Growing concerns that AstraZeneca’s COVID-19 vaccine is causing unusual blood clots could hamper vaccination campaigns around the world, from London to Seoul.
The reviews by UK and European Union regulators – who said clots are very rare events – are another blow to the vaccine, a cheaper and easier to apply product that many nations are counting on in their bid to put end the pandemic.
Safety concerns arising from growing reports of clots in people who received the first dose could undermine confidence in it, although regulators have agreed that the benefits outweigh the risks. Despite that, many regions are turning their attention to Johnson & Johnson’s vaccine, and developers in China, Russia and elsewhere are in a difficult position with demand for doses far outstripping supply.
“Better Astra than nothing,” said Michael Kinch, a drug development expert and associate vice chancellor at Washington University in St. Louis. “In a country with little vaccination, I think there is no choice but to take it.”
Scrutiny of the vaccine, developed by AstraZeneca and the University of Oxford, has been particularly intense in Europe, where skepticism about vaccines was already increasing in places like France and Poland. The UK recommended on Wednesday that people under 30 be offered alternatives to the Astra vaccine, and EU countries have also imposed age restrictions.
Governments and regulators elsewhere are also watching closely and, in some cases, taking action. The stakes are high, with AstraZeneca’s vaccine accounting for nearly a quarter of the total deals signed by 2021, according to Airfinity, a London-based research firm.
The Covax (Center for Global Access to COVID-19 Vaccines) initiative, designed to make access to vaccines more equal globally, relies heavily on the AstraZeneca vaccine, as the Pfizer and Moderna version is more expensive and more difficult to store.
Even before the results of the latest reviews in Europe, South Korea temporarily suspended AstraZeneca vaccines for people under the age of 60.
Meanwhile, Canadian authorities are reviewing the new guideline, as well as information submitted by AstraZeneca, to determine next steps, Federal Health Ministry spokeswoman Anna Maddison wrote in an email. Canada suspended plans in late March to administer the vaccine to people under the age of 55 due to clot concerns.
Regulators believe the vaccine is safe and effective, and are letting countries make their own decisions, according to Anthony Harnden, vice chair of the UK Joint Committee on Vaccination and Immunization. Many of those countries don’t have as many alternatives.
“This is important to everyone,” he said.
Countries in Africa, such as Namibia, Ivory Coast and Senegal, said they will go ahead with plans to administer the doses as they arrive, noting comments from regulators and the WHO backing the vaccine. Cameroon had previously stopped vaccinations with the Astra vaccine.
“For Namibia, this changes nothing,” said the country’s Health Minister Kalumbi Shangula. “It has not been conclusively proven in clinical settings, so we plan to administer the vaccine as soon as we receive it.”