Unvaccinated adults were 23 times more likely to be hospitalized with COVID-19 during the omicron wave than adults who were vaccinated and boosted, according to a new study that further highlights the importance of coronavirus vaccination and booster shots.
The study from the Centers for Disease Control and Prevention (CDC) found by far the highest rates of cases and hospitalizations among unvaccinated people, followed by vaccinated but not boosted people, with vaccinated and boosted people having the most protection.
The study used data from Los Angeles County as of Jan. 8, during the omicron wave.
Hospitalizations were 5.3 times higher among the unvaccinated than vaccinated but not boosted.
“Efforts to promote COVID-19 vaccination and boosters are critical to preventing COVID-19-associated hospitalizations and severe outcomes,” the study states.
While the largest effects were in reducing hospitalizations, the study also shows that vaccines and boosters lowered the chance of getting infected at all. The protection is not total, meaning there are still frequent breakthrough cases, but the severity is far lower among people who are vaccinated and boosted than among the unvaccinated.
Case rates among unvaccinated people were 3.6 times higher than vaccinated and boosted people, and two times higher than vaccinated and not boosted people, the study found.
The study also found that as expected, there was some dropoff in the performance of the vaccines against omicron compared with the delta variant, given omicron’s increased ability to evade protection.
Gaps between the unvaccinated and vaccinated were even larger with the delta variant, with a hospitalization rate 83 times higher for the unvaccinated compared to boosted people, and a case rate 12.3 times higher.
“Rate ratios indicated continued protection conferred by vaccine against severe disease, especially among those who had received a booster, although reduced for Omicron compared with Delta,” the study states.
Health officials are urging more people to get boosted. Right now, only about 44 percent of fully vaccinated adults are boosted, according to CDC data.