South Africa Suspends AstraZeneca Covid-19 Vaccine Over Variant Concerns

South Africa will suspend the use of one of the Covid-19 vaccines of which New Zealand has pre-purchased millions of doses, fearing that it will not fully protect against a new variant.

The move came in the wake of a new analysis, to be published ahead of peer review, which found that Oxford-AstraZeneca’s ChAdOx1 vaccine provided only minimal protection against mild-to-moderate Covid-19 variant infection. coronavirus B.1.351 (South Africa). .

The variant, first identified in South Africa in mid-November, has since been confirmed in cases along the New Zealand borders.

The analysis, conducted by the Wits Vaccines and Infectious Diseases Analytics (VIDA) Research Unit that runs the Oxford Covid-19 vaccine trial in South Africa, involved about 2,000 volunteers, with an average age of 31 years.

The tests did not focus on protection against moderate to severe disease, hospitalization or death, as the vaccine target population was at low risk.

The results showed that while the vaccine was highly effective against the original variants of the non-B.1.351 coronavirus in South Africa, its effects on the new strain were substantially reduced.

South Africa had planned to give healthcare workers the injection soon, having received about a million doses, but would now offer other vaccines from Johnson & Johnson and Pfizer.

Work was already underway at Oxford University to produce a second generation of the vaccine, which has been adapted to target variants with mutations similar to B.1.351.

The principal investigator of the VIDA trial, Professor Shabir Madhi, said the findings forced scientists to “recalibrate” thinking about how to tackle the virus and shift the focus from herd immunity to protecting all people at risk.

Professor Andrew Pollard, principal investigator for the Oxford vaccine trial, said the study confirmed that the coronavirus would find ways to continue to spread in vaccinated populations.

“But if you take into account the promising results of other studies in South Africa, such as those using a similar viral vector, vaccines can continue to reduce the number of victims in health care systems by preventing serious diseases.”

Oxford vaccine professor Sarah Gilbert said her colleagues were working with AstraZeneca to optimize the pipeline required for a strain switch should it become necessary.

“This is the same problem that all vaccine developers face, and we will continue to monitor the emergence of new variants that emerge in preparation for a future strain switch.”

It was not yet clear what the development might mean for New Zealand’s vaccine strategy.

Under its pre-purchase agreement, New Zealand has signed up to receive around 7.6 million doses of the Oxford-AstraZeneca vaccine, enough for 3.8 million people.

On Friday, it was reported that New Zealand could receive nearly 250,000 doses of the vaccine by July, as part of its membership in the global Covax alliance.

“We are constantly receiving clinical data on AstraZeneca from the company itself and other foreign regulators,” a Health Ministry spokesman told the Herald today.

“The widespread deployment of the AstraZeneca vaccine overseas will help us understand the benefits to the general population, including the degree of protection and whether the vaccine can reduce transmission of the virus and its variants, including the South African variant.”

University of Auckland Vaccine Associate Professor Helen Petousis-Harris said it would be “disappointing” if the vaccine did not work as well in the variant, as reported, but cautioned that only limited data was available.

“I think we have to let this play out and wait until we’ve seen all the data,” he said.

“But it is encouraging that [AstraZeneca] he’s able to go back and adjust the formulation. “

The University of Otago and ESR virologist Dr. Jemma Geoghegan said it would be important to see how the vaccine worked in a broader context, given that the initial trial focused primarily on younger people without a serious infection.

“But this new South African variant has some mutations that work to escape or evade the vaccine, which is concerning,” he said.

“So it’s good that these studies are done in real time.”

Geoghegan said it remained to be seen whether the South African variant would become dominant around the world.

“At the moment it appears that variant B.1.1.7, which is the most prevalent in the UK, is increasing in frequency everywhere at the moment.”

The latest development pointed to one of the “rays of light” that New Zealand could draw from being at the bottom of the vaccine row, he said, giving the country more time to see how injections work in other countries.

New Zealand has previously purchased three other vaccines, from Pfizer and BioNTech; Janssen Pharmaceutica; and Novavax.

The first purchase agreement was for 1.5 million vaccines from Pfizer and BioNTech, which MedSafe granted interim approval for last week.

There are enough vaccines for 750,000 people and each person will need two doses of this vaccine, one month apart.

An agreement in principle has been signed with Janssen Pharmaceutica to purchase up to 5 million vaccines, probably in a single dose.

In December, the government signed a new agreement with Novavax to buy 10.72 million doses of its vaccines, enough for two doses for 5.36 million people, but this is not expected until the end of this year.

“These vaccines are on three different technology platforms to ensure that we have diversity in the types of vaccines available,” a ministry spokesman said of the current agreements.

“Our approach also allows for the possibility that some vaccines may be more suitable for certain population groups or for deployment in different areas.”

The spokesperson stressed that Medsafe was conducting robust evaluations of the Covid-19 vaccines to ensure they were safe and effective.

“No vaccine, including AstraZeneca, will be available for public use in New Zealand until it has completed the Medsafe evaluation process and has been approved as safe for use here.”