Governments Still Confident in AstraZeneca Vaccine Despite Troubling Results Against South African Variant

Despite new study findings suggesting that the AstraZeneca (AZ)/University of Oxford COVID-19 vaccine provides only “minimal protection” against mild-to-moderate infection from the South African variant, Western governments still have faith in the vaccine as a valuable weapon against the pandemic.

According to an analysis by researchers leading the Oxford COVID-19 vaccine trial in South Africa, the vaccine showed minimal protective effect against mild-to-moderate COVID-19 infection from the fast-spreading South African variant. Oxford said that the early data, which still must be peer-reviewed, “appear to confirm the theoretical observation that mutations in the virus seen in South Africa will allow ongoing transmission of the virus in vaccinated populations.”

The analysis did not evaluate the strain’s impact on transmission of severe disease, but a previous assessment found that the AZ vaccine fully shielded against severe disease, hospitalization and death more than 22 days after the initial shot (DID, Feb. 4).

The most recent findings, despite encompassing a relatively small number of mostly younger patients (approximately 2,000 patients aged 31 on average), has prompted South Africa to pump the brakes on vaccine rollout there in order to further evaluate it.

In the meantime, the government aims to speed up delivery of Johnson & Johnson’s vaccine although it has yet to receive regulatory authorization in the country. The first shots could reportedly arrive near the end of the week.

Western governments are not put off by the findings, stressing their belief that the AZ vaccine still confers great benefit, including protection against severe COVID-19 and death.

“We’re very confident in all the vaccines that we’re using, and I think it’s important for people to bear in mind that all of them, we think, are effective in delivering a high degree of protection against serious illness and death, which is the most important thing,” said UK Prime Minister Boris Johnson.

Similarly, Australia’s Health Minister Greg Hunt said that no evidence exists to suggest coronavirus variants impede the AZ vaccine’s main goal of preventing severe COVID-19.  French Health Minister Olivier Veran also signaled support for the vaccine, contending that the inoculation protected against “nearly all the variants” and “reinforces and amplifies our vaccine strategy.”

An AZ spokesperson told FDAnews the company believes its vaccine will protect against severe COVID-19 caused by the South African strain, “as neutralizing antibody activity is equivalent to that seen with other COVID-19 vaccines that have demonstrated activity against more severe disease and particularly when the dosing interval is optimized to eight to 12 weeks.”

“We are working closely with the South African Ministry of Health on how best to support the evaluation of [our] COVID-19 vaccine … against severe disease of the [South African] variant and how to bring this vaccine to the South African people,” the AZ spokesperson said.

AZ and Oxford are currently developing a revamped vaccine tailored toward protecting against new coronavirus mutations and believe it will be ready in the fall. — James Miessler