The Union Democrat
About 1 in 5 Paxlovid users experience rebound symptoms, study finds
President Biden this week reiterated the promise that most Americans will only need to receive an annual booster shot against COVID-19, despite widespread skepticism from infectious disease experts who think waning vaccine efficacy will necessitate more than one dose every 12 months. In California, Yosemite National Park officials have announced that the contentious reservation requirement enacted during the pandemic will not be in place next year.
About 1 in 5 Paxlovid users experience rebound symptoms, STUDY FINDS
About 19% of COVID-19 patients who used the oral antiviral Paxlovid experienced symptoms of a rebound infection, according to a preprint paper published Tuesday by researchers at Scripps Research Transitional Institute. In the study conducted between Aug. 4 and Nov. 1, 2022, the team tracked the progress of 170 study participants completed the 16-day procedures, with 127 in the Paxlovid treatment group and 43 in the control group. The results showed that viral rebound incidence was 14.2% in the Paxlovid group and 9.3% in the control group, while COVID-19 symptom rebound incidence was higher in the Paxlovid group (18.9%) compared to the control group (7.0%). The researchers found that age, gender, and pre-existing conditions did not play a role in increased incidence.
“This preliminary report of our prospective study suggests that rebound after clearance of test positivity or symptom resolution is higher than previously reported,” the authors wrote. “However, we observed a similar rate of rebound in both in the Paxlovid and control groups. Large studies with diverse participants and extended followup are needed to better understand the rebound phenomena.”
A clinical trial by drug manufacturer Pfizer showed that Paxlovid could reduce the risk of hospitalization and death from COVID-19 by 89%. The antiviral was made available under an emergency use authorization from the U.S. Food and Drug Administration in December 2021. Pfizer’s trial estimated that about 1% of users experience rebound symptoms. Infectious disease experts believe rebound of COVID-19 symptoms following a full five-day course of Paxlovid treatment is likely due to insufficient drug exposure, according to research by UCSF.
Newer variants cause more symptoms and greater disruption, STUDY FINDS
Newer coronavirus variants cause a wider variety of symptoms than their predecessors, according to a new study from Imperial College London. Researchers tracked transmission and symptoms among more than 1.5 million randomly selected adults, including 17,448 COVID-19 patients, from May 2020 to March 2022. About 76% of the patients who were infected with BA.2, the dominant variant at the time the study concluded, reported at least one of 26 symptoms, compared with 70% of those infected with BA.1, 63.8% of those with delta, 54.7% with alpha, and 45% with the original wild-type strain. “Contrary to the perception that recent variants have become successively milder, omicron BA.2 was associated with reporting more symptoms, with greater disruption to daily activities, than BA.1,” the authors wrote.
At least 17.6% of the people infected with BA.2 said their symptoms impacted their ability to complete daily activities “a lot,” compared with 10.7% of those infected with BA.1 and 10.5% with delta. “With restrictions lifted and routine testing limited in many countries, monitoring the changing symptom profiles associated with SARS-COV-2 infection and effects on daily activities will become increasingly important,” they said.