Only a small percentage of the Omicron variant of COVID-19 cases require hospitalization so far, but high infectivity may turn this small percentage into a large number of patients, which will further stress our health care system.
Two new reports shed light on Omicron. The first is from the Norwegian Institute of Public Health. On November 26 2021, a Christmas party was held in Norway with 111 participants. Eighty individuals became infected with SARS-CoV-2. So far 17 are confirmed to be infected with the Omicron variant. Sequencing is ongoing but it is assumed that the majority of those infected have the Omicron variant. In addition, another 60 people who visited the restaurant became infected.
All but one participant reported symptoms. Most reported onset within 3 days. “Over 70% of cases reported cough, lethargy, headache, sore throat and over half of them reported fever. No hospital admissions have been reported.”
The vast majority of participants were vaccinated with a two-dose mRNA vaccine.
The second is from the Centers for Disease Control and Prevention (CDC), which described the initial 43 Omicron cases in the United States. Almost 80% (34) were fully vaccinated and 14 individuals had received a booster. Of these individuals one has been hospitalized and the rest had mild symptoms usually manifesting with coughing and lethargy.
The bottom line is that initial data from small studies indicates that vaccines and boosters protect against hospitalizations and death, but not infections. Overall, there is only a small percentage of cases which appear to require hospitalization.
However, the high infectivity of Omicron may turn this small percentage into a large number of patients, which risks further stressing our health care system. We need to remember that Omicron is not Delta becoming less virulent. It had a separate evolutionary pathway possibly originating in rodents. We should not be surprised if other widely different variants also appear. Presently, Delta is the major variant of concern in the United States but may be replaced by Omicron in a few weeks to months. Omicron appears to be able to spread easily among previously immune populations, and then seek out immunologically naïve individuals, possibly causing severe disease.
In the United Kingdom, it has been observed that the Omicron variant causes less severe disease, but it risks overwhelming their health care system with 5 thousand admissions to the hospital each day. Omicron currently is responsible for 30% of all cases in London.
Everyone needs to become vaccinated. Hopefully, each variant will add to a broadening of our immunological response and result in a progressive lessening of disease severity.