What is Paxlovid? Everything you need to know about Joe Biden’s antiviral Covid drug treatment

Late-stage clinical trial found nearly 90 per cent effectiveness from antiviral pill

In a letter to the White House press secretary on Thursday morning, presidential physician Kevin C. O’Connor confirmed that US President Joe Biden had tested positive for Covid-19.

The 79-year-old is currently resting and according to Dr O’Connor, is experiencing symptoms including a runny nose and fatigue which began Wednesday evening.

Dr O’Connor said in the letter to press secretary Karine Jean-Pierre that he anticipated Mr Biden would “respond favourably to treatment” in the form of Paxlovid.

Here’s everything you need to know about the antiviral pill:

What is it?

Paxlovid is an antiviral pill developed and produced by pharmaceutical giant Pfizer, which is taken orally and designed to limit severe illness from Covid-19.

The drug was approved for use in the United States in December last year by the Centers for Disease Control & Prevention (CDC) for people experiencing mild-to-moderate Covid symptoms.

Studies show that it can reduce the risk of hospitalisation and death in the most vulnerable Covid patients by nearly 90 per cent, according to Yale.

Hoe does it work?

The pill works by preventing Covid-19 proteins from multiplying inside the body during first five days of infection, allowing the immune system to fight the virus.

Paxlovid has two active ingredients, PF-07321332 – the antiviral medication itself – and ritonavir, which slows the other ingredient’s breakdown.

As The Independent reported last year, ritonavir has previously been used in HIV medicines to “boost” the effectiveness of the medication.

Who can take it?

People who are highly vulnerable to hospitalisation and death from Covid can access Paxlovid in the US, the CDC says.

High risk groups include the 65 and above, or those who have underlying conditions such as cancer, diabetes, obesity, or others. People with kidney disease may be prescribed a lower dose however.

Patients must weigh 88lbs or above and be at least 12 years old to be prescribed Paxlovid.

According to Yale, some people can access Paxlovid through their health care provider after testing positive for Covid-19. Ohers should be able to get the medication directly from a state-licensed pharmacist with some restrictions.

How do you take it?

Paxlovid consists of two tablets, nirmatrelvir and ritonavir tablets, which are taken together two times a day for a total of five days.

Nirmatrelvir is an oval, pink tablet and ritonavir is a white or off-white tablet, according to the CDC.

What do experts say?

A late-stage clinical trial found Paxlovid to reduce the risk of hospitalisation or death by 89 per cent. Those figures were submitted to the US Food and Drug Administration (FDA) last year prior to emergency approval of the drug.

At almost 90 per cent effectiveness, Paxlovid is nearly 60 per cent more effective than its closest rival – Merck’s Lagevrio – which, according to the Financial Times, can reduce the risk of severe illness or death from Covid by about 30 per cent.

Those involved in Pfizer’s clinical trial for Paxlovid began taking the drug in the first three days of symptoms or testing positive for Covid, while the CDC recommends patients do so before the fifth day.

Studies are ongoing.