https://www.cnn.com/2021/04/14/health/breakthrough-infections-covid-vaccines-cdc/index.html CDC will be looking for clues about who is most prone to become infected despite having been vaccinated. "Vaccine breakthrough infections were reported among all people of all ages eligible for vaccination. However, a little over 40% of the infections were in people 60 or more years of age," the CDC said. CDC: 'IF WE STOP COUNTING IT, IT DIDN'T HAPPEN OR AT LEAST WILL IMPROVE OUR STATISTICS' https://www.cdc.gov/vaccines/covid-19/health-departments/breakthrough-cases.html As of May 1, 2021, CDC transitioned from monitoring all reported vaccine breakthrough cases to focus on identifying and investigating only hospitalized or fatal cases due to any cause. This shift will help maximize the quality of the data collected on cases of greatest clinical and public health importance. Previous case counts, which were last updated on April 26, 2021, are available for reference only and will not be updated moving forward.