South Africa recently received 1 million doses of the AstraZeneca-Oxford COVID-19 vaccine and was ready to begin vaccinating health care workers, but yesterday health officials announced a pause in the rollout to provide early results study that offer little protection against mild to moderate diseases caused by the country’s dominant strain of B1351 variant

New questions about the vaccine come as World Health Organization (WHO) advisers consider the emergency listing this week, which, if approved, would pave the way for lower-income countries to receive their first doses through the COVAX program First deliveries via COVAX depend on 350 million doses of AstraZeneca-Oxford vaccine

The new findings from a preprint submitted are from researchers in South Africa and the United Kingdom. The study included 2000 volunteers with an average age of 31 years. In addition to minimal protection against mild to moderate illnesses, they also found that virus neutralization against the B1351 variant was significantly lower than the standard virus

However, the team said they were unable to assess protection from serious illness, hospitalization, and death because the study target audience was younger and at low risk for these results

In a press release from the University of the Witwatersrand in Johannesburg, the team said efforts are being made at Oxford to manufacture a version of the second generation vaccine that will target variants similar to B1351

Andrew Pollard, MBBS, PhD, chief investigator for the Oxford Vaccine Study, said the study confirms that the virus will find ways to continue to spread, as expected, in vaccinated populations, but shows promising results from other vaccine trials in South Africa with a similar virus vector suggests that vaccines continue to provide relief to health systems by preventing serious illnesses

At a WHO briefing today, Dr med Salim Abdool Karim, co-chair of the South African COVID-19 Advisory Committee, said concerns about the vaccine’s effectiveness against the B1351 variant deepened after Novavax reported 89% effectiveness in the UK but only 49% in South Africa

He said officials had halted the launch of the AstraZeneca-Oxford vaccine to collect more clinical data to better understand the vaccine’s effects, especially given the uncertainty about its effects on serious diseases

He said there were some reservations about the new results from the South African study, including the fact that the number of participants was small and the confidence intervals were wide, with an upper limit of 60% indicating the overall effectiveness of the drug broader phase 3 approaching study He also said the dosing interval in the study was short compared to newer longer intervals suggested by AstraZeneca to improve immune response

One suggestion that South African officials are considering is phasing it in, starting with 100000 people would need to be vaccinated to monitor the vaccine’s effects on serious diseases, said Abdool Karim

The B1351 variant was first found in South Africa, where it currently accounts for 80% to 90% of the cases.Together with the P1 variant detected in Brazil, it contains the E484K mutation, which is supposed to help SARS-CoV-2 evading immunity to vaccines and natural infections Scientists in the UK recently reported that a small number of B117 variants developed the E484K mutation, raising greater concerns that ongoing evolutionary changes could dampen the effects of vaccination

At today’s meeting, WHO Director General Tedros Adhanom Ghebreyesus, PhD, said the Group’s Strategic Advisory Group of Experts in Immunization (SAGE) met today to review the AstraZeneca-Oxford vaccine, and that he’ll meet tomorrow with the chairman of SAGE to discuss their recommendations

In the next few days, the WHO expects a decision on the emergency listing of the AstraZeneca-Oxford vaccine, which will be the second after that of Pfizer-BioNTech The emergency application would relate to an AstraZeneca-Oxford vaccine that is in two locations one at the Indian Serum Institute and one at SK Bioscience in South Korea

Tedros said it is becoming increasingly clear that manufacturers need to adjust to virus development, taking into account the latest variants for future vaccines, including booster shots, much like updating flu vaccines, he said it was important for that Countries continue to report variants to WHO, which expands their mechanism to provide guidance to manufacturers and countries

Seth Berkley, MD, chairman of the board of directors of Gavi, said that as science advances, health officials are learning more as they work with the vaccines, noting that discussions like the one currently being held about the AstraZeneca vaccine are expected in South Africa He said there could also be changes in the way vaccines are used and in the makeup of vaccines

While officials wait for the SAGE guidelines, it looks like the AstraZenca vaccine is effective and has been reviewed by a number of tough regulators Officials expect to continue rolling out the vaccine for COVAX while further studies are monitored

Richard Hatchett, MD, chairman of the Coalition for Epidemic Preparation (CEPI), said at today’s news conference that CEPI has announced more funding for “mix and match” studies to optimize and expand the use of existing vaccines could “strategies to improve the immune response

CIDRAP – Center for Infectious Disease Research and Policy Office of the Vice President for Research, University of Minnesota, Minneapolis, MN

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World News – FI – South Africa Suspends AstraZeneca Vaccine Launch on Various COVID Issues