How effective is Paxlovid for COVID-19?

• Paxlovid lowers the risk of hospitalization or death from COVID-19 by 86% for adult patients who are at high risk of COVID-19 progressing to severe illness when Paxlovid is started within the first 3 days of COVID-19 symptoms. These results were from the study EPIC-HR (NCT04960202), which was a Phase 2/3, randomized, double-blind, placebo-controlled trial in non-hospitalized symptomatic adult subjects with a laboratory-confirmed diagnosis of SARS-CoV-2 infection.
• Paxlovid contains two co-packaged medicines: nirmatrelvir (previously known as PF-07321332) and ritonavir.
• Paxlovid contains oral tablets that are best taken at the first sign of symptoms of COVID-19.
• Paxlovid is taken to help decrease the number and severity of symptoms or avoid severe illness, which may lead to hospitalization or death.

Is Paxlovid FDA approved?

• Yes, Paxlovid is an FDA-approved medication.
• Paxlovid received FDA approval on May 25, 2023, for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death.
• Paxlovid is available under an Emergency Use Authorisation (EUA) to treat patients 12 to 18 years old for mild-to-moderate COVID-19 who are at high risk for progression to severe COVID-19, including hospitalization or death.
• PAXLOVID is not approved for use as pre-exposure or post-exposure prophylaxis for prevention of COVID-19.

How does Paxlovid work?

• Paxlovid contains co-packaged nirmatrelvir tablets and ritonavir tablets that are taken orally at the first sign of COVID-19 illness after a positive Sars-CoV-2 viral test.
• Nirmatrelvir works by blocking an enzyme (called SARS-CoV-2-3CL protease) that the coronavirus needs to replicate.
• As the virus can not reproduce itself, this reduces the severity of symptoms and so decreases the number of hospitalizations and deaths in high-risk patients.
• Ritonavir is an HIV medication that slows the metabolism of nirmatrelvir, which helps nirmatrelvir stay in the body longer and at a higher concentration, making it more effective.

How do you take Paxlovid?

Paxlovid is prescribed as a medicine to be taken at home for high-risk patients to avoid severe COVID-19 illness, including hospitalization and death. Paxlovid will be one box containing a full five-day treatment course with oral nirmatrelvir tablets and ritonavir tablets.

• Paxlovid should be started as soon as possible after a positive Sars-CoV-2 viral test and within 5 days of the first symptoms.
• Nirmatrelvir 300mg (two 150mg tablets) taken twice daily for five days.
• Ritonavir 100mg taken twice daily for five days.

Clinical Trials for Paxlovid.

Patients at HIGH RISK of hospitalization with COVID-19

Paxlovid is FDA-approved for treating mild to moderate COVID-19 in adult patients at high risk of severe COVID-19.

Final results from Phase 2/3 ERIC-HR study of the antiviral pill Paxlovid show it successfully decreases the risk of being hospitalized by 89% for patients at high risk of COVID-19 progressing to severe illness. Paxlovid or placebo was taken within 3 days of the first COVID-19 symptoms, and the results were:

• 0.7% (5 out of 697) of the Paxlovid patients were hospitalized with no deaths.
• 6.5% (44 out of 682) of the placebo patients were hospitalized with 9 deaths.
• Paxlovid patients also had a 10-fold decrease in viral load compared to the placebo group.

Patients at STANDARD RISK of hospitalization with COVID-19

Paxlovid is NOT authorized for COVID-19 patients who have the standard risk of hospitalization with COVID-19

Early results from a trial (Phase 2/3 EPIC-SR) looking at Paxlovid use in Covid-19 patients at standard risk of hospitalization showed a 70% reduction in hospitalization in the Paxlovid patients compared to placebo.

• 0.7% (3 out of 428) of the Paxlovid patients were hospitalized with no deaths.
• 2.4% (10 out of 426) of the placebo patients were hospitalized with no deaths.
• Paxlovid patients also had a 10-fold decrease in viral load compared to the placebo group, which was the same as the Phase 2/3 ERIC-HR study.

Related questions

• Paxlovid side effects: 8 key things to know
• How fast does Paxlovid work?
• Can you take Paxlovid twice if COVID rebounds?

Can Paxlovid prevent COVID-19?

Post-Exposure Prophylaxis of COVID-19 using Paxlovid

Paxlovid is not authorized to be used to prevent COVID-19.

The study, Phase 2/3 EPIC-PEP, looked at how well Paxlovid worked in adults at preventing COVID-19 after being exposed to the virus through household contact. The percentage of adults who developed COVID-19 was lower in the Paxlovid-treated groups compared to the placebo group, but it was not statistically significant.

The percentage of subjects who had developed COVID-19 up to Day 14 was 2.6% for the 5-day Paxlovid group and 2.4% for the 10-day Paxlovid group, compared to 3.9% for placebo; however, these results were not statistically significant.

Click here for more information on: Paxlovid: Uses, Doses, Side Effects and Interactions.

Bottom Line:

• Paxlovid is effective at lowering the risk of hospitalization or death by 86% for adult patients who are at high risk of COVID-19 progressing to severe illness when Paxlovid is started within the first 3 days of COVID-19 symptoms.
• Paxlovid received FDA approval on May 25, 2023, for the treatment of mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who are at high risk for progression to severe COVID-19, including hospitalization or death.
• Paxlovid is available under an Emergency Use Authorisation (EUA) to treat patients 12 to 18 years old for mild-to-moderate COVID-19 who are at high risk for progression to severe COVID-19, including hospitalization or death.