Government COVID-19 data shows that people who are fully vaccinated against COVID-19 can still get infected. That data shows infections occur rarely, even with the rise of the highly transmissible Delta variant. However, several issues make it challenging to assess the accuracy of those numbers.
First, in May, the Centers for Disease Control and Prevention (CDC) stopped tracking all reported breakthrough cases that don’t result in death or hospitalization. Second, for breakthrough cases to show up in any dataset, vaccinated people need to get tested if they think they contracted the virus. There isn’t a government data set or survey that measured the likelihood vaccinated people would get a test if they were symptomatic.
The CDC defines breakthrough cases as the detection of COVID-19 in someone more than two weeks after completing vaccination, whether it’s a two-shot Pfizer or Moderna vaccine or the single-shot Johnson and Johnson vaccine. From January 1 to April 30, there were 10,262 breakthrough cases across 46 states and territories. With 101.4 million people fully vaccinated by that point, 0.01% of fully vaccinated people had contracted COVID-19. But this data was from before the Delta variant took hold in most of the US.
