[ad_1]
The launch of the AstraZeneca vaccine to healthcare workers in South Africa has been temporarily halted following results showing low efficacy against the South African variant of the coronavirus.
South African healthcare workers will now receive either the Johnson & Johnson single-dose vaccine or the Pfizer vaccine, after Health Minister Dr. Zweli Mkhize announced a major change in the launch of the vaccine on Sunday, February 7. in the country.
The change was necessitated by the publication of what the lead investigator of the Oxford / AstraZeneca trial, Professor Shabir Madhi, said were “disappointing results” showing that the vaccine did not work well against the South African variant of the coronavirus.
The South African variant was first identified in November 2020 in cases from Nelson Mandela Bay. Currently, more than 90% of positive cases of coronavirus infections in South Africa are caused by this variant which has been shown to be more contagious than the parent virus.
As South Africa has already received one million doses of the Oxford / AstraZeneca vaccine with an expiration date of April, Deputy Director General of the Department of Health Anban Pillay said they are collaborating with the Serum Institute of India to find a solution. .
Madhi said data from the Oxford / AstraZeneca trial showed that the South African variant of the coronavirus exhibited some resistance to antibodies produced by an immune response to infection with the parent coronavirus and to vaccines.
He said his study involved 2,000 adults between the ages of 18 and 65 with no underlying comorbidities. “To be successful, we needed to be 60% effective.”
He said the study was not designed to test whether the vaccine will protect against severe Covid-19.
Madhi said that initial results when the parent virus was still the dominant strain in South Africa were very promising and showed high levels of protection, with the vaccine reducing the chance of becoming infected with the parent virus by up to 75%.
“It showed tremendous potential to prevent infections, mild and moderate illnesses,” Madhi said.
He explained that the new variant of the virus had a different spike protein and the vaccines that had been developed used the spike protein of the original virus to trigger an immune response, reducing efficacy.
“Unfortunately, viruses mutate. Sometimes this is by accident. But often the reason is that the virus wants to become more adept at infecting the host. “
This, Madhi explained, was what had happened with the South African variant, as well as another variant that was first identified in the UK.
“In a country like South Africa, where up to 30% of the population was infected during the first wave, the virus was under pressure. It had to evolve to ensure its survival, ”Mahdi said. “It is a way of becoming elusive to immune responses.”
He said this had important implications for the future. “This virus is likely to accompany us throughout our lives. It is unlikely to be eradicated anytime soon. ”
Madhi explained that when they tested the vaccine in the lab against the South African variant they found that the antibodies produced by the Oxford / AstraZeneca vaccine were not active against it.
“That would be reason enough to be concerned that the vaccine would not do what we set out to do,” he said.
He added that in clinical trials the vaccine had shown only a 22% lower risk of Covid-19 in the vaccinated group, but added that the data did not indicate whether the vaccine could protect against serious illness and death.
Madhi said the other clinical trial in which he is the lead investigator, the Novavax vaccine trial, had shown 60% efficacy in protecting against mild and moderate infections with the South African variant.
“It’s not all doom and gloom … we have vaccines that work,” he said, before adding that the Oxford / AstraZeneca vaccine does not work against the South African variant of the virus.
Gray said the Johnson & Johnson vaccine has been shown to protect against serious illness and death in cases of infection with the South African variant.
Madhi said the Johnson & Johnson vaccine produces an antibody very similar to the AstraZeneca vaccine and reduces the risk of mild to moderate illness by 57% and severe illness and death by 80%.
“We were very optimistic at one point,” Madhi said. “If the virus had not evolved, we would be in a very good space. The results are a reality check. We were elated. We must recalibrate our expectations. But we must also recognize that vaccines are the only sustainable option to reduce serious illness and death. “
Professor Glenda Gray, president of the Medical Research Council and principal investigator for the Johnson & Johnson vaccine, explained that her vaccine was similar to those developed for Ebola, the Zika virus, and for some of the ongoing HIV vaccine trials. in South Africa.
Gray said the Johnson & Johnson vaccine has been shown to protect against serious illness and death in cases of infection with the South African variant.
“It’s a miracle solution, but it won’t protect against sneezing,” he said.
He said the new plan is for the Johnson & Johnson vaccine to be rolled out among healthcare workers and further evaluated in the field.
“We can not wait. We already have good local data, ”he said.
He said the vaccine, which is given in a single injection, could be kept in a common bar refrigerator.
Gray said 33% of the subjects in the trial, conducted in various regions of the world, were over 65 years old and included patients with comorbidities.
Their trial took place at a time when new variants of the virus were emerging and had shown efficacy against them.
“Johnson & Johnson requested emergency use of the vaccine last week. There is ongoing filing with the South African Medical Device Regulatory Authority, with data being added all the time. “
He said they are in advanced talks to implement it among healthcare workers as an expansion of their study.
Mkhize said this does not mean that healthcare workers will be used as guinea pigs for the vaccine.
“The Johnson & Johnson vaccine has proven to be effective. We are doing an implementation study. Everyone will be vaccinated and then we will monitor what happens, ”he said.
“A single injection can stop hospitalization and death. We want to protect our healthcare workers. The fastest way to get this vaccine out is to use this program. “
Mkhize said he asked a group of scientists to tell the government what to do with the 1 million doses of the AstraZeneca vaccine that arrived in the country on February 2.
“There are no plans to return it.”
Madhi said studies are underway in the UK to look at the use of a combination of vaccines such as the Oxford / AstraZeneca and Pfizer vaccines.
“It could well be that in South Africa we explore the combination of the Johnson & Johnson and Oxford / AstraZeneca vaccines,” he added.
Madhi emphasized that if there is any evidence that the Oxford / AstraZeneca vaccine will protect against serious illness and death, it should be implemented.
“Do we want to risk not vaccinating high-risk populations because we are not sure whether it will protect against serious diseases? It will be unwise to discard the million doses with the probability that they can protect against serious diseases, ”he said.
Co-Chair of the Ministerial Advisory Committee on Covid-19, Professor Salim Abdool Karim, said that in the near future there will be a next generation of vaccines that protect against variants of the coronavirus such as the South African variant.
“AstraZeneca deployment will be suspended. We will deploy [the Johnson & Johnson vaccine] to a large enough number of people to assess hospitalization rates. We can do that because we have an established system, “he said.
Professor Barry Schoub, chairman of the Ministerial Advisory Committee on Vaccines, said the country will have to decide what it wants from a vaccine.
“The main objective is to prevent serious diseases, mortality and hospitalizations. That should be our main goal. We also want to prevent moderate illnesses, as they have an impact on the economy. We also want to prevent asymptomatic infections, as this causes infections in the community.
“In the short term, the AstraZeneca vaccine had disappointing results, but we may still be able to use it, perhaps in combination with other vaccines. We just need to discontinue the use of AstraZeneca, but do research to see if we can use it in a different way. “
Mkhize said he wanted more work done to see if the Oxford / AstraZeneca vaccine can prevent serious illness and death.
He said the Oxford / AstraZeneca vaccine was ordered before the results were published.
“We will wait for the scientists to come and tell us. They must figure it out. But we’ll stick with the vaccines for now. We will link the vaccine program with an implementation study for Johnson & Johnson. “
He said South Africa was also in negotiations to acquire the Russian Sputnik vaccine, the Chinese Sinopharm vaccine, the Modern American vaccine and will explore the acquisition of the Novavax vaccine. DM / MC
Information regarding Covid-19, vaccines, how to control the spread of the virus, and possible treatments is constantly changing. According to Regulation 11 (5) (c) of the South African Disaster Management Act, it is prohibited to publish information through any medium with the intention of misleading people about government measures to address Covid-19. Therefore, we are disabling the comment section of this article to protect both the commenting member and ourselves from potential liability. If you have additional information that you think we should know, please send an email [email protected]
Do you like what you are reading? Sign up for the Maverick Citizen newsletter and get a weekly summary delivered to your inbox every Tuesday. Free. Because paywalls shouldn’t keep you informed.
