— Study examines which factors did, and didn’t, play a role in risk
A significant proportion of all fully vaccinated adults who died of COVID-19 had at least four risk factors associated with severe outcomes, researchers found.
In addition to older age (65 and up) and being immunosuppressed, having chronic kidney, cardiac, pulmonary, neurologic, or liver diseases, as well as diabetes, were all associated with higher odds of severe COVID outcomes, and 77.8% of fully vaccinated adults who died had at least four of these risk factors, reported Sameer Kadri, MD, of the NIH Clinical Center in Bethesda, Maryland, and colleagues in the Morbidity and Mortality Weekly Report.
However, there were no increased odds of severe outcomes associated with sex, race/ethnicity, time since primary vaccination, or whether the infection occurred during the Delta variant wave.
Kadri and team examined data from 465 U.S. healthcare facilities in the Premier Healthcare Database Special COVID-19 Release from December 2020 to October 2021, which included adults who were either fully vaccinated, received a third dose as part of their primary series, or received a booster dose after their primary series. Severe outcomes were defined as hospitalization with acute respiratory failure, non-invasive ventilation, ICU admission, and death.
Overall, 1,228,664 adults completed a primary vaccination series, and of those, 2,246 contracted COVID-19. Of these, 327 were hospitalized, 189 had a severe outcome, and 36 had a COVID-related death.
Not surprisingly, older age was associated with a higher risk of death (adjusted OR [aOR] 3.22, 95% CI 1.81-5.74), as was immunosuppression (aOR 1.91, 95% CI 1.37-2.66).
Of the six conditions, chronic pulmonary disease (aOR 1.69, 95% CI 1.31-2.18), liver disease (aOR 1.68, 95% CI 1.12-2.52), and kidney disease (aOR 1.61, 95% CI 1.19-2.19) were associated with the highest odds of severe outcomes.
Interestingly, Pfizer vaccine recipients had comparable risks of severe outcomes to those who received the Johnson & Johnson vaccine (aOR 0.70, 95% CI 0.39-1.26), while these risks were lower for those who received Moderna (aOR 0.56, 95% CI 0.32-0.98).
Kadri and colleagues noted that all adults with severe COVID outcomes had at least one of the eight risk factors. Only 19% of all adults with four or more risk factors had non-severe outcomes, while 57% had respiratory failure or were admitted to an ICU.
Among 36 adults who died, 15 had do-not-resuscitate orders at the time of hospital admission, and nine were discharged to hospice.
The authors noted that these results may not be applicable to time periods when other variants were predominant in the U.S.