Plan to test unused vaccines shelved

The government has shelved plans to launch an implementation study of AstraZeneca’s Covid-19 vaccine, which could potentially have answered key questions about whether it protects people from severe disease caused by the new variant dominating transmission in SA.

The health department originally planned to launch SA’s coronavirus vaccine rollout with AstraZeneca’s shot but changed its plans at the 11th hour after evidence emerged that the jab offered minimal protection against mild to moderate disease caused by the 501Y.V2 variant.

The government switched to Johnson & Johnson’s (J&J) vaccine, which it began dispensing to health-care workers on February 18.

When the government suspended the AstraZeneca rollout, it said it might use some of the 1.5-million doses it had already procured from the Serum Institute of India to determine

whether they did at least protect people from severe illness and death from Covid-19.

The ministerial advisory committee on Covid-19 vaccines discussed whether to launch a phase 3b study of the AstraZeneca shot and decided against it, committee chair Barry Schoub confirmed to Business Day. “We have limited resources, which at the moment would be better served looking at other issues,” he said.

Helen Rees, executive director of the Wits Reproductive Health and HIV Institute and a member of the vaccine advisory committee, said there were also practical problems because the vaccines SA had procured from the Serum Institute of India will expire at the end of April.

A phase 3b implementation study would have needed to cover 100,000 volunteers and each would have needed two doses, ideally spaced between eight and 12 weeks apart. “Time was against us,” she said.

Many scientists are hopeful the AstraZeneca shot will protect people from severe illness and death because it uses the same adenovirus vector technology as the vaccines developed by J&J and Novavax.

Phase 3 trial data for both the J&J and Novavax shots showed no hospitalisations or deaths from Covid-19 among vaccine recipients.

Wits health dean Shabir Madhi, who led a phase 2 trial of AstraZeneca’s vaccine in SA, said earlier this week there was “every reason to believe” it will protect people from severe disease. Given that SA’s vaccine rollout is unlikely to reach a significant portion of the population before the next surge in infections, there was nothing to be lost by dispensing the shot to vulnerable people, he said.

“Get people to volunteer, and the worst-case scenario is it doesn’t work and those same individuals get vaccinated when another is available. Leaving them unvaccinated in the face of a surge will [lead to] more deaths,” he said in a virtual event hosted by the Wits Business School. He had not responded to Business Day’s request for comment at the time of publication.

2 the number of doses that would have to be given to each of the 100,000 volunteers

12 the maximum weeks between each dose