Officials in South Africa said Sunday that they will pause plans to distribute the AstraZeneca vaccine after preliminary trial data suggested it was ineffective against mild and moderate cases of COVID-19 caused by the dominant strain circulating in the country.
According to The Associated Press, South Africa received 1 million doses of the AstraZeneca vaccine last week, and the country’s health care workers were scheduled to start receiving vaccinations by mid-February. But officials have now decided to put the vaccination plans on hold in light of preliminary data specific to the South Africa strain.
“The AstraZeneca vaccine appeared effective against the original strain, but not against the variant,” said Zweli Mkhize, minister of health for South Africa. “We have decided to put a temporary hold on the rollout of the vaccine … more work needs to be done.”
The study, which has not been peer-reviewed, analyzed participants between the ages of 18 and 64, half of whom received a placebo, reports The Washington Post. Twenty people who received the placebo were infected with the South Africa-dominant coronavirus strain, and nineteen people who received the vaccine candidate were infected with it.
Dr. Shabir Mahdi, the principal investigator in the trial, said the data pointed to a 10% efficacy rate against mild to moderate COVID-19 caused by the strain, but noted the data was not statistically significant, reports The Wall Street Journal. While there were no reported cases of severe COVID-19 in recipients of the vaccine candidate, researchers said it was too early to tell whether the vaccine played a role in preventing such cases.
“Protection against moderate-severe disease, hospitalization or death could not be assessed in this study as the target population were at such low risk,” said Oxford University and the University of the Witwatersrand in Johannesburg in a joint statement on Sunday, reports The Associated Press.
Researchers for the AstraZeneca vaccine said they expect to have a vaccine that can work against the South Africa strain, which researchers believe may spread up to 50% more easily than the original strain, by fall of 2021.
As The Wall Street Journal notes, two companies developing COVID-19 vaccines — Johnson & Johnson and Novavax — have said their vaccine candidates are still effective against the South Africa strain, albeit less so than against the original strain. Johnson & Johnson is currently seeking FDA emergency authorization for its COVID-19 vaccine in the United States.
As The Daily Wire previously reported:
The company’s COVID-19 vaccine candidate was 66% effective at preventing moderate to severe COVID-19 28 days after recipients received the first and only dose, according to a summary released by the company. Johnson & Johnson also said the vaccine candidate was 85% effective at preventing severe disease, and no one was hospitalized for COVID-19 beginning a month after receiving the shot. The trial data was based on 43,783 participants.