- After AstraZeneca, the COVID 19 Vaccine failed to stop the new virus variant in South Africa, the country has halted its plans to launch its first immunization campaign planned for next week.
- The South African placebo-controlled trial of the vaccine, conducted in about 2000 people recorded a less than 25% efficacy against mild and moderate disease, and did not meet minimal international standards for emergency use.
After AstraZeneca, the COVID 19 Vaccine failed to stop the new virus variant in South Africa, the country has halted its plans to launch its first immunization campaign planned for next week.
The South African placebo-controlled trial of the vaccine, conducted in about 2000 people, recorded a less than 25% efficacy against mild and moderate disease and did not meet minimal international standards for emergency use. The AstraZeneca-Oxford vaccine trial was run In South Africa from June to November 2020. Two weeks after the second dose -when participants were supposed to acquire full immunity, 19 cases of mild or moderate disease developed among the vaccinated, versus 23 in the placebo group, resulting in an efficacy of 21.9%. That is far below the 50% minimum required for emergency use authorization in many countries.
COVID-19 vaccines made by Johnson & Johnson (J&J) and Novavax also could not offer the required protection against B.1.351 / 501.V2, the SARS-CoV-2 variant that is widely prevalent in South Africa. The vaccines’ efficacy against mild cases in South Africa was 57% for J&J and 49% for Novavax—lower than in any other country they were tested.
The makers of the vaccine, AstraZeneca and the University of Oxford, had hoped that their vaccine will be widely used in developing countries with its favourable pricing at 3$each, far below the price of any other vaccine offering protection against COVID 19.
Shabir Madhi of the University of the Witwatersrand, the principal investigator of the trial said at a press conference that South Africa has to recalibrate its expectations as well as response to COVID-19 vaccines and hoped that AstraZeneca vaccine will also eventually prove useful to fight the Pandemic. Antibodies triggered by the J&J vaccine and the AstraZeneca were reportedly “very similar,” as the two vaccines are based on a similar technology, he said. The J&J vaccine, which was put to the test, c protected against severe disease and death, even against the B.1.351 variant. It was reported that South Africa proposes to roll out the AstraZeneca-Oxford vaccine in a phased manner, first assessing its impacts on hospitalization rates in the first 100,000 people who receive it.
At a World Health Organization (WHO) press conference that reviewed the new findings at length, a chorus of scientists and public health experts expressed confidence that the AstraZeneca-Oxford vaccine may still play an important role in South Africa and elsewhere. Meanwhile, the Oxford team said that it has already started to work on a second-generation vaccine that targets the mutated spike protein of the B.1.351 variant.
