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The United Kingdom defended its decision to postpone the second dose of vaccines as the best way to fight the coronavirus, while more countries adopt a similar strategy in a race against the increase in cases and new strains.
UK Health Secretary Matt Hancock said on Sunday that there is great confidence that the first dose provides “decent effectiveness” against the virus and that the country’s plan will speed up vaccinations across the country.
“You want as many people as possible to have as much protection as possible, as quickly as possible,” Hancock said in an interview with Sky News. “This is the way to save most lives more quickly.”
Governments around the world are fighting to review vaccination programs, as research shows that strains from the UK, South Africa and Brazil are more contagious or possibly even more lethal than the original virus. And countries are increasing restrictions on international travel, as scientists assess whether existing vaccines are as effective against variants.
Supply problems are also hampering the release of vaccines, increasing pressure to give as many people as possible the first injections, rather than withholding doses to complete the two-course regimen earlier. Both AstraZeneca Plc. And Pfizer Inc. said it will not be able to meet delivery targets for Europe in the coming weeks, increasing the pressure to stretch existing supplies. The states of the United States also had to slow down their vaccines due to difficulties in obtaining doses.
France on Saturday recommended doubling the time to six weeks between the first and second injections, concluding that this would lead to at least 700,000 more people being vaccinated in the first month.
Why mutated coronavirus variants are so worrying: QuickTake
Switching to longer dosage intervals can double the number of people who gain some protection from the virus in the short term, but it carries risks. It is unclear how much benefit a single injection of currently available vaccines will offer, and there is a danger that mutations may flourish if immunity decreases after the first dose.
French Orientation
The new French advice is for the vaccine made by Pfizer and BioNTech SE, as well as one provided by Moderna Inc .. Pfizer recommends that people receive their second dose in three weeks, while Moderna recommends a second dose in four weeks.
France’s move came after January 21 US Centers for Disease Control and Prevention statement that follow-up doses of Covid-19 vaccines could be administered up until six weeks later, if it is not feasible to obtain them within the recommended interval. The Food and Drug Administration also offered some flexibility for “modest delays”.
Research from Israel, which is a world leader in vaccination, shows that two days after a second injection, new infections and hospitalizations fell by about 60% from the peak. In an encouraging sign for the second dose to be postponed, however, trends began to change around two weeks since the first injection.
The UK has already extended the maximum waiting time from three to 12 weeks, as the Boris Johnson government plans to vaccinate 15 million people by mid-February. The UK is also vaccinating with the injection developed by AstraZeneca, which was more effective when administered with a up until 12 weeks.
The UK has administered more than 6 million doses, most in Europe, and Johnson tweeted on Saturday that each injection brings the UK closer to beating the virus. In France, just over 1 million people have been vaccinated.
Delays in dosing regimens are facing new questions from doctors, with the British Medical Association asking the UK to “urgently review” its decision allowing the second dose of the Pfizer-BioNTech vaccine to be postponed.
BMA said in a statement that it supported delays in up until 42 days, or six weeks, citing international guidance from the World Health Organization that this could work, but he warned that Britain’s plan goes “far beyond” that.
WHO Guidance
“BMA members are also concerned that, due to the unpredictability of supplies, there may be no guarantee that second doses of the Pfizer vaccine will be available in 12 weeks,” the group said in a statement.
The WHO said there is no data to support the UK decision, but said that changes in dosing regimens could be justified in emergency situations.
In its recommendation, the US CDC said, there is “limited data on the effectiveness” of the Pfizer and Moderna vaccines beyond the six-week interval, according to the guidance, but if the second dose is administered later, “there is no need restart the series. ”
(Updates with the study of Israel in the 10th paragraph)