For young women, the risk of a blood clot after taking the Oxford/AstraZeneca coronavirus vaccine is extremely low — but that doesn’t mean they’re all confident.
“I would still take it,” said Sarah Gallagher, a 31-year-old from Brussels. “But I would be quite nervous about it.”
British and European regulators earlier this month announced an extremely rare link between the vaccine and blood clotting disorders. Women under 60 make up the majority of the blood-clot cases reported in Europe so far, but regulators in both Amsterdam and London found no reason to believe that women were more likely than men to suffer from the extremely rare side effect, or that age was a determining factor.
“Most of the cases occurred in individuals below 60 years of age and in women, but because of the different ways the vaccine is being used in the different countries, the committee did not conclude that age and gender were clear risk factors for these very rare side effects,” said Sabine Straus, who chairs the European Medicines Agency’s safety committee. The leading theory for what causes them is an immune response against the virus.
However, many EU countries flip-flopped on their recommendations following the announcement: whereas they first used the vaccine only in younger people, many are now limiting it to older people. The U.K., the Netherlands, Belgium and Spain are among those that have stopped giving the jab to certain younger age groups. Denmark stopped using the vaccine entirely. Meanwhile, Malta and Bulgaria continue to use the vaccine in all adults.
Young women interviewed for this article said these decisions had left them with more questions: Is a 31-year-old less at risk than someone who’s 30? Why is the vaccine used in someone age 60 in one country, but not just across the border? Should women be concerned if they’re taking birth control pills? Can they just get another vaccine?
Astrid van Hylckama Vlieg, an assistant professor who specializes in venous thrombosis at the Leiden University Medical Center, said it’s counterproductive for countries to suspend the vaccine: “That scares people without being sure that it really is such a risk that it starts to outweigh the benefits of the vaccine, which, it turns out, is not the case.”
Although there are no European-wide data analyzing skepticism based on gender and age, a Forsa poll conducted in Germany at the end of March found that men were significantly more likely to accept the Oxford/AstraZeneca shot compared to women, 60 percent versus 43 percent.
The EMA once again reaffirmed that the benefits of using the Oxford/AstraZeneca vaccine in all adults outweighed any risk, after a push from the Commission to harmonize guidance across the bloc, but did acknowledge that the benefits of the vaccine increase as age increases and rates of infection are high. With some reports of older people skipping their vaccine appointments, it remains to be seen whether younger women will show up when it’s their turn.
Personal decisions
Dominique Roch, a 34-year-old woman from Berlin, said her father canceled his appointment last month when he realized he would be offered the Oxford/AstraZeneca vaccine. His decision followed weeks of concern from German regulators over its efficacy in older people.
Then, at the end of March, she turned on German radio and heard a virologist say the vaccine wouldn’t be used in younger people: “I was like, ‘What? That’s not what you said before,” Roch said.
Roch said she would also probably turn the Oxford/AstraZeneca vaccine down if it were offered to her, citing a family history of thrombosis. Her father has had two pulmonary embolisms, while her grandmother lost a toe after blood clots in her legs.
It’s a textbook example of people across Europe attempting to conduct their own risk-benefit analyses. Even though the risk remains incredibly small, some women say they want to wait until regulators are certain about who’s at-risk before they roll up their arm for the vaccine. Others are asking to be offered another jab for peace of mind.
“The messaging on this has been very confusing, which is extremely unfortunate given the potential that it has to delay the vaccination rollout,” Gallagher said. “I would like further information about the risks and whether the EU is in a position to offer a replacement vaccine for those most at risk in the near future.”
For other women, taking the vaccine is a no-brainer: “The whole AstraZeneca ‘scandal’ around thrombosis got me rolling my eyes, as we know the risk[s] are much higher with female contraceptive[s],” Clara Weakley, a 22-year-old based in Paris, wrote in a message.
Yana Vinogradova, a senior research fellow at the University of Nottingham’s Department of Primary Care, studies the risk of blood clots from contraceptive pills and herself has had the Oxford/AstraZeneca vaccine. So has her 38-year-old daughter.
Anyone with concerns should talk to their doctor, she said. But it’s everyone’s responsibility “to contribute to stopping epidemics,” she added.
Relative risks
Regulators have tried to assuage concerns by comparing the Oxford/AstraZeneca vaccine to the contraceptive pill, which also carries a much higher — albeit small — the risk of blood clots. “It’s a necessity for many people in the same sort of way that a vaccine is,” Adam Finn, a professor of pediatrics at the University of Bristol, said of the pill in a briefing to reporters.
The risk of a blood clot after having the vaccine is somewhere between one in 100,000 and one in 250,000, or between 0.001 percent and 0.0004 percent, according to European and British regulators. The risk of a blood clot while taking the pill is around 0.04 percent per year, depending on a woman’s age and which medicine they are taking. Another fact to note, Van Hylckama Vlieg pointed out, is that these blood clots are often pulmonary embolisms or deep vein thrombosis — different than the clots found after the vaccine.
Regulators think the fact that women make up the majority of blood clotting cases may have more to do with who is being vaccinated. Higher numbers of women than men have had the shot, largely because they hold a greater proportion of health and care jobs. There also might be more cases in younger people because, in numerous EU countries, the Oxford/AstraZeneca vaccine had been limited to younger people.
But several women said that while they understand they may not be at higher risk, they don’t want to be the unlucky one.
Alison, a woman in her 40s living in Los Angeles who didn’t want to have her full name published, had cerebral venous thrombosis (CVT) 10 years ago: “Birth control was the single contributing factor,” she said. The news linking the vaccine to blood clots brought back painful memories for her.
“As a survivor of a CVT, the translation of [regulators’] explanation … is simple: There hasn’t been time to gather the data, and even if they could, they likely can’t say with 100 percent certainty that one leads to the other,” she said. “With me, it was the same — they cite birth control as the contributing factor but couldn’t use the term 100 percent sure.”
Alison doesn’t advocate against women taking the contraceptive pill, and she views the decision to take the Oxford/AstraZeneca vaccine as helping “the greater good.”
“[Regulators are] right,” she said. “It just badly hurts that the adverse clots in people like me are thrown to the side like we don’t matter.”
But she put her fears aside and received the Johnson & Johnson coronavirus vaccine, which is based on a similar type of technology and is also under close scrutiny for potential side effects.
