BERLIN - Several German regions again suspended AstraZeneca shots on Tuesday for people under 60 after new reports of unusual blood clots, prompting Chancellor Angela Merkel to call an urgent meeting about the continued use of the coronavirus vaccine.
The news is the latest blow to the vaccine, which is critical to Europe’s immunization campaign and a linchpin in the global strategy to get shots to poorer countries. It comes less than two weeks after the EU drug regulator said the vaccine does not increase the overall incidence of blood clots following a similar scare. The European Medicines Agency said at the time that the benefits of vaccination outweigh the risk, but it could not rule out a link between the shot and some unusual kinds of clots and recommended adding a warning about possible rare side effects.
Authorities in Berlin, Munich, Brandenburg state and the country's biggest, North Rhine-Westphalia, made the decision to temporarily halt vaccinations for younger people after the country’s medical regulator said it had received additional reports of an unusual form of blood clot in the head, known as sinus vein thrombosis, in recent recipients of the AstraZeneca vaccine. All together, those areas are home to almost a third of the German population.
The Paul Ehrlich Institute said a total of 31 such blood clots were reported by March 29 out of some 2.7 million doses of AstraZeneca that have been administered across the whole of Germany so far. Nine of the people died and all but two of the cases involved women, who were aged 20 to 63, it said.
The suspensions come as Germany, along with other European countries, is scrambling to ramp up its vaccine program, which lags far behind those in Britain and the United States. By Monday, some 13.2 million people in the country had received at least one dose of vaccine, while 4.8 had received both shots.
Use of the AstraZeneca vaccine was temporarily halted in several European countries earlier this month over concerns about the rare blood clots. After a review by medical experts at the European Medicines Agency, most European Union countries, including Germany, resumed use of the vaccine on March 19.
On Monday, Canada suspended use of the AstraZeneca vaccine in people under 55, citing new concerning data from Europe.
"There is substantial uncertainty about the benefit of providing AstraZeneca COVID-19 vaccines to adults under 55 given the potential risks," said Dr. Shelley Deeks, vice chair of Canada's National Advisory Committee on Immunization.
Deeks said the updated recommendations come amid new data from Europe that suggests the risk of blood clots is now potentially as high as one in 100,000, much higher than the one in one million risk believed before.
Two state-owned hospitals in Berlin announced Tuesday that they had stopped giving the AstraZeneca vaccine to female staff members under 55. The heads of five university hospitals in western Germany called for a temporary halt to the vaccine for all younger women, citing the blood clot risk.
Berlin state's top health official, Dilek Kalayci, said the suspension of AstraZeneca vaccines for younger people was done as a precaution.
"We have not had a case of serious side effects in Berlin yet," she said, adding that all of those who had received the AstraZeneca shot already could rest assured that it provides good protection against the coronavirus.
"Still, we need to treat it carefully and wait for the talks taking place at the federal level," said Kalayci.
The decision could affect appointments for tens of thousands of teachers and people with preexisting conditions who received invitations to get vaccinated in Germany's capital in recent days. Appointments for the AstraZeneca shot were available sooner than ones for the vaccines made by Pfizer-BioNTech and Moderna.
German news agency dpa quoted a spokesman for Munich, the country's third-largest city, saying that the suspension of AstraZeneca vaccinations for people younger than 60 would last "until issue of possible vaccine complications for this group of persons has been resolved."
Scientists at the University of Greifswald, Germany, this week published the results of their investigation into the possible causes of the blood clots, saying the condition is similar to a side effect seen in some patients who receive the blood thinning medication heparin.
The study, which hasn't been peer-reviewed yet, doesn't provide a conclusive explanation for why some people vaccinated with the AstraZeneca shot develop the rare blood clots. Still, experts not involved in the study said it offers important information to doctors.
Alice Assinger, a specialist in vascular diseases and blood clot research at the Medical University of Vienna, said there is a treatment for the clots.
But Bernd Salzberger, an infection specialist at the University Hospital Regensburg in Germany, cautioned that the generally low risk of death from COVID-19 in younger women could be similar to the risk of suffering a serious blood clot.
"That's why the AstraZeneca vaccine should be primarily used in older people," he said.
Some other European countries remain hesitant about giving the AstraZeneca shot to older people, however. In Madrid, residents ages 60 to 65 started receiving the vaccine Tuesday ahead of those between the ages of 66 and 79 because Spanish authorities have not yet reviewed new data provided by AstraZeneca about how well it works in the older age group.
Spain is currently using the Pfizer-BioNTech and Moderna vaccines for people over 80 years old.
Spanish health authorities have said that they are hoping to speed up the rollout of vaccines with the arrival of the jab developed by the pharmaceutical company Janssen, a subsidiary of Johnson & Johnson, which has also been approved for use in Europe and requires one shot only.