In late 2021, there was a global resurgence of coronavirus disease 2019 (COVID-19) due to the onset of the Omicron variant of the highly acute acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Omicron had surpassed the Delta variant by the end of December 2021. By early January, Omicron had spread widely around the world, even in places with high levels of pre-existing immunity.
Study: Oral Nirmatrelvir and severe Covid-19 results during Omicron Surge. Image credit: Cryptographer / Shutterstock
Fund
On December 22, 2021, the Food and Drug Administration (FDA) granted an emergency use authorization (US) for oral antiviral nirmatrelvir to treat mild to moderate COVID-19 in patients at increased risk of developing serious illness. The typical nirmatrelvir regimen consists of five consecutive days of treatment after a positive diagnosis of COVID-19. The US FDA relied on the randomized, double-blind, placebo-controlled trial of the evaluation of protease inhibition for COVID-19 in high-risk patients (EPIC-HR), which to analyze nirmatrelvir treatment in non-hospitalized high-risk patients, symptomatic adults with COVID-19.
In a recent study published in the Research Square * prepress server, researchers evaluated the effectiveness of nirmatrelvir in preventing COVID-19-associated death and hospitalization in high-risk patients.
About the study
This study used data from the computerized medical records of Clalit Health Services (CHS), a large health care institution that serves approximately half of Israel’s population, including nearly two-thirds of the elderly. The trial began on January 9, 2022 and ended on March 10, 2022, the first day medication was given to patients with CHS. Patients diagnosed with COVID-19 on February 24, 2022 were eligible to participate in the study.
Discoveries
A total of 109,213 people met the inclusion criteria for the study. The mean age of study participants was 60 years, with 39% of participants. Obesity, diabetes, and smoking were the most common comorbid conditions. COVID-19 immunity was present in 78% of patients, either through previous infection, vaccination, or hybrid immunity.
During the study period, 3,939 patients in the global population group received at least one dose of nirmatrelvir treatment. Participants age 65 and older and newly diagnosed with cancer had a significantly higher uptake. Participants without pre-existing vaccination against COVID-19 and members of the Arab minority group had significantly reduced absorption.
The author reports the results for the age groups over 65 and under 65 separately because the test of the interaction of nirmatrelvir status with other variables showed significant differences by age group.
COVID-19-associated hospitalizations occurred in 343 of the 1,435 treated patients and 334 of the 64,959 untreated patients among the 66,394 patients aged 40 to 64 years. COVID-19-associated hospitalizations occurred in 776 of 42,819 patients aged 165 years and older. of 2,504 treated patients, and 762 of 40,315 untreated patients. Reduced levels of COVID-19 immunity and prior hospitalization were the characteristics most substantially related to a high incidence of COVID-19-related hospitalizations in both age groups. Between the ages of 40 and 64, immunosuppression was strongly related to hospitalizations.
COVID-19-associated hospitalizations were reported in 182 of 20,531 patients without prior immunity and 161 of 45,863 patients with previous immunity in patients aged 40 to 64 years. COVID-19-associated hospitalization was reported in 273 of 3,306 patients without prior immunity and 503 of 39,513 patients with prior immunity among participants 65 years of age or older.
Implications
During the increase in the Omicron variant, medication with nirmatrelvir was associated with a substantial drop in COVID-19 hospitalizations and mortality rates in people 65 years of age and older. Although this was an observational study, the findings and the apparent potential to prevent severe COVID-19 could help decision makers to allocate limited supplies to those for whom nirmatrelvir has been shown to be successful.
* Important news
Research Square publishes preliminary scientific reports that are not peer-reviewed and therefore should not be considered conclusive, guided by clinical practice or health-related behavior, or treated as established information.