April 21, 2021


What we know about COVID-19 cases AFTER receiving the COVID-19 vaccine.

What Is "Breakthrough?"

“Vaccine breakthrough” – a case when a person tests positive for the SARS-CoV-2 virus (either by a PCR or rapid antigen test) more than two weeks after receiving a full series of a COVID-19 vaccine (either one or two doses, depending on the vaccine).

A case represents a TEST that’s positive, not necessarily someone who has symptoms.

The Details In Data

As of April 13th, 2021: 5,814 reports of breakthrough infection (CDC).

  • 55% under age 60
  • 65% female
  • 29% asymptomatic
  • 7% hospitalized (396 patients with *some* hospitalized for *a reason other* than COVID)
  • 1% died (of 74 people who died, 9 died of reasons OTHER than COVID)
"These vaccines are working."

CDC Director Dr. Walenksy says while the data is likely underestimating the number of breakthrough cases (in part because only 43 states and territories reported) she says the fact nearly 30% of the cases had no symptoms is “encouraging news,” saying that this shows the vaccines are helpful in preventing severe disease. The CDC Dir. says rare breakthrough cases are expected with any vaccine.

“If you’re asymptomatic and you are vaccinated, you would not be likely to be presenting to get tested.”

Associate professor of epidemiology Bill Hanage, Harvard T.H. Chan School of Public Health, explaining another reason why the number of “breakthrough” infections is likely an underestimate. Epidemiologists say as community spread decreases, so too will instances of breakthrough infections – while also warning no COVID-19 vaccine has 100% efficacy.

Unlike some other vaccines in use, such as the chickenpox vaccine, none of the vaccines approved for emergency use contain a LIVE coronavirus that would lead to a positive COVID-19 test. Questions remain over the rate at which a vaccinated individual potentially could still transmit the virus that causes COVID-19.

All the numbers: COVID-19 Breakthrough Case Investigations and Reporting

by Jenna Lee,