systems that don’t function as well as people in the general population,” he says. As a result, the vaccine is often not as effective in them, Russo says.

Schaffner agrees. “We’re now vaccinating very, very frail people and people who are immunocompromised — you’re more likely to have breakthrough cases because their protection won’t be as complete as a normal healthy person’s protection is,” he says.

Worth noting: The CDC did not disclose details about the health of the people who had breakthrough infections.

But Russo says the news underscores the importance of continuing to follow COVID-19 prevention recommendations, regardless of your vaccination status. He stresses, though, that it doesn’t mean these protocols will be in place forever. “Masks and social distancing are still important in the community until more people are vaccinated,” he says. “Once we can get these cases down, we’re going to be able to step away from public health measures.”

Adalja says it’s smart for public health officials to track these breakthrough infections to try to get more answers. “It’s important to study the breakthrough cases to understand if the vaccine took in those individuals to better characterize this very low risk,” he says.

Ultimately, doctors urge people to stay calm and focus on the bigger picture. That is, the vaccine is highly effective at preventing COVID-19 infections in those who have been fully vaccinated. Breakthrough infections “didn’t happen in 99.93 percent of cases,” Adalja says.

“Don’t panic,” Schaffner says. “Everybody, please take a deep breath. Vaccines profoundly reduce your risk of getting an infection, but it’s not zero.”

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