Clinical Effectiveness of Ritonavir-Boosted Nirmatrelvir-A Literature Review

Highlights What are the main findings? Nirmatrelvir/Ritonavir, an oral treatment for COVID-19, effectively reduces the risk of progressing to a more severe disease state for both the Delta and subsequent Omicron variants. Unvaccinated COVID-19 patients benefit more from a Nirmatrelvir/Ritonavir prescription than vaccinated ones. What is the implication of the main finding? Although effective at reducing the risk of progressing to a more severe disease state, Nirmatrelvir/Ritonavir cannot replace vaccinations. Future subanalyses should focus on pinpointing the role of age, strain, or comorbidities in effectiveness differences.Highlights What are the main findings? Nirmatrelvir/Ritonavir, an oral treatment for COVID-19, effectively reduces the risk of progressing to a more severe disease state for both the Delta and subsequent Omicron variants. Unvaccinated COVID-19 patients benefit more from a Nirmatrelvir/Ritonavir prescription than vaccinated ones. What is the implication of the main finding? Although effective at reducing the risk of progressing to a more severe disease state, Nirmatrelvir/Ritonavir cannot replace vaccinations. Future subanalyses should focus on pinpointing the role of age, strain, or comorbidities in effectiveness differences.Abstract Nirmatrelvir/Ritonavir is an oral treatment for mild to moderate COVID-19 cases with a high risk for a severe course of the disease. For this paper, a comprehensive literature review was performed, leading to a summary of currently available data on Nirmatrelvir/Ritonavir's ability to reduce the risk of progressing to a severe disease state. Herein, the focus lies on publications that include comparisons between patients receiving Nirmatrelvir/Ritonavir and a control group. The findings can be summarized as follows: Data from the time when the Delta-variant was dominant show that Nirmatrelvir/Ritonavir reduced the risk of hospitalization or death by 88.9% for unvaccinated, non-hospitalized high-risk individuals. Data from the time when the Omicron variant was dominant found decreased relative risk reductions for various vaccination statuses: between 26% and 65% for hospitalization. The presented papers that differentiate between unvaccinated and vaccinated individuals agree that unvaccinated patients benefit more from treatment with Nirmatrelvir/Ritonavir. However, when it comes to the dependency of potential on age and comorbidities, further studies are necessary. From the available data, one can conclude that Nirmatrelvir/Ritonavir cannot substitute vaccinations; however, its low manufacturing cost and easy administration make it a valuable tool in fighting COVID-19, especially for countries with low vaccination rates.