The US shows far fewer Covid-19 cases, hospitalizations and deaths in vaccinated people for multiple reasons: US data does not differentiate between individuals who have had one, two or three shots and the US a different definition for 'vaccinated'. Americans may be counted as unvaccinated if they have yet to take two doses of the mRNA vaccine. Individuals are counted as unvaccinated if less than two weeks has passed since they took a Covid vaccine. People may be counted as unvaccinated if their vaccine status is unknown upon admission into hospital.

In addition, the CDC has withheld large swaths of data. The CDC omitted data on the hospitalization rate for booster shots in people 18 to 49, and a spokesperson said that it was "not yet ready for prime time" and that the information might be misinterpreted.

Health and Human Services (HHS) no longer requires hospitals to report deaths from COVID-19.