In a study led by MedUni Vienna, data from more than 100,000 patients with a confirmed SARS-CoV-2 infection who were registered with the Vienna City Health Service around two years ago was analysed. Of these, more than 20,000 patients were treated with antiviral drugs due to their risk of a severe course. The investigations showed that the active ingredient combination nirmatrelvir-ritonavir can significantly reduce the risk of hospitalisation or premature death. The study results were recently published in the journal "Clinical Microbiology and Infection".
The research team led by Markus Zeitlinger and Anselm Jorda (Department of Clinical Pharmacology at MedUni Vienna) analysed a total of 113,399 cases of adult, non-hospitalised SARS-CoV-2 patients. Data from 90,481 untreated patients, 12,166 people taking nirmatrelvir-ritonavir and 10,752 molnupiravir users were compared. Nirmatrelvir-ritonavir and molnupiravir are oral antivirals that are or were part of the standard treatment for COVID-19 in non-hospitalised adults at increased risk of severe progression. More than 96 per cent of the people examined in the observation period from January 2022 to May 2023 were already immunised through a previous infection or vaccination. Omicron variants dominated the incidence of infection during this period, SARS-CoV-2 infections were notifiable. The aim of the research was to investigate the previously unclear "real effectiveness", i.e. the influence of the medication on hospitalisation and mortality, within 28 days of diagnosis.
Patients over 60 benefit more
The analysis showed that the risk of hospitalisation and premature death was significantly lower in patients aged 60 and over who were treated with nirmatrelvir-ritonavir than in untreated control subjects. "These effects were only found in older patients, however, and not in people under the age of 60,"reports first author Anselm Jorda. One possible reason why the active ingredient combination commonly known under its brand name Paxlovid is less effective in younger people could be that "younger, vaccinated people rarely fall so seriously ill that they have to be hospitalised," adds study leader Markus Zeitlinger. The active substance molnupiravir, which was also approved for the treatment of COVID-19 during the study period, did not show any statistically significant advantages in terms of reducing hospitalisations and mortality in the study. Molnupiravir has since been withdrawn from the market, which once again proves to be ’sensible’ in view of the study results, as Zeitlinger says.
The study demonstrates the real-world efficacy of the oral antiviral drug nirmatrelvir-ritonavir in non-hospitalised over-60s with COVID-19 in an omicron-dominated period. For the first time, Austrian data was analysed on a large scale. "Everything points to the fact that the results also apply to the currently prevalent virus variants KP.3.1.1. and XEC, especially as these are omicron subtypes," says Markus Zeitlinger. Further research should help to determine even more precisely which groups of patients will benefit from antiviral treatment.
Publication: Clinical Microbiology and Infection
Real-world effectiveness of nirmatrelvir-ritonavir and molnupiravir in non-hospitalised adults with Covid-19: a population-based, retrospective cohort study cohort study
Anselm Jorda, Dominik Ensle, Hubert Eser, Florentin Glötzl, Benjamin Riedl, Marton Szell, Arschang Valipour, Alexander Zoufaly, Christoph Wenisch, Doris Haider, Heinz Burgmann, Florian Thalhammer, Florian Götzinger, Bernd Jilma, Robin Ristl, Ursula Karnthaler, Markus Zeitlinger
https://doi.org/10.1016/j.cmi.2024.10.026
