Virus World

(CNN)The United States' first confirmed case of the Omicron coronavirus variant has been identified in California. In a White House news briefing, Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said the case was in an individual who traveled from South Africa on November 22 and tested positive for Covid-19 on November 29.  That individual, Fauci said, is self-quarantining and close contacts have tested negative for the coronavirus so far. The person was fully vaccinated and is experiencing "mild symptoms, which are improving at this point," Fauci said.  Asked by CNN whether that person had a booster shot, Fauci said, "To my knowledge, no."

“We were surprised” by the study findings, Durstenfeld said in a statement. “We expected that Paxlovid would be associated with a lower prevalence of long COVID … but it is consistent with two other rigorously conducted studies finding no difference in post-COVID conditions between 4 and 6 months after infection.” Researchers selected a group of vaccinated people from UCSF’s COVID-19 Citizen Science Study who reported their first infection between March and August 2022, according to a UCSF news release. Among the 1,611 participants, the study shows the median age was 55 years and 66% were female.  Only some of the participants took oral Paxlovid treatment while they were infected. In December of that year, participants answered a survey about long COVID, rebound symptoms and test positivity, health officials said. From a group of individuals who reported feeling better while taking Paxlovid treatment, 21% reported rebound symptoms — 10.8% of whom reported one or more long COVID symptoms compared with 8.3% of individuals without rebound symptoms, the study found. For those who repeated testing after testing negative and completing treatment, 25.7% reported rebound test positivity again. In total, researchers said 26% said they rebounded or tested positive.

A similar study published in November found that viral rebound occurred in approximately 21% of Paxlovid recipients. “We found a higher proportion with clinical rebound than previously reported but did not identify an effect of post-treatment rebound on long COVID symptoms,” Durstenfeld said. Dr. Peter Chin-Hong, an infectious disease expert at UCSF who was not involved in the new study, said its findings are “not surprising at all” because the risk of long COVID among people who are vaccinated and in their 50s was low to begin with during the omicron spike. “This study helps us refine the population where you could have the biggest bang for the buck in Paxlovid,” Chin-Hong said. “It continues to be older or immunocompromised who are unvaccinated or whom there is not much of an immune response as in the severely immunocompromised.”

Reach Jessica Flores: jessica.flores@sfchronicle.com; Twitter: @jesssmflores

See study publisned in the Journal of Medical Virology (Jan.4. 4, 2024):

https://doi.org/10.1002/jmv.29333