Covid vaccines slash risk of infection, illness and death, UK studies find

This appears the most comprehensive report of the encouraging data emerging on the effectiveness of vaccination roll-out in the “real world”. – Owl

Clive Cookson and Anna Gross in London yesterday 

Vaccination against coronavirus provides high levels of protection against Covid-19 infection, illness and death, according to three UK studies released on Monday that provide scientific support for the government’s road map out of lockdown.

The first, carried out in Scotland, found that the Covid-19 vaccination campaign led to a “very substantial” drop in serious illness across all adult age groups. It is the clearest evidence yet that single doses of coronavirus jabs can significantly reduce the risk of hospitalisation, even among the elderly.

Two other studies released by Public Health England echo findings released last week by scientists in Israel where vaccination has been even faster than in the UK. PHE scientists reported that the BioNTech/Pfizer vaccine reduced the risk of infection by more than 70 per cent three weeks after the first jab, rising to 85 per cent after the second dose.

Despite the promising news, the government also released studies by modellers at Imperial College London and Warwick university that indicated that another 30,000 people could die in the UK from Covid-19 before the end of June, based on the current vaccination rate and speed of lockdown easing.

The vaccination research in Scotland, which has not yet been peer-reviewed, is particularly relevant to assessments of the Oxford/AstraZeneca vaccine, which had less clinical trial evidence about efficacy in the elderly than some other vaccines. This had led some European countries to recommend against administering it to those over 65.

Chart showing that Scottish data shows a single dose of Covid-19 vaccines offers very strong protection against hospitalisation, including among the elderly

According to the research, conducted by the universities of Edinburgh and Strathclyde and Public Health Scotland, the chance of hospitalisation from four to six weeks after vaccination was 85 per cent lower after receiving one shot of the BioNTech/Pfizer vaccine and 94 per cent lower after one shot of the Oxford/AstraZeneca vaccine. 

The scientists said their findings were applicable to other countries using the two vaccines but the data were not robust enough to compare the two jabs’ efficacy head to head.

Chart showing that English data shows strong vaccine efficacy among healthcare workers aged under 65, including after a single dose

The second PHE analysis, based on routine testing data in people aged over 80, found that one dose was 57 per cent effective against symptomatic Covid-19 disease from about three to four weeks after the first dose. Early results suggested the second dose in over-80s improved protection against symptomatic disease to more than 85 per cent.

The two PHE studies only had enough reliable data to assess the BioNTech/Pfizer jab, which dominated the early stages of the UK vaccination programme, said Mary Ramsay, PHE head of immunisation. “But the Oxford/AstraZeneca vaccine data are also showing signs of a good effect,” she added.

Chart showing that English data shows BioNTech/Pfizer vaccine offers good protection against infection among over-80s, especially after a second dose

The Scottish study looked at the health records of 5.4m people in Scotland, equivalent to 99 per cent of the population. About 1.14m of those people were vaccinated between December 8 and February 15.

“These are national data strongly demonstrating that the vaccines are providing a very substantial reduction in hospital admissions from day seven onwards,” said Prof Aziz Sheikh, director of the University of Edinburgh’s Usher Institute. “Overall we’re very very confident this is making a difference.”

There is international interest in the impact of the vaccination campaign in the UK, which was the first large country to begin vaccinating its population against Covid-19 with approved inoculations. The UK also unusually opted to extend the interval between doses from four to up to 12 weeks, in order to vaccinate more people with a single dose more quickly.

Sir Mene Pangalos, AstraZeneca’s head of research and development, said he was “extremely encouraged” to see the first evidence of the effectiveness of the vaccine in the “real world”, referring to the Scottish research.

“Comparable vaccine effects were seen across all age groups,” he said. “This data provides further evidence that the vaccine protects against severe Covid-19 outcomes, particularly in older populations who are at the highest risk.”

The PHE study of healthcare workers, called Siren, included 40,000 people who were tested for coronavirus every two weeks, whether or not they had symptoms, between December 7 and February 5. “We are showing a really strong effect in reducing infection,” said Susan Hopkins, PHE’s Covid-19 response director.

Ramsay said: “The BioNTech/Pfizer vaccine is stopping people from getting infected, while also protecting cases against hospitalisation and death. We should be very encouraged by these initial findings.”

Professor Arne Akbar, president of the British Society for Immunology, who was not involved in the research, commented: “Overall these new findings should provide reassurance around the UK’s decision to offer the two doses of the vaccine 12 weeks apart.”

But he added: “It is still the case that the highest and longest lasting protection from getting ill with Covid-19 will only be provided by getting two doses of the vaccine.”

Sir Patrick Vallance, UK chief scientific adviser, welcomed the findings about vaccination but warned that the backdrop to lifting restrictions remained difficult. “We are not starting all this, as of today, from a good position. We’re not now in a ‘let’s release everything’ [situation], we’re in a not-very-good position that is getting better,” he told a media briefing. 

The central message that emerged from all the scientific modelling that fed into government decision-making was to “start from a low baseline to try to get numbers down before you start releasing”, Vallance said. “Go slowly, go in blocks you can measure the effect after four or five weeks,” he added. 

Many epidemiologists expect infections to increase again as restrictions are eased, with R, the average number of people infected by an individual with the virus, rising above 1, and then dropping after more people are vaccinated.

Additional reporting by Sarah Neville