The amount of people experiencing rare breakthrough COVID-19 infections will increase as more transmissible variants spread across the country, but health experts aren't alarmed, NPR reported July 21.
"I haven't seen any signals in the U.S. indicating that they are occurring at the levels that would give us concern that the [vaccine] effectiveness is going down," Saad Omer, PhD, director of the Yale Institute for Global Health in New Haven, Conn., told the publication.
Seven takeaways:
1. Breakthrough COVID-19 infections are a rare, but expected occurrence, as no vaccine is 100 percent effective.
2. The vast majority of breakthrough infections are mild and "tend to be more like a cold," said Carlos del Rio, MD, professor of medicine and infectious disease epidemiology at Emory University in Atlanta.
3. As of July 12, there have been 5,492 reports of breakthrough cases involving hospitalization or death among more than 159 million Americans vaccinated, according to the CDC.
4. About 75 percent of cases occurred in people aged 65 or older, and 19 percent resulted in death.
5. Among the 5,189 people who required hospitalization, 28 percent were asymptomatic or admitted for a different health issue.
6. The delta variant's rapid spread in the U.S. will lead to more cases among vaccinated and unvaccinated people, according to John Moore, PhD, professor of microbiology and immunology at Weill Cornell Medicine in New York City.
"But its ability to infect fully vaccinated people is much less than those who are not vaccinated," he told NPR.
7. At present, there is no clear data showing delta is responsible for a major rise in breakthrough cases, according to Emily Martin, PhD, an epidemiology professor at the University of Michigan in Ann Arbor.