A drug which developers say works against the Omicron coronavirus variant has been approved by the UK’s medicine regulator.
The Xevudy (sotrovimab) treatment has been found to cut hospital admissions and death by 79 per cent in those deemed most vulnerable to the disease.
Omicron mutations did not elude drug activity in tests by the drug firm Vic, which has joined up with GlaxoSmithKline to produce the treatment. Tests are continuing to confirm the results against all of the Omicron mutations, the producers said. “Sotrovimab was deliberately designed with a mutating virus in mind," said Vir chief executive George Scangos.
A senior South African scientist, where Omicron was first identified to the World Health Organisation, said on Thursday that South Africa was reporting an increase in Covid-19 reinfection in patients contracting Omicron in a way that it did not experience with previous variants.
"Previous infection used to protect against Delta but now with Omicron that doesn't seem to be the case," Prof Anne von Gottberg said on Thursday at an online briefing organised by the World Health Organisation.
She said scientists believe symptoms are less severe for those reinfected or infected after vaccination.
"So we believe, I think very much so, that the reinfections [of the] ... disease will be less severe."
The UK government has ordered about 100,000 doses of Sotrovimab, which is administered intravenously over 30 minutes.
The Medicines and Healthcare products Regulatory Agency approved the drug for people with mild to moderate coronavirus who are at high risk of developing severe disease.
The treatment showed good efficacy in Phase 3 trials aimed at the Delta variant.
The co-developers of the therapy said data showed it "retains activity against mutations of the new Omicron Sars-CoV-2 variant".
Nine new cases of the Omicron strain were reported on Wednesday in England, bringing the UK total to 32.
"By targeting a highly conserved region of the spike protein that is less likely to mutate, we hoped to address both the current Sars-CoV-2 virus and future variants that we expected would be inevitable," Mr Scangos said.
"This hypothesis has borne out again and again, with its ongoing ability to maintain activity against all tested variants of concern and interest to date, including key mutations found in Omicron, as demonstrated by preclinical data.
"We have every expectation that this positive trend will continue and are working rapidly to confirm its activity against the full combination sequence of Omicron."
Australia in August became the first country to approve Sotrovimab, months before the Omicron variant was detected. The drug is the second monoclonal antibody treatment to be approved for use in the UK after Ronapreve, which was given to former US president Donald Trump when he had coronavirus last year.
The MHRA said the drug works by binding to the spike protein on the outside of the virus, preventing it from attaching to and entering human cells so it cannot replicate in the body.
The regulators said they were working with the manufacturers to establish effectiveness against Omicron.
"This is yet another therapeutic treatment that has been shown to be effective at protecting those most vulnerable to Covid-19 and signals another significant step forward in our fight against this devastating disease,” said Dr June Raine, MHRA chief executive.
Based on the clinical trial data, the drug is most effective when taken during the early stages of infection. As a result, the MHRA said it should be given as soon as possible and within five days of the onset of symptoms.
Sotrovimab is approved for people who have mild to moderate Covid-19 infection and at least one risk factor for developing severe illness. These include obesity, being 60 or over, diabetes or heart disease. It has not been approved for children under 12.
Moderna says it is working on booster vaccines aimed at tackling Omicron and expects them to be ready by March. The company's chief has issued a warning that the Omicron variant could evade the vaccines currently on the market.
Ministers are taking advice on whether children aged 5 to 11 should be given Covid-19 vaccines, the government said.
“The data at the moment suggests that young children are much less vulnerable but, as and when that data changes, we are guided by the science and we stand ready, which is partly why we have procured the vaccines – to make sure we can deliver what our citizens and patients need,” UK Science Minister George Freeman told Sky News.
He said it was an “urgent priority” to administer booster shots to the population over the coming weeks. Prime Minister Boris Johnson this week announced the extension of the booster vaccine campaign to cover all over-18s. He said every adult in England would be offered a third dose of a vaccine by the end of January.
Mr Freeman said the UK government had bought extra booster doses to cover the next two years because the public expects minister to “make sure our citizens are safe”.
Ministers revealed they have signed deals for 114 million Moderna and Pfizer-BioNTech shots, which are scheduled to be delivered in 2022 and 2023.
Asked why the UK was buying up more vaccines when developing countries still do not have enough to inoculate their populations, Mr Freeman said: “It is a balance. We’ve got another variant.”
Meanwhile, France’s leading scientific adviser said the Omicron variant could become the most common coronavirus strain in the country by the end of January.
On Thursday, Jean-Francois Delfraissy told BFM television the "true enemy" was still the Delta variant, which is spreading in a fifth wave across much of Europe.
"We should see a progressive rise of the Omicron variant, which will take over from Delta", possibly by the end of January, he said.
Separately, researchers believe they may have found a link between the Oxford/AstraZeneca shot and blood clots. Many countries suspended the use of the UK-made vaccine after people suffered from side effects.
A study by scientists in the UK and US found the interaction between the vaccine and a protein, known as platelet factor 4, could be behind the cases of thrombosis with thrombocytopenia syndrome.
Researchers believe this may spark a chain reaction in the immune system that can culminate in blood clots, a condition known as vaccine-induced immune thrombotic thrombocytopenia.