South Africa immediately copied the American pause on Johnson & Johnson vaccinations, infuriating doctors who are still clamoring for shots, especially in remote parts of the country. In February, health officials dropped the AstraZeneca vaccine over its limited efficacy against a dangerous variant there.
To date, only half of 1 percent of the population is vaccinated, and a mere 10,000 shots are being given each day. At that rate, it could take weeks, if not longer, for a single rare blood clotting case to emerge, said Jeremy Nel, an infectious disease doctor in Johannesburg. He was dismayed by the decision to pause shots, given the risk to vaccine confidence in a country where two-fifths of the people say they have no intention of being vaccinated.
“The slower you go, that failure is measured in death,” Dr. Nel said. “Even if you delay for a week, there is a non-trivial chance that will cost lives.”
The solution in many European countries — to stop using seemingly riskier vaccines in younger people, who are at lower risk from Covid-19 — would be unworkable in Africa, where the median age in many countries is below 20.
And any further restrictions would compound the hurdles facing Covax, among them a paucity of funding for every part of inoculation programs beyond the touchdown of doses at airports.
Mali, in western Africa, has administered 7 percent of the AstraZeneca doses that Covax has delivered. Sudan, in eastern Africa, has given 8 percent of the doses it has received.
Skittishness over the AstraZeneca and Johnson & Johnson vaccines, analysts fear, could stoke demand for Russian- and Chinese-made shots about which far less is known. As it is, some global health officials have turned their attention to the Novavax vaccine, which is not yet authorized but makes up a third of Covax’s portfolio.