By Saptak Datta
South Africa has rejected the Oxford-AstraZeneca COVID-19 vaccine, one of the only two vaccines approved by India, as it is concerned with its efficacy.
The African nation had already imported one million doses of the vaccine manufactured by the Serum Institute of India near Pune in the southern state of Maharashtra. Each vaccine dose cost $5.35. After halting a planned rollout of the AstraZeneca vaccines, the nation started administering Johnson & Johnson COVID-19 vaccines that are yet to be authorized. They are being rolled out for the first time outside a major clinical trial.
“We will not be taking more doses of the AstraZeneca vaccine at this stage due to concerns about its efficacy,” Anban Pillay, deputy director-general, health ministry, South Africa, said.
“We have not returned the doses to Serum Institute but are sharing them with countries on the African continent via the African Union,” Pillay said.
A new South African variant of coronavirus was first reported in December 2020. Reports by the World Health Organization states it has higher transmissibility and is more susceptible to younger persons. There is no evidence that it is deadlier than the other variants.
A placebo-controlled phase I/II trial was conducted by South Africa’s University of Witwatersrand in collaboration with Oxford University. The study recruited 2,000 relatively healthy and young volunteers with a median age of 31 years and with few comorbidities.
The trial aimed to assess the safety, immunogenicity, and efficacy of the AstraZeneca vaccine for the prevention of COVID-19 caused by the new variant. The efficacy of the vaccine against mild and moderate COVID-19 disease was 21.9%. This was below the minimal efficacy threshold of 50% recommended for emergency use of a vaccine candidate.
On asking about the efficacy of the vaccination, Serum Institute declined to comment.
“The variant has significant changes on the spike protein, which seems to allow it to escape antibody response and affect vaccine effectiveness. The Johnson & Johnson vaccine seems to be effective despite the development of the variant,” Pillay said.
AstraZeneca said its vaccine could protect against COVID-19 given that the neutralizing antibody activity was equivalent to that of COVID-19 vaccines that have demonstrated protection.
However, African Centers for Disease Control and Prevention recommended other countries to practice caution while handling AstraZeneca against the South African variant of the virus, and suggested other shots be prioritized.
The World Health Organization, meanwhile, approved the rollout of the AstraZeneca vaccine through Covax, which aims to accelerate the development and manufacture of COVID-19 vaccines, and to guarantee fair and equitable access for every country in the world. The authorization will allow Serum Institute to begin supplies under the WHO-backed Covax initiative.
“The [AstraZeneca] vaccine was reviewed on Feb. 8 by WHO’s Strategic Advisory Group of Experts on Immunization (SAGE), which makes recommendations for vaccines’ use in populations (i.e. recommended age groups, intervals between shots, advice for specific groups such as pregnant and lactating women). The SAGE recommended the vaccine for all age groups 18 and above,” the WHO said.
“Like the AstraZeneca jab, Johnson & Johnson’s vaccine was tested in South Africa,” said Shailendra K Saxena, Vice Dean, Centre for Advanced Research, King’s George Medical University in Lucknow, Uttar Pradesh.
“A randomized multicenter, double-blinded controlled trial on safety and efficacy of the AstraZeneca vaccine in HIV-uninfected people in South Africa was performed, which showed that a two-dose regimen of the vaccine did not show protection against mild-moderate Covid-19 due to the UK variant,” he said.
“This trial produced lower efficacy rates than others Johnson & Johnson conducted around the world—57 percent protection against moderate to severe infections, compared with 66 percent in Latin America, and 72 percent in the U.S.—but it appears to be able to handle the South African variant of the coronavirus more ably than AstraZeneca’s offering.”
In India, four people have tested positive for the South African variant and one has tested positive for a Brazilian variant. “They have been quarantined and their contacts checked,” said Saxena.
“India has so far reported about 187 cases of a UK variant. Five states — Kerala, Maharashtra, Punjab, Chhattisgarh, and Madhya Pradesh — have been witnessing an upsurge in daily cases amid rising fears of the spread of new variants from South Africa and Brazil, whose first cases were reported on Feb. 16.”
These people returned from the African continent; one from Angola, one from Tanzania, and the other two from South Africa. They entered India in January 2021.
“FDA-authorized vaccines remain effective in protecting the American public against currently circulating strains. However, if there is an emergence of SARS-CoV-2 variant(s) in the U.S. that are moderately or fully resistant to the antibody response elicited by the current generation of Covid-19 vaccines, it may be necessary to tailor the vaccines to the variant(s),” the US FDA said on Feb. 22.
“Further discussions will be necessary to decide whether in the future, modified Covid-19 vaccines may be authorized without the need for clinical studies,” it said.