EU agency says people should get 2nd dose of AstraZeneca too

Maria Cheng
Associated Press

London – The European Medicines Agency said Friday that people who have received a first dose of AstraZeneca’s COVID-19 vaccine should also get the second one despite the rare risk of blood clots that have been linked to the shot.

In new guidance, the European Union’s drug regulator said people should still get a second AstraZeneca dose four to 12 weeks after their first shot and that the benefits of immunization far outweighed the risks of the unusual clotting disorder.

“At this stage, the available data supports continuing to give a second dose of the vaccine,” Noël Wathion, the agency’s deputy executive director, said.

In this Wednesday, April 14, 2021 file photo, a box with vials of AstraZeneca vaccine against COVID-19 is shown in Amsterdam, Netherlands.

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The agency said it wasn’t known whether the risk of a rare blood clot after a second dose might be different than that engendered by the first shot.

In its analysis of Europe-wide AstraZeneca data, the EMA also said there wasn’t enough information to know who might be more susceptible to the unusual clots.

Earlier this month, the Amsterdam-based drug regulator for the 27-nation EU said there was a “possible link” between the AstraZeneca vaccine and rare blood clotting disorders, but that the benefits of getting the shots outweighed the risks.

The EMA previously described the clots as “very rare” side effects and said the vaccine labels should be modified so doctors and patients are aware of that.

It’s still unclear exactly how frequently the rare blood clots occur. According to data from the U.K., which has administered more AZ vaccines than any other country, there were 30 such cases among 18 million inoculations, as of late March.

Last month, more than a dozen countries, mostly in Europe, suspended their use of the AstraZeneca jab over the blood clot issue. Most restarted – some with age restrictions – after the EMA said countries should continue using the vaccine.

The agency this week identified a similar possible link between blood clots and the COVID-19 vaccine developed by Johnson & Johnson. As with the AstraZeneca product, the EMA recommended labeling changes but said the benefits of getting vaccinated outweighed the risks. To date, most of the rare clotting disorders have been reported in women aged under 60.

Both the AstraZeneca and J&J vaccines are made using similar technology, and it’s still unclear whether that might be partly responsible for the rare clotting disorders.

“We don’t know yet what is the mechanism behind these rare events,” Dr. Marco Caveleri, the EMA’s head of vaccines strategy. He said the agency was starting investigations to try to discern what might be behind the blood clots.

In early April, France said people under 55 who received a first dose of the AstraZeneca vaccine should get other vaccines for their second shot because of the rare clotting risk. Sweden also said people under 65 who had gotten a first AstraZeneca shot would get a different vaccine for their booster shot.

Although a research study began in the U.K. earlier this year to test whether it’s safe and effective to mix and match different vaccines, including those made by AstraZeneca and Pfizer-BioNTech, no results are yet available.

Some scientists say it’s too early to tell whether mixing vaccines is a wise strategy.

“We are at the limits of where science can give us reliable answers on that,” said Stephen Evans, a vaccines expert at the London School of Hygiene and Tropical Medicine. He said the data published so far on the AstraZeneca vaccine prove it is helping to stop COVID-19 and that there is no evidence suggesting it shouldn’t be used.

Any restrictions to limit the use of the AstraZeneca vaccine could be disastrous for the global immunization campaign. The U.N.-backed campaign known as COVAX, which is aiming to distribute coronavirus vaccines to poorer countries worldwide, is heavily dependent on the AstraZeneca shot.


Mike Corder in The Hague, Netherlands, contributed to this report.