Adult fully vaccinated against COVID-19 rarely die from the disease, although the odds of severe outcomes and death are higher in older adults and in those with compromised immune systems and underlying conditions.
According to the experts, vaccination against COVID-19 is highly effective at preventing COVID-19–associated hospitalisation and death, however, some vaccinated individuals may develop COVID-19 with severe outcomes.
Using data from 465 centres in a large US healthcare database, researchers analysed the frequency of and risk factors for severe COVID-19 outcomes among adults who completed a primary vaccination series, defined as at least 2 weeks after receiving the second dose of either Pfizer-BioNTech or Moderna vaccine) or one dose of the Johnson & Johnson COVID-19 vaccine.
Severe COVID-19–associated outcomes and death were rare following primary vaccination, according to Dr. Christina Yek, with the National Institutes of Health and colleagues with the US Centres for Disease Control and Prevention COVID-19 Response Team.
The study published in the CDC’s Morbidity and Mortality Weekly Report stated that among 1.2 million adults who completed primary vaccination during December 2020 and October 2021, 2,246 developed COVID-19, and 189 had a severe outcome, including 36 who had a COVID-19–related death.
The findings are relevant to infections during periods of pre-Delta or the Delta variant and might not be applicable to the risk from the Omicron.
They however warned that people with immune dysfunction are at increased risk for COVID-19 breakthrough infection after vaccination, and should take additional precautions.