Pfizer's Covid vaccine is 85% effective after one dose, study finds
0that bolsters Britain's decision to delay the second injection. The UK drew criticism in January when it pushed back the second dose from three weeks to three months because the jabs were never trialled using that dosing regimen. But the latest research on 9,000 healthcare workers, published in The Lancet, found that a single shot reduced the number of people developing symptomatic Covid by 85 per cent after three weeks. The study by the Sheba Medical Centre, one of Israel's top research hospitals, reported a 75 per cent drop in the number of people testing positive for the infection, suggesting the single shot will have a significant impact on blocking asymptomatic infection and transmission.A positive PCR swab would signal that even someone who is vaccinated is carrying fragments of the virus in their nose or throat which they could pass on. Reducing Covid's spread is critical for country's to achieve 'herd immunity', when so many people are immune that a disease peters out. Lead researcher Professor Arnon Afek, deputy director-general at Sheba, said: 'This groundbreaking research supports the British government's decision to begin inoculating its citizens with a single dose of the vaccine.' The UK has also been spacing out Oxford University's vaccine doses in a bid to get better coverage quicker, with the nation in a race against time to vaccinate as many vulnerable Britons as possible before the end of March.An Oxford study earlier this month found a single shot of that jab was 76 per cent effective for 12 weeks at stopping symptomatic disease and blocks seven in 10 people from spreading it. Share this article Share 613 shares Sheba epidemiologist Gili Regev-Yochay cautioned that the cohort studied at the hospital were 'mostly young and healthy'. Unlike with Pfizer's clinical trial, 'we don't have many (staff) here aged over 65,' she told reporters. But she also noted that the Sheba study took place during a surge in Covid-19 infections in Israel, which flooded hospitals with new cases.Pfizer declined to comment on the data, saying in a statement it was doing its own analysis of 'the vaccine´s real-world effectiveness in several locations worldwide, including Israel'.It hopes to use Israeli data to look at the potential of the vaccine to protect against Covid-19 arising from emerging variants, the drugmaker said.Pfizer's original trial of the vaccine found efficacy was 95 per cent if two doses were given 21 days apart. Other countries including Israel and the US are trying to stick more closely to the three-week gap proven in the clinical trial.It comes after England's Covid vaccine postcode lottery was laid bare last night.It emerged parts of London have jabbed just 60 per cent of over-70s - while almost every elderly person has had their first dose in one district in Hampshire.The NHS England statistics, which go up to February 14, also show that some parts of the country have dished out nearly 300 times as many second doses as ot