Everything we know about Pfizer’s ‘game-changing’ pill and the fight against Covid-19

Pfizer yesterday revealed results from a clinical trial that are extremely encouraging in relation to the ongoing fight against Covid-19.

The medication under examination was Paxlovid, an antiviral mix of two drugs given to people recently diagnosed with Covid-19.

The clinical trial found that when given to high-risk patients within three days of the onset of symptoms, it reduced the chance of hospitalisation and death by up to 89pc.

People were also 88pc less likely to be hospitalised or die if they received the drug within five days of the onset of symptoms.

What is Paxlovid?

The treatment is an antiviral that comes in tablet form (two different drugs taken together) and is produced by pharma giant Pfizer. Antivirals work by fighting off the virus, reducing the symptoms and shortening the length of illness.

The drug works by preventing the enzyme responsible for the replication of Covid-19 from doing so. Paxlovid has been found by Pfizer to greatly reduce the more severe effects of Covid-19 on those most at risk of being hospitalised or dying.

How do people take the drug and for how long?

Paxlovid is made up of two different pills; nirmatrelvir and ritonavir. Patients take two 150mg tablets of nirmatrelvir and one 100mg tablet of ritonavir twice every day for five days. The different pills will be packaged together in the same box.

Just how effective is Paxlovid?

The trial involving 2,246 high-risk adults with at least one underlying condition found it will reduce the viral load in a patient treated with the tablet by 90pc and will lessen their chances of ending up in hospital or dying by 89pc.

In the trial itself, 697 adults were given the drug within three days of first having symptoms and just five ended up in hospital after 28 days. None died.

This compared to 44 out of 682 people who received the placebo being hospitalised after 28 days, with nine deaths in this group.

Of the 1,038 people who received it within five days of symptoms, eight were hospitalised and none died. This compares to 66 hospitalisations in the 1,046 people who got the placebo and 12 subsequent deaths.

Pfizer has also said the drug will “retain robust antiviral activity against variants of concern”, such as Omicron.

If Paxlovid is deemed safe and approved by agencies such as the FDA in the US and the European Medicines Agency (EMA) in the EU, the drug could dramatically reduce the number of deaths from Covid-19 globally.

When might this approval occur?

This is not yet known but Pfizer is moving quickly and has already submitted the findings of its trial to the FDA in the US with a view to gaining emergency use approval.

A similar emergency-use approval was granted for another antiviral by the EMA recently and the EU agency is already examining the Pfizer trial results with a view to passing a ruling on emergency use in the coming week.

When would the drug be widely available?

As reported by the Irish Independent today, Pfizer Ireland officials told the Government yesterday that the company would probably be in a position to supply the treatment to Ireland as early as the end of January or in February, subject to regulatory approval.

The drug itself is being manufactured by Pfizer at its Irish plants in Ringaskiddy and Newbridge, as well as many other plants worldwide, in advance of its market authorisation. Considering the ramifications of such a drug being widely available, the EMA will likely approve the drug as quickly as is possible, albeit after rigorous testing.

Many countries such as Israel and the UK have entered into advance purchase agreements with Pfizer in relation to Paxlovid.

Are there any other drugs like this coming?

Yes, many of them. Merck/MSD and Ridgeback Therapeutics have already received emergency use approval for their antiviral molnupiravir from the EMA. The company recently downgraded expectations of reduced hospitalisations from 50pc to 30pc but was still granted emergency use in the US by the FDA.

Remdesivir is also in use in the US and many other companies such as Regeneron are producing monoclonal antibodies, which are given intravenously. These are currently expensive to purchase and not yet available to the general public.