Two or three COVID-19 vaccine doses provided 90% protection against invasive mechanical ventilation or in-hospital death among adults during the delta and omicron periods, according to new data released Friday from the Centers for Disease Control and Prevention.
The results may reassure long-term care clinicians and their patients, who have faced concerns about increased risk from severe illness, hospitalization and death since the omicron variant became predominant in January.
CDC investigators analyzed data on severe COVID-19 outcomes from a multistate hospital network. Adults who received a third vaccine dose had the highest level of protection, they found, “including 94% during the omicron period.”
Among patients who died despite being vaccinated, most were older or had comorbidities and many were immunosuppressed, they added.
Unvaxxed 12 times more likely to be hospitalized
Another study, also published Friday by the CDC, showed that hospitalizations rose for all adults in January when omicron was fully in force. But the unvaccinated were 12 times more likely to be hospitalized as those who received additional vaccination or booster doses, investigators found.
Booster shots, meanwhile, appeared to do their job of providing additional protection despite COVID-19 vaccines’ diminished effectiveness against the omicron variant. A primary series of vaccinations was protective, but adults who did not receive a booster jab had three times the odds of hospitalization than their peers who did, the researchers reported.
In another key finding, COVID-19 hospitalization rates in January increased at a higher rate among non-Hispanic Black adults than in other racial/ethnic groups.
The overall results highlight the effectiveness of COVID-19 vaccination, investigators said. They encouraged the public to stay on top of their shots and that clinicians support equitable receipt of COVID-19 vaccines among non-Hispanic Black populations.
