LONDON – Britain said on Wednesday that it would limit the use of AstraZeneca’s vaccine in adults under 30 due to the risk of rare blood clots. This is a blow to the efforts of many countries that rely on the vaccine to stop the coronavirus pandemic amid a worldwide boom in cases.
The European Medicines Agency added the inconvenience, a “possible link” between the vaccine and rare blood clots, even though he said Covid-19 remained the much greater threat, and decisions on the use of the vaccine in hand of the 27 left. Member States of the European Union.
The decisions represent a significant setback for the AstraZeneca shot, which is seen as the main weapon in the fight to reduce deaths in the south starved by the vaccine.
It is the most widely administered coronavirus vaccine worldwide, it is much cheaper and easier to store than some of the alternatives, which encourages its use in at least 111 countries, rich and poor. AstraZeneca, based in Britain, has promised to deliver three billion doses this year, enough to vaccinate almost one in five people worldwide.
Britons under 30 will receive another vaccine if it is available, with limited exceptions, officials said. Until Wednesday, Britain had no doubts about the use of the vaccine brought home, while many European neighbors interrupted the injections due to the unusual but sometimes fatal blood clots.
But cases have also begun to appear in Britain, and since then a consensus has emerged among global regulators that the evidence points to a possible, as yet unexplained link between the vaccine and rare blood clots.
Amid a brutal wave of Covid-19 in Europe, security issues slowed vaccinations, lowered confidence in the shot and created a patchwork quilt of different policies across the continent. However, the most devastating effects of the security scare could still fall on poorer countries that are completely dependent on AstraZeneca’s vaccine.
The concerns arose even though the blood clots were extremely rare. According to Sunday, officials said European regulators had received reports of 169 blood clots in the brain and 53 other clotting events, often combined with low platelets, among about 34 million people who received the AstraZeneca vaccine across Europe.
Britain has bought enough vaccines from various manufacturers not to significantly slow down the policy change on AstraZeneca. But other countries are starving for doses. Cameroon and the Democratic Republic of Congo have already delayed injections of AstraZeneca’s vaccine amid growing concerns in Europe. Any further hesitation, according to scientists, could cost lives.
“In developing countries, the dynamic is to either use the vaccine or you have nothing,” said Penny Ward, a visiting professor of pharmaceutical medicine at King’s College London. “In which case does the massacre occur?”
The British and European regulators told the vast majority of people on Wednesday that the benefits of AstraZeneca’s shot outweigh the risks. The coagulation problems occurred at about one in every 100,000 recipients in Europe. Meanwhile, the vaccine in Britain has driven the hospitalizations of Covid-19 – which in itself could cause serious clotting problems – and saved thousands of lives, regulators said.
British health officials have estimated that the risk of being admitted to an intensive care unit for Covid-19 outweighs the dangers of the unusual blood clots in almost all age groups, and at almost every outbreak level.
But because younger people are less likely to develop severe Covid-19, regulators have said that any vaccine given in the age group should remove a higher safety bar. British data also suggest that younger people are more prone to the rare blood clots, which makes health officials there and in Europe more powerful to give them the vaccine.
In response to the new regulations for regulations, Italy on Wednesday recommended not giving the AstraZeneca shot to people under 60. A number of countries, including Germany, France, Canada and the Netherlands, have already stopped using it in younger people, with the age limit being set. at 55 or 60. Norway and Denmark brought the shot to a complete halt while investigating.
“The balance between benefits and risks is very favorable for older people, but it is more finely balanced for the younger people,” said Dr. June Raine, Britain’s chief regulator, said.
The blood clots caused increasing concern due to their unusual constellation of factors: blockages in large veins, often those that drain blood from the brain, coupled with a low platelet count.
The rise of the cases in early March has seen countries face the most important regulatory tests since shots were first fired. In the vaccination of millions of people, problems would inevitably arise that were too rare to appear in clinical trials with thousands.
But while scientists have called for coordinated action, health officials across Europe have defied the European Medicines Agency’s recommendations and suspended injections of the AstraZeneca vaccine. Most resumed the shots a few days later.
Some experts said the interruptions were understandable, but that the flip-flopping was disorienting, all the more so amid an ugly dispute between European lawmakers and AstraZeneca over drastic declines in supply that led some political leaders to inject falsely too malicious. Surveys have begun to show that in Germany, France and Spain, most people doubted the safety of the vaccine.
In general, the use of the shot suffered: across Europe, 64 percent of the doses of AstraZeneca’s vaccine were injected into people’s arms, which is significantly lower than the rates for other shots.
“One would have hoped there would have been cooperation and more discussion between regulators, instead of many different countries starting in all sorts of directions,” Professor Ward said. “The aspect was really the most unhelpful.”
As doctors in Europe examined the rare blood clots, they became more convinced of a connection, however poorly understood, with the vaccine.
The vaccine appears to cause an immune response targeting small platelets, doctors and regulators said. The platelets, in turn, caused dangerous blood clots in various parts of the body, including in the brain, which in some cases led to a rare type of stroke.
But the doctors said that is why some people have generated antibodies that generate platelet targets. Some component of the vaccine, or an excessive immune response in certain recipients – or both – may be the cause. No known conditions are known to make patients more vulnerable.
More women than men experienced the clotting problems, but British regulators said it was apparently the result of women being vaccinated in higher numbers due to medical roles in the front line.
Regulators have asked vaccines and doctors to look for certain symptoms, including severe and persistent headaches and small blood stains under the skin. Doctors’ groups have distributed guidelines on treating the disease.
On March 22, regulators reviewed 86 cases in detail, 18 of which were fatal, they said.
Concerns about the shot became enough in Britain this week that the University of Oxford, which developed the vaccine with AstraZeneca, stopped giving doses as part of a two-month-old study in children.
“Safety was our priority during the development of the vaccine,” said Andrew Pollard, the Oxford researcher responsible for the trials, on Wednesday. The identification of the blood clots, he added, “shows that the security system is working.”
In the United States, AstraZeneca is preparing to apply for emergency use with the Food and Drug Administration. If and when they accept the application, the agency’s regulators are expected to investigate the coagulation cases.
The United States, which is filled with vaccines from three other manufacturers, may not ultimately need AstraZeneca’s chance. But any FDA ruling is expected to carry significant weight in some of the poorer countries that rely on the shot.
The World Health Organization said a vaccine safety subcommittee met on Wednesday, noting that “rare side effects after vaccinations should be assessed on the basis of the risk of deaths due to Covid-19 disease and the potential of the vaccines. to prevent infections. ” It is said that a connection with the coagulation problems, although “credible”, has not been confirmed.
For Britain, the AstraZeneca vaccine has become a major source of national pride, and the backbone of the country’s rapid vaccination program.
Even if younger people are at lower risk due to severe Covid-19, scientists have said that its vaccination is essential to create enough protection in the population to end the pandemic.
Emma Bubola, Monika Pronczuk and Rebecca Robbins reported.