New Delhi: Four more countries in Europe have paused their rollouts of the AstraZeneca COVID-19 vaccine candidate after reports of unusual blood clots among its recipients across Europe.
The suspension is crucial because these countries – France, Germany, Italy and Spain – are among the largest in Europe, and their decision “marks a new crisis in confidence for an affordable vaccine,” BuzzFeed News reported.
Their decision follows similar ones by a clutch of smaller countries last week, including Denmark, Norway and Iceland. The four were also joined by Latvia, Portugal and Slovenia.
These countries’ governments seem to be acting out of an abundance of caution considering medical experts are yet to find a causal link between the vaccine candidate and these blood clots.
The prevalence of such cases is also very low. On March 11, the European Medicines Agency (EMA) said in a statement that there had been 30 “thromboembolic events” among 5 million people who had received the AstraZeneca vaccine.
According to BuzzFeed News, AstraZeneca has acknowledged 37 cases of two conditions caused by blood clots – pulmonary embolism and deep-vein thrombosis.
Quoting from a study published in 2019, “Acute venous thromboembolism, including deep vein thrombosis and pulmonary embolism” has “an annual incidence of approximately 1 or 2 cases per 1,000 persons.”
If the AstraZeneca vaccine was directly causing the clots, a liberal prevalence of 0.02% for the two conditions implies 10,000 cases, with a base population of 5 million recipients. (Note that this is an illustration and not a technical assessment.)
So 30-40 cases of these conditions is considered low, and is part of the EMA’s current position that “the vaccine’s benefits continue to outweigh its risks and the vaccine can continue to be administered” even as its safety committee investigates “cases of thromboembolic events”.
The EMA is also expected to hold a special meeting on March 18, Wednesday, on the issue.
There have been reports that India’s vaccine regulators are also expected to review the AstraZeneca shot this week. N.K. Arora, a member of the National COVID-19 Task Force, has said that the group is considering the post-vaccination data.
Like in Europe, Arora said that the number of cases of unusual clotting-related conditions is “very, very low” among those who received the AstraZeneca vaccine.
He estimated that there are “50 or 60 cases” at a time when India had delivered 21 million doses of both Covaxin and the AstraZeneca candidate, called Covishield in India. There have been no similar reports thus far vis-à-vis the effects of Covaxin.
“We do not want people to panic and we would, for the time being, recommend that countries continue vaccinating with AstraZeneca,” AFP quoted WHO chief scientist Soumya Swaminathan as saying. “So far, we do not find an association between these events and the vaccine.”
India has also exported millions of doses of the AstraZeneca candidate to its neighbours and other countries, including Brazil. The WHO included it in in its list of vaccines approved for emergency use on February 15, so it will also be rolled out through the COVAX alliance worldwide.