The Oxford-AstraZeneca vaccine can reduce coronavirus transmission by up to two-thirds, a study suggested, marking the first time that an injection has shown this effect.
The Oxford University study published on Tuesday, which is awaiting peer review, found that those who were vaccinated with a single dose of the vaccine were 67 percent less likely to test positive with a CRP test.
The article suggests that the vaccine, which was developed by the University of Oxford in partnership with the Swedish-British pharmaceutical giant AstraZeneca, may have a “substantial effect on the transmission of the virus” as a result and also prevent serious illnesses.
Health Secretary Matt Hancock said the study, which also suggests that the Oxford-AstraZeneca injection is highly protective after a single dose, showed that “vaccines are the way out of this pandemic”.
“This news about the Oxford vaccine is absolutely excellent,” tweeted Hancock. “This vaccine works and works well.”
This news about the Oxford vaccine is absolutely excellent.
📉 2/3 reduction in transmission
💉 Stronger 12-week interval protection between doses
🏥 No hospitalizationsThis vaccine works and works well 🇬🇧
https://t.co/B1WPLf6dJB– Matt Hancock (@MattHancock) February 2, 2021
Oxford scholars approve 12-week dosing interval
The study also showed that the vaccine was 76% effective against symptomatic infections for three months after a single dose, a level that would increase if the second injection was postponed.
Test results in Britain, Brazil and South Africa showed that immune responses were boosted with a longer interval between the two doses, among participants aged between 18 and 55 years.
“The effectiveness of the vaccine after a single standard dose of vaccine from day 22 to day 90 post-vaccination was 76 percent, and the modeled analysis indicated that protection did not decrease during this initial 3-month period,” said academics from Oxford.
The study added that the vaccine’s effectiveness was 82.4 percent with 12 or more weeks for the second dose, compared with 54.9 percent for those where the booster was given less than six weeks after the first dose.
The findings supported the UK’s decision to extend the interval between starting doses and boosting injections to 12 weeks, Oxford academics said.
The UK decided to vaccinate as many people as possible, as quickly as possible, increasing the time between initial vaccines and booster doses.
Andrew Pollard, chief investigator for the Oxford Vaccine Trial, said the data shows that the 12-week interval is “the ideal approach to be implemented and ensures that people are protected 22 days after a single dose”.
The head of research at AstraZeneca said that eight to 12 weeks between doses appeared to be the “sweet spot” for effectiveness, in contrast to Pfizer, which warned that its vaccine – developed with BioNTech in Germany, was not tested with this interval. .
Questions about the elderly
The study did not address the growing questions about the lack of data on effectiveness among the elderly, a group that the UK government has given the highest priority in vaccine implantation.
The longest interval between doses for those 56 and older was between six and eight weeks, so there was no data on the effectiveness of a 12-week dosing interval in this cohort.
The study said that none of the 12,408 people vaccinated with a single dose of the vaccine were hospitalized with COVID-19, starting 22 days after immunization.
Europe’s drug regulator recommended the Oxford-AstraZeneca vaccine for adults of all ages, but also signaled that there is insufficient data to determine how it will work in people over 55.
On Tuesday, Poland and Sweden joined countries that decided not to use AstraZeneca in the elderly.
The UK has expressed confidence that the vaccine works in all age groups and is ahead of other EU countries in the pace of implantation, having approved vaccines earlier.
Pollard of the University of Oxford said on Wednesday that the team’s researchers also believe that the vaccine will continue to offer protection against new variants of COVID-19, although data are still awaiting.
Even if the virus adapts, “it does not mean that we will not have protection against serious diseases,” he said.
“If we need to update the vaccines, then it really is a relatively simple process that takes just a matter of months, instead of the huge efforts that everyone made last year to get the large-scale tests to run,” Pollard told the BBC.