An oral antiviral pill for Covid speeds up recovery among vaccinated yet vulnerable patients, but does not reduce their likelihood of needing hospital care or dying, research has suggested.
The UK became the first country in the world in November 2021 to approve molnupiravir for Covid, with the pill – which can be taken twice a day at home – given to patients through the Panoramic (Platform Adaptive trial of NOvel antiviRals for eArly treatMent of Covid-19 In the Community) trial.
At the time hopes were high after a study suggested that the antiviral halved the risk of hospitalisation or death among unvaccinated high-risk patients. But shortly after approval was given, further work, conducted when the Delta variant dominated, suggested the drug had a smaller effect than first thought.
Now research published in the Lancet has found molnupiravir does not reduce the risk of hospitalisation or death in vaccinated, high-risk people faced with the Omicron variant.
Prof Chris Butler, of the University of Oxford and co-chief investigator of the trial, said there might still be circumstances in which the antiviral might be helpful – for example, in helping key workers get back to work quicker if systems are under high pressure.
But, he added: “That’s a complex political decision which needs to be made, given the circumstances at the time.”
Adults in the UK were eligible for the trial if they tested positive for Covid either by PCR or lateral flow test, were sick in the community and were either aged 50 or above or over the age of 18 with a health condition that made them vulnerable to Covid.
Between 8 December 2021 and 27 April 2022 the team recruited more than 25,700 eligible participants, 94% of whom had received at least three doses of a Covid vaccine.
Half of the participants were randomly allocated to receive usual care, while half were couriered a five-day course of molnupiravir.
The results, based on a 28-day follow-up period, reveal that both groups experienced a similar rate of hospitalisations or deaths, with such outcomes recorded for 98 of the 12,525 participants who received usual care and for whom such data was available compared with 105 of 12,529 participants who were also given molnupiravir.
The team said the low rates highlight the importance of Covid jabs. “Vaccination is a very powerful tool for combating this pandemic,” said Butler.
However, participants given molnupiravir reported a median recovery time of nine days compared with 15 days for those only receiving usual care, with further analysis suggesting molnupiravir sped up recovery by 4.2 days on average.
Those given molnupiravir also had less contact with their GPs, and a higher rate of early, sustained recovery while fewer people in this group had virus detected after seven days, and their viral loads were lower.
Prof Martin Landray, also of the University of Oxford, but who was not involved in the trial, noted participants were aware if they were taking the antiviral.
“Whilst this knowledge wouldn’t influence the hospital admission or death we have no way of knowing if or to what extent it might bias the findings on self-reported symptomatic outcomes,” he said.
The cost-effectiveness of molnupiravir and any impact on long Covid has yet to be analysed.
However, Prof Richard Hobbs of the University of Oxford and the Panoramic co-trial lead, said a course of the antiviral is thought to cost several hundred pounds.
“So its deployment is going to depend on factors like how much a mean four-day improvement in symptoms is likely to benefit the country,” he said.