Nebraska omicron cluster suggests faster symptom onset compared to past Covid variants

The household members who were reinfected experienced fewer symptoms compared to their first infections in November 2020, according to the CDC. Two of them reported fevers after infection, none reported loss of taste or smell.

The unvaccinated individual who had not tested positive before experienced cough, joint pain, congestion, fever and chills. Nobody in the household required hospitalization after testing positive from omicron, and none of them had underlying health conditions or compromised immune systems. Those reinfected did not require hospitalization after their first infections in 2020 either.

The first confirmed case of omicron was reported on Dec. 1 in the San Francisco area by California public health authorities. The individual had returned from a trip to South Africa. However, the CDC subsequently found someone who reported symptoms on Nov. 15 after international travel, indicating that the variant could have arrived in the U.S. earlier.

Omicron was first identified by South Africa and Botswana in November. The variant now represents 58% of sequenced cases in the U.S. while delta makes up about 41% of cases, according to the CDC.

A growing body of data from South Africa and the United Kingdom indicates that people do not get as sick from omicron compared to the delta variant. The U.K. Health Security Agency found that people infected with omicron were 50 – 70% less likely to require hospitalization. South African scientists found that people infected with omicron were 70% less likely to develop severe disease.

However, the authors of the studies cautioned against reading too deeply into the preliminary data, because vaccination and immunity from prior infection could have influenced the findings.

Another study from the U.K. Health Security Agency found that a booster dose of Pfizer and BioNTech’s vaccine provides 75% protection against symptomatic disease from omicron. South African data suggests that two-doses of the Pfizer vaccine still protects against severe illness, but is much less effective at preventing omicron infection.

In the U.S., new Covid cases are surging to near pandemic highs. The nation reported an average of more than 237,000 daily new cases for the seven-day period ending Monday, up 66% over the past week, according to a CNBC analysis of data from Johns Hopkins University.

More than 70,000 people in the U.S. are currently hospitalized with Covid, up 3% over the past week, according to a seven-day average of data from the Health and Human Services Department as of Dec. 27.