The highly contagious omicron variant of the COVID-19 virus often does an end run around the immunological protections of vaccination or prior infection. But recent data from the U.K. and Canada indicate that these breakthrough omicron infections are much less dangerous than first-time infections in unvaccinated people.
Ontario public health authorities report that as of yesterday, 2,093 and 288 people are being treated for omicron variant infections in hospitals and intensive care units (ICUs), respectively. The hospitalization rate per million among unvaccinated people stands at 532.7; it's 105.9 for folks vaccinated with at least two doses. This means that the reduction of hospitalization risk for those inoculated with at least two doses is 80.1 percent.
The ICU occupancy rate per million is 135.6 for unvaccinated people and just 9.2 for those who have gotten two doses of COVID-19 vaccines. So vaccination reduces the ICU risk by 93.2 percent.
An analysis by the United Kingdom Health Security Agency (UKHSA) similarly found that "the risk of being admitted to hospital for Omicron cases was lower for those who had received 2 doses of a vaccine (65% lower) compared to those who had not received any vaccination." The risk "was lower still among those who had received 3 doses of vaccine (81% lower)."
The UKHSA report also parses the effectiveness of the vaccines against both the delta and omicron variants. Two vaccine doses essentially maintain their effectiveness against the delta variant over time, but protection against the omicron variant wanes fast. That said, a third shot significantly boosts the immune system's ability to fend off and reduce the severity of omicron infections for about 3 months. The good news is that the vaccines' protection against hospitalization is much greater than their protection against symptomatic disease. And with a booster dose, vaccine effectiveness against hospitalization is close to 90 percent.
These British and Canadian findings mirror those most recently reported by the New York State Health Department. It finds that the daily rate per 100,000 of COVID-19 hospitalizations stands at 4.56 for fully vaccinated people, compared to 58.27 for unvaccinated people. That means vaccinations are 92.3 percent effective at preventing hospitalization from COVID-19.
Other data from around the U.S. are in line with these findings. For example, in Greenville, North Carolina, The Daily Reflector reports that out of the 120 COVID-positive inpatients at Vidant Health hospitals, 101 had not been vaccinated; 30 out of the 34 COVID ICU patients were not vaccinated. Similarly, Block Club Chicago reports that 85 percent of people hospitalized for COVID in Illinois—and 90 percent admitted to ICUs—are unvaccinated. In Louisiana, the state health department says that 76 percent of the people hospitalized for COVID-19 infections were unvaccinated. In the Baystate Health system in Massachusetts, around 70 percent of COVID-19 patients are unvaccinated.
Some good news for both the vaccinated and the unvaccinated is that the omicron variant seems to cause less severe disease than earlier versions of COVID-19. Still, given the steep rise in the omicron wave, it would be wise for the medically eligible unvaccinated to now take responsibility to protect themselves, their families, their friends, and their fellow Americans by getting their shots.