Don't bin the AstraZeneca vaccine, says Prof Shabir Madhi
There is no need to dump the Oxford/AstraZeneca Covid-19 vaccine, as it still has an important place in SA’s fight against the coronavirus.
In fact, people at high risk of severe Covid-19 infection that could result in hospitalisation or death, should take the vaccine — first and foremost the country’s front-line health-care workers.
This is according to Wits University professor and principal investigator of the AstraZeneca vaccine trial, Prof Shabir Madhi, who was speaking on a panel hosted by Maverick Citizen on Tuesday night. Madhi said there was scientific reason to believe the shot was effective against severe Covid-19 infection, so it should still be used in SA.
He was speaking after revelations at the weekend that the vaccine was not effective against mild and moderate infection.
Madhi said on Tuesday that the majority of the Covid-19 cases of the people involved in the vaccine study in SA “ended up being mild”.
“In fact, two-thirds of the cases were mild and one-third were moderate. So we can't pronounce, using this data, whether the AstraZeneca vaccine is going to or not going to protect against severe disease. What we can say is that, against the variant that is now circulating in SA, this vaccine will not protect against mild infection in a younger age group and, certainly, probably not in older individuals as well,” he said.
However, Madhi said all indications were that the vaccine did protect against more severe forms of the disease, largely because it was similar to the Johnson & Johnson (J&J) vaccine, which did show efficacy against severe illness.
“I believe that there's a role for the AstraZeneca vaccine, not just for being rolled out in SA, but in other African countries as well. What is the basis for that? So the AstraZeneca vaccine is very similar to the J&J vaccine ... in terms of the technology that's been used to construct it. There are certain slight differences in terms of the spike protein that is expressed by what we call vectors. But beyond that, the immune responses that's induced by these in vaccines are almost identical,” said Madhi.
And because of this, he said, AstraZeneca should be used.
“Certainly, I wouldn't be advocating the AstraZeneca vaccine be used in someone who is relatively well and healthy and is not at risk of developing severe disease because this vaccine is not going to confer any sort of benefit on that individual. But for individuals with underlying risk factors, for severe disease or hospitalisation ... there’s a toss-up. And the toss-up is using a vaccine which very likely will protect against severe disease vs remaining unvaccinated into some distant time into the future when larger quantities of some other vaccine becomes available.
“So I don't think that we need to be halting the [vaccine rollout] programme, but what we can’t do is go to health-care workers and say they all should be vaccinated. Among the health-care work force, 75% probably don’t have risk factors and are not over the age which predisposes them to severe disease. So if you vaccinate all health-care workers with the AstraZeneca vaccine, 75% of the health-care force is not going to derive any benefit. Whereas, with the other 25%, there is good reason, in the absence of any other options which have been proven to work ... to vaccinate with the J&J vaccine, if it's available, and if not with the AstraZeneca vaccine.
“And then the same thing applies to the other parts of the public workforce and everyone else. People at higher risk of developing severe disease, right now there are two choices: remain unvaccinated until a resurgence appears, or take your chances with a vaccine that is known to be safe and very likely will protect against the disease and death. And that includes the AstraZeneca vaccine,” said Madhi.
Prof Glenda Gray, SA Medical Research Council CEO and principal investigator of the J&J vaccine trial, was more circumspect about the AstraZeneca rollout, and has suggested waiting for the J&J vaccine, which is likely to be more beneficial.
She said: “I view vaccinations in terms of individual and public benefit. In terms of AstraZeneca, I think we have to look at the data.’
Gray said that a clinical trial now under way into the AstraZeneca vaccine would be of huge value. In this trial, 30,000 people were being evaluated and it was “fully enrolled”.
“Why this is important is because it will give us information on severe disease and death, and people with comorbidities. One thing I would suggest is that ... we evaluate the vaccine going forward,” she said.
She said that during his state of the nation address on Thursday, President Cyril Ramaphosa was going to have to tell SA about the plans for the AstraZeneca vaccines, as the public needs to know about the doses we have acquired.
Madhi, however, says we should take our cues from the World Health Organisation which, after five hours of deliberation, concluded that there was still a major role for the AstraZeneca vaccine.
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