Healthcare staff put together Covid-19 checks at a Nomi Health testing web site in Omaha, Nebraska, on Wednesday, Nov. 10, 2021.
Dan Brouillette | Bloomberg | Getty Images
An investigation right into a cluster of omicron infections in Nebraska suggests the closely mutated variant has a shorter incubation interval and causes comparable or milder signs in comparison with previous variants for people who find themselves vaccinated or beforehand contaminated, in line with the U.S. Centers for Disease Control and Prevention.
The CDC on Tuesday launched findings from an epidemiological investigation into six omicron instances confirmed from a single family in Nebraska.
A 48-year-old man who returned to the U.S. on Nov. 23 from a convention in Nigeria skilled signs a day later and examined optimistic for the virus on Nov. 26. The man, who was unvaccinated and had a previous historical past of symptomatic an infection in 2020, reported he was not sporting a masks when he had shut contact with a masked particular person who was coughing on the worldwide convention on Nov. 20.
The man took an antigen take a look at earlier than returning to the U.S. and the outcomes got here again damaging on Nov. 21. Upon his return to the U.S., he was nonetheless asymptomatic and had shut contact with 5 members of his family in Nebraska with out sporting a masks on Nov. 23.
The 5 members of his family, not less than considered one of whom was as younger as 11 years outdated, developed signs from Nov. 24 – 26 and subsequently examined optimistic. Four of them had prior histories of symptomatic an infection in 2020, considered one of whom was absolutely vaccinated with two Pfizer doses.
Another particular person within the family was unvaccinated and had by no means examined optimistic for Covid earlier than. However, that individual did have gentle higher respiratory signs in November 2020 earlier than the opposite members of the family first received contaminated.
The CDC stated it took 33 to 75 hours, a median of about 3 days, for family members to point out signs after publicity to the person who travelled, suggesting a shorter incubation interval with omicron. The median incubation interval for Covid is 5 days or extra, whereas the delta variant usually takes about 4 days for signs to point out, in line with the CDC.
The family members who have been reinfected skilled fewer signs in comparison with their first infections in November 2020, in line with the CDC. Two of them reported fevers after an infection, none reported lack of style or scent.
The unvaccinated particular person who had not examined optimistic earlier than skilled cough, joint ache, congestion, fever and chills. Nobody within the family required hospitalization after testing optimistic from omicron, and none of them had underlying well being circumstances or compromised immune techniques. Those reinfected didn’t require hospitalization after their first infections in 2020 both.
The first confirmed case of omicron was reported on Dec. 1 within the San Francisco space by California public well being authorities. The particular person had returned from a visit to South Africa. However, the CDC subsequently discovered somebody who reported signs on Nov. 15 after worldwide journey, indicating that the variant may have arrived within the U.S. earlier.
Omicron was first recognized by South Africa and Botswana in November. The variant now represents 58% of sequenced instances within the U.S. whereas delta makes up about 41% of instances, in line with the CDC.
A rising physique of information from South Africa and the United Kingdom signifies that individuals don’t get as sick from omicron in comparison with the delta variant. The U.Okay. Health Security Agency discovered that individuals contaminated with omicron have been 50 – 70% much less more likely to require hospitalization. South African scientists discovered that individuals contaminated with omicron have been 70% much less more likely to develop extreme illness.
However, the authors of the research cautioned towards studying too deeply into the preliminary information, as a result of vaccination and immunity from prior an infection may have influenced the findings.
Another research from the U.Okay. Health Security Agency discovered {that a} booster dose of Pfizer and BioNTech’s vaccine gives 75% safety towards symptomatic illness from omicron. South African information means that two-doses of the Pfizer vaccine nonetheless protects towards extreme sickness, however is way much less efficient at stopping omicron an infection.
In the U.S., new Covid instances are surging to close pandemic highs. The nation reported a mean of greater than 237,000 each day new instances for the seven-day interval ending Monday, up 66% over the previous week, in line with a CNBC evaluation of information from Johns Hopkins University.
More than 70,000 folks within the U.S. are presently hospitalized with Covid, up 3% over the previous week, in line with a seven-day common of information from the Health and Human Services Department as of Dec. 27.