Australia and the Philippines limited the use of AstraZeneca's COVID-19 vaccine on Thursday (April 8) while the African Union dropped plans to buy the shot, dealing another blow to the company's hopes to deliver a vaccine for the world.
The shot, which is developed with Oxford University and considered a frontrunner in the global vaccine race - has been plagued by safety concerns and supply problems since Phase III trial results were published in December, with Indonesia the latest country forced to seek doses from other developers.
The Philippines suspended the use of AstraZeneca shots for people below 60 after Europe's regulator said on Wednesday it found rare cases of blood clots among some adult recipients, although the vaccine’s advantages still outweighed its risks.
Australia recommended those under 50 get Pfizer's candidate in preference to AstraZeneca's, a policy shift that it warned would hold up its inoculation campaign.
The African Union says it is now exploring options with Johnson & Johnson having dropped plans to buy AstraZeneca's vaccine from India's Serum Institute.
AstraZeneca's vaccine is by far the cheapest and most high-volume launched so far, and has none of the extreme refrigeration requirements of some other COVID-19 vaccines, making it likely to be the mainstay of many vaccination programs in the developing world.
But more than a dozen countries have at one time suspended or partially suspended use of the shot, first on concerns about efficacy in older people, and now on worries about rare side effects in younger people.
That, coupled with production setbacks, will delay the rollout of vaccines across the globe as governments scramble to find alternatives.