How bad is Omicron? That question is riveting scientists and policymakers as the latest coronavirus variant rampages across the world. We know for sure that it is much, much more contagious than previous variants, given how it has gotten loose in countries like Australia that previously managed to halt transmission entirely. But how about the severity of the illness it causes?
On the one hand, it is known with reasonable certainty that Omicron will cause less severe illness. A preprint study in The Lancet recently measured the first month of the Omicron wave in Gauteng province in South Africa against the same period of the Beta and Delta waves, so as to get an apples-to-apples comparison. They found that while there were vastly more cases in the Omicron wave, a far smaller share were hospitalized (4.9 percent versus 18.9 percent for Beta and 13.7 percent Delta) and of those hospitalizations, a much smaller share had severe symptoms (28.8 percent versus 60.1 percent and 66.9 percent, respectively). However, a much larger share of Omicron hospitalizations were children this time, probably because of very limited vaccination in that group.
Again, this has not been peer-reviewed yet, but it fits with reported coverage as well as South African statistics.
A large portion of this difference between Omicron and Delta is certainly because of widespread population immunity. The vast majority of South Africans have had a coronavirus infection already, plus about 31 percent have at least one dose of vaccine. While Omicron is often getting around natural immunity or vaccination (get boosted!), that still means milder illness in general.
But some of the difference is probably also because Omicron is inherently less severe. Several pre-print animal studies suggest that the mutations that make it so incredibly contagious and evasive to prior immunity also make it less able to infect the lungs — where the previous variants wreaked their worst havoc.
That is all to the good. But increased contagiousness can compensate for that lessened severity with sheer numbers of infections. Sure enough, across the United States, the staggeringly rapid spread of Omicron is swamping clinics and hospitals that were already reeling from two years of nearly nonstop pandemic. Burnout, post-traumatic stress disorder, and simple exhaustion have badly eroded the ranks of medical staff, and thousands of them have also caught Omicron. The remainder are dealing with yet another surge of patients — some of whom are prone to assaulting workers.
It would be a good idea to hunker down and avoid the emergency room if at all possible for about the next 6 to 8 weeks.