U.S. Centers for Disease Control and Prevention has identified a small cohort of approximately 5,800 cases of Covid-19 infection among more than 66 million Americans who have completed a full course of vaccination.
These so-called advanced cases, which are defined as positive results from Covid-19 tests received at least two weeks after patients receive their final dose of vaccine, represent 0.008% of the fully vaccinated population.
Officials said these cases meet expectations because U.S.-approved vaccines are highly effective, but not 100% infallible. They recall that even vaccinated people are at risk and that they should continue to take precautions such as masking and social distancing in many circumstances.
Earlier this year, the CDC asked state health departments to follow up and report cases of progress to the federal government. So far, the reported cases come from about 40 states.
Separately, the Wall Street Journal contacted the health departments of the 50 states and the District of Columbia to ask them how many advanced cases had been identified. Twenty-three states responded, reporting a total of 4,172 advanced cases.