New data from a study at Oxford University provides the first evidence that the COVID-19 vaccine developed by the prestigious school together with AstraZeneca can not only prevent disease with coronavirus, but could help substantially reduce its spread in the community. For the first time in a large-scale human study, all study participants in the UK were examined at regular intervals for COVID-19 infection after receiving a first vaccination, rather than participants who developed suspected symptoms of the disease. .
Oxford research, published online Tuesday as a “pre-printed” study by The Lancet, still being evaluated by colleagues, found that up to 12 weeks after the first dose of vaccine, there was a 67% reduction in positive tests. among study participants compared with those given a placebo.
A number of vaccines, including Oxford / AstraZeneca, Pfizer and Modern the formulas being widely used in the US and others have developed around the world have shown strong efficacy in preventing symptomatic infection, but there has been no evidence so far that any of these would prevent people carrying the disease without external symptoms.
Those asymptomatic carriers have been for a long time considered a major risk to transmit the disease to others, fueling its spread among populations.
For this reason, the latest data from Oxford has been greeted with great enthusiasm by British leaders, who have tied the hopes of their mass vaccination program largely to the Oxford / AstraZeneca vaccine. Nearly 10 million people had received a first dose of COVID-19 vaccine in the UK since Wednesday, many of them being shot with Oxford.
Prime Minister Boris Johnson hailed the results as “truly encouraging” and expressed his gratitude to the British scientists and national health workers who fueled the UK vaccination program, which was among the first to start. to operate in the western world.
UK Health Minister Matt Hancock also spoke of the “absolutely superb” data from Oxford, telling the BBC on Wednesday that the potential to reduce the silent spread of COVID-19 means the vaccine “will help us all get out from this pandemic ”.
The 12-week dosing delay was stated
In addition to evidence of asymptomatic infection prevention, data released by Oxford scientists on Tuesday reinforced the policy adopted by both Britons. and the European Union Drug regulators leave a gap of up to 12 weeks between the two doses of the Oxford / AstraZeneca vaccine.
The decision raised eyebrows when the UK regulator announced it just before Christmas, despite the Oxford-recommended range, as data available at the time did not clearly show that the vaccine would remain effective in the gap between photos.
But the pre-print study released on Tuesday showed that the first shot of the vaccine not only remained extremely effective (72% from 22 days to 90 days after the first dose), but actually left at least three months. between photos. increases the overall effectiveness to 82.4%.
In contrast, in students who received the second dose of the Oxford vaccine after six weeks, the effectiveness of the drug was only about 55%.
The US Food and Drug Administration has not yet granted emergency authorization for the use of the Oxford / AstraZeneca vaccine. In Phase 3, human studies are still ongoing in the US, as well as in the UK, Brazil and South Africa.
So far, the FDA has shown no inclination to support the longer-term strategy adopted by the UK and Europe if and when it approves the Oxford vaccine, but the latest UK data could influence US regulators.
The head of the Oxford vaccine group, Professor Andrew Pollard, who is also the lead scientist in the UK study on the drug, said the data was evidence that the 12-week dose interval was “the optimal approach to launch and ensure assuring us that people are protected after 22 days after a single dose. “
CBS News producer Steve Berriman contributed to the report.