- The European regulator this week declared the AstraZeneca-Oxford University vaccine safe.
- But it will keep investigating reports of rare clots after vaccination, particularly among younger women.
- These investigations into side effects shouldn’t worry us – they’re a sign monitoring is working.
- See more stories on Insider’s business page.
All effective medicines have side effects. We put up with them because, overall, the medicines make us feel better, or prevent something far worse.
The same principle applies to COVID-19 vaccines.
The benefits of AstraZeneca’s shot in preventing COVID-19 – which has killed 2.6 million people worldwide – outweighs the risk of any side effects, the European medicines regulator said Thursday. Its statement followed a thorough investigation into reports of rare and serious blood clots in vaccinated people.
The European Medicines Agency (EMA) said it found no increased risk of blood clots overall with AstraZeneca’s vaccine. But it couldn’t rule out a link between the vaccine and very rare, serious blood clots in the brain, or a clotting disorder called disseminated intravascular coagulation (DIC), particularly in women under 55 years old.
The EMA still recommended that people in this demographic take the shot because the risk of these blood disorders was “extremely small.”
Despite the recommendation, France announced Friday that it would not give people under 55 AstraZeneca’s vaccine.
Ian Douglas, professor of pharmacoepidemiology at the London School of Hygiene and Tropical Medicine, told Insider that the EMA’s announcement was not worrying, but “reassuring.”
It not only showed that potential side effects were being monitored closely, but that regulators were being upfront with the public, he said.
“For these reports to happen, there needs to be a suspicion of a link. But everytime we hear it, it won’t mean that it has been caused by the vaccine necessarily,” he said.
“It would be worse if all this was being done in secret, and something got out.”
Lots we still don’t know about the rare blood clots
There are lots of details that we don’t yet know about the 25 reported cases of serious clots: 18 in the brain, seven elsewhere in the body, related with DIC.
It’s possible that these people were at increased risk of blood clots anyway. For example, they may have had underlying illnesses linked to clots, including COVID-19, or an inherited blood disorder. Smoking, the combined oral contraceptive pill, and hormone replacement therapy are all common reasons a woman under 55 may have an increased blood-clot risk.
The EMA also said that a greater number of women under 55 may have been immunized with AstraZeneca’s vaccine, due to targeted vaccine campaigns in different EU countries.
The EMA has updated the AstraZeneca vaccine’s leaflet for patients and healthcare professionals to include signs and symptoms of clotting, so people know when to seek help. A severe or worsening headache or blurred vision after immunization requires prompt medical attention, for example, whereas a mild headache doesn’t.
Regulators may well establish more potential links between serious illness and other COVID-19 vaccines over the next few months, and issue more guidance. This shouldn’t cause alarm: it’s simply a sign that the monitoring system works.