The World Health Organization (WHO) has endorsed the use of Pfizer’s oral Covid-19 antiviral Paxlovid (nirmatrelvir and ritonavir) in patients who are at elevated risk of hospitalisation.

Paxlovid is being recommended for Covid-19 patients who are at high risk of developing severe disease, such as unvaccinated, older, or immunosuppressed patients.

The recommendation is supported by positive data from two randomised controlled trials (RCTs) of Paxlovid in 3078 participants.

In the data, treatment using Pfizer’s oral Covid-19 antiviral reduced the risk of hospitalisation by 85%, in a high-risk patient population.

Pfizer designed the oral antiviral drug, a combination of nirmatrelvir and ritonavir, to inhibit the SARS-CoV-2-3CL protease, an enzyme essential for viral replication.

Paxlovid is recommended for administration soon after diagnosis of Covid-19 and within five days from the start of symptoms.

In November last year, Pfizer signed an agreement with the Medicines Patent Pool (MPP), an UN-backed public health organisation, to licence Paxlovid.

The United Nations (UN) agency said that Paxlovid is the most potent therapeutic choice for the treatment of high-risk patients to date.

However, availability, lack of price transparency in bilateral deals, and the need for accurate testing prior to administration limit the access to Paxlovid for low- and middle-income countries, said WHO.

WHO stated that it is extremely concerned that low- and middle-income countries will face challenges related to access to the treatment, as happened with Covid-19 vaccines.

Furthermore, the agency assured that Paxlovid will be included in its ‘WHO prequalification list’ with immediate effect, and complained that no generic products are available yet.

WHO in its statement, said: “One obstacle for low- and middle-income countries is that the medicine can only be administered while the disease is at its early stages; prompt and accurate testing is, therefore, essential for a successful outcome with this therapy.

“Data collected by FIND show that the average daily testing rate in low-income countries is as low as one-eightieth the rate in high-income countries. Improving access to early testing and diagnosis in primary health care settings will be key for the global rollout of this treatment.”

In addition to recommending the use of Paxlovid, WHO has also updated its recommendation on remdesivir, another antiviral medicine developed by Gilead Sciences.

Previously, WHO had restricted the use of remdesivir in Covid-19 patients regardless of their disease severity, based on the then-available evidence showing no effect on mortality.

With the publication of new clinical trial data, the agency has updated its recommendation and suggests its use in Covid-19 patients who are at high risk of hospitalisation.