The U.S. reached a vaccination milestone this week, with 50% of the adult population being fully vaccinated; with that, infection rates have been dropping and the vaccine appears to be lowering the spread of the virus.
While no vaccine is 100% effective, the CDC says the percentage of fully-vaccinated Americans who are contracting the coronavirus, so-called breakthrough cases, is about .01%.
Fully-vaccinated refers to someone who is two weeks past their second shot of the Pfizer or Moderna COVID-19 vaccine, or two weeks after getting the single-shot Johnson & Johnson vaccine.
The CDC report looked at roughly 10,200 breakthrough cases reported to the health agency since vaccinations began.
It showed breakthrough cases are very rare, and that the vaccines are doing their job of protecting people from the most serious symptoms of the virus if they do contract it after vaccination.
Of those who tested positive for the coronavirus after vaccination, about 160 people, or roughly 2%, died. The CDC says 28 of the deaths included in their report were unrelated to COVID-19, but the agency did not provide more details.
More than 60% of the breakthrough cases were reported in women, and a majority of the cases were in people between the ages of 40 and 74.
Researchers with the CDC caution that the number of breakthrough cases in their report may be an undercount. Starting May 1, the agency started focusing only on breakthrough cases that result in hospitalization or death. Also, those who are fully vaccinated are likely being tested for COVID-19 less, and therefore if they have contracted the virus and do not have symptoms, they may not know.