According to a study published in the journal Infectious Diseases, "Covid rebound," in which evidence of the illness disappears and then returns days or weeks later, was surprisingly common, even among patients who did not take the antiviral Paxlovid.

The antiviral medication Paxlovid from Pfizer consists of co-packaged tablets of nirmatrelvir and ritonavir for oral use. Paxlovid has been proven in clinical trials to nearly 90% lessen the likelihood that a person at risk of severe COVID-19 would need to be hospitalized when compared to a placebo. The US Food and Drug Administration (FDA) approved it for emergency use in late 2021. However, in 2022, the medical literature began to record cases of COVID-19 comebacks.

According to the findings of the new study, rebound after clearance of SARS-CoV-2 test positivity or COVID-19 symptom resolution is more common than previously reported in both treated and untreated patients. In the study, the researchers offered a COVID test kit to the study participants to check if they had a verified positive test. Each participant was asked to take a test and fill out a symptom questionnaire every other day for 16 days.

The researchers then compared the rates of rebound for those who chose to take Paxlovid vs. those who did not. A positive test result following a negative test or a reported recurrence of symptoms following symptom relief was used to measure rebound. There were 127 participants in the Paxlovid treated group and 43 participants in the control group for this early analysis.

The Paxlovid group experienced rebounds in both the antigen test and symptom categories at a higher rate, i.e., 14.2% vs. 9.3% for antigen test rebounds and 18.9% vs. 7.0% for symptom rebounds, respectively. The researchers concluded that the rebound rates for both the treated and untreated groups were higher than those reported in earlier research. 

(Source: https://www.daijiworld.com/news/newsDisplay?newsID=1056555 )