Paxlovid tied to fewer COVID-19 hospitalizations, reduced risk of long COVID

News brief

A new retrospective cohort study conducted in Dubai shows that the antiviral nirmatrelvir plus ritonavir, sold as Paxlovid, is tied to a 61% reduction in COVID-19 hospitalization and a 58% lower rate of long COVID.

The study was published today in Scientific Reports and adds to the understand of the usefulness of Paxlovid in the Omicron-variant period.

Using electronic health records from the Dubai Health Authority (DHA) hospitals and clinics in the United Arab Emirates, the authors of the study compared outcomes of patients who received Paxlovid to those who did not receive any antiviral treatment for COVID-19 seen from May 22, 2022, to April 30, 2023, at any DHA-affiliated hospitals and clinics.

The study defined long COVID as continuous or new symptoms present 28 days or more following acute COVID-19 infection, based on physician notes.

In total 7,290 non-hospitalized adult COVID-19 visits, including 672 patients who received Paxlovid and 6,618 patients who received no antiviral treatment, were included in the study. Almost half of the patients in both groups had received two doses of the COVID-19 mRNA vaccine (45% in the Paxlovid group, and 48% in the no-treatment group), the authors said.

1.1% in Paxlovid group hospitalized

A total of 170 (2.3%) COVID-19-related hospitalizations lasting more than 1 day were observed over a 28-day period. These included 8 (1.1%) in the nirmatrelvir-ritonavir group and 162 (2.4%) in the no-treatment group.

After adjusting for factors, Paxlovid was associated with a 61% lower risk of hospitalization (adjusted hazard ratio [aHR], 0.39; 95% confidence interval [CI], 0.18 to 0.85).

During a 90-day follow up, 208 patients (2.8%) experienced long-COVID symptoms that prompted them to see a physician. Paxlovid was associated with a 58% reduced risk of developing such symptoms during that period (aHR. 0.42; 95% CI, 0.19 to 0.95).

Given that the most common variant during our study was Omicron (BA.4/5), this suggests the efficacy of the treatment against these variants of SARS-CoV-2.

"Given that the most common variant during our study was Omicron (BA.4/5), this suggests the efficacy of the treatment against these variants of SARS-CoV-2," the authors wrote.

More human avian flu cases in Washington state, California

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Stephanie Soucheray, MA

dairy worker — Guillermo Spelucin Runciman / iStock

The Centers for Disease Control and Prevention (CDC) said there are 6 confirmed human cases of H5 avian flu in Washington state, as well as 3 more cases in California, raising the national total of human cases to 36 in the United States.

In both Washington and California, the new cases have occurred in workers on affected farms.

"The farm workers in California and Washington state all described mild symptoms, many with eye redness or discharge (conjunctivitis). Some cases in Washington reported some mild upper respiratory symptoms," the CDC said in an update.

The farm workers in California and Washington state all described mild symptoms, many with eye redness or discharge.

So far 15 of the human cases have been associated with exposure to H5N1-infected poultry, and 20 have been associated with exposure to sick or infected dairy cows. One case in Missouri has an unknown exposure source. Serologic testing of case contacts in Missouri shows no signs of human-to-human spread.

In related news, the US Department of Agriculture Animal and Plant Health Inspection Service has confirmed 8 more H5N1 detections in California dairy cattle, raising the state's total to 186 and the national total to 388 affected herds.