The U.S. Centers for Disease Control and Prevention has identified a small cohort of about 5,800 cases of Covid-19 infection among more than 66 million Americans who have completed a full course of vaccinations.
These so-called discovery cases, which are defined as positive results of the Covid-19 test received at least two weeks after patients receive the final dose of vaccine, represent 0.008% of the fully vaccinated population.
Officials said such cases are in line with expectations, as US-approved vaccines are extremely effective but not 100% infallible. They remind that even vaccinated people are at risk and should continue to take precautions such as masking and social distancing in many circumstances.
The CDC earlier this year called on state health departments to track and report cases of discovery to the federal government. To date, the reported cases come from about 40 states.
Separately, the Wall Street Journal contacted health departments in all 50 states and the District of Columbia to ask how many cases of discovery were identified. Twenty-three states responded, reporting a total of 4,172 discovery cases.