The government is scrambling to reorient its Covid-19 vaccination plans after new evidence emerged on Sunday that AstraZeneca’s vaccine does not protect people against mild to moderate disease caused by the new variant detected in SA late last year. This vaccine is the cornerstone of the first phase of SA’s Covid-19 immunisation strategy.
"It is a temporary issue, until we figure out the next steps," health minister Zweli Mkhize said in a late night briefing. "The plan is to find out from scientists how to use it going forward."
Meetings will be taking place on Monday with local and international scientists to chart the way forward, said the chair of the minister’s advisory committee on Covid-19 vaccines, Barry Schoub.
The government has decided that it will continue with the vaccine rollout for health workers but will start with the Johnson & Johnson (J&J) vaccine. It is awaiting scientific advice on whether the AstraZeneca shot will protect people from severe disease, hospitalisation and death before continuing with administration. The safety of the vaccine has already been established.
At the same time, scientists are planning to expedite the use of J&J’s vaccine, evaluating that too in the field, said scientists on the briefing.
Wits University confirmed on Sunday that preliminary analysis indicates the Oxford-AstraZeneca coronavirus vaccine does not protect people against mild to moderate infection with the variant detected in SA late in 2020.
Transmission
The results also appear to confirm scientists’ fears that the mutations in the variant will allow transmission of the virus even among people who have been vaccinated.
"These findings … force us to recalibrate thinking about how to approach the pandemic virus and shift the focus from the aspirational goal of herd immunity against transmission to the protection of all at-risk individuals against severe disease," said Shabir Madhi, professor of vaccinology at the University of the Witwatersrand, and principal investigator of the SA arm of international trials of the Oxford-AstraZeneca vaccine.
SA’s Covid-19 vaccination strategy currently aims to reach 40-million adults to achieve population immunity, at an estimated cost of between R12bn and R20bn.
The first phase aims to administer vaccines to SA’s 1.25-million health-care workers.
Last Monday, SA received its first 1-million doses of the AstraZeneca shot from the Serum Institute of India (SII), with another 500,000 expected later in February. It has been allocated a further 2.9-million doses of AstraZeneca’s vaccine via the Covax facility in the coming months, along with 117,000 doses of Pfizer’s vaccine, which are expected at the end of the month.
On Sunday, Wits University released a statement confirming a Financial Times report that preliminary data indicated a two-dose regimen of the Oxford-AstraZeneca vaccine provided "minimal protection" against mild to moderate infection with the B.1.351 variant, also known as 501Y.V2, among SA trial participants.
The study, which has yet to be peer reviewed, did not assess the vaccine’s efficacy against severe Covid-19, hospitalisation or death, as the study population was at low risk, said Wits.
Mutations
The study involved 2,000 volunteers with an average age of 31. It is expected to be published later this week as a pre-print, ahead of publication in a peer-reviewed journal.
The findings appear to confirm that "the theoretical observation that mutations in the virus seen in SA will allow ongoing transmission of the virus in vaccinated populations, as has been recently reported in those with prior infection", the statement said.
A spokesperson for AstraZeneca said in response to questions: "We do believe our vaccine will still protect against severe disease, as neutralising antibody activity is equivalent to other Covid-19 vaccines that have demonstrated activity against more severe disease, particularly when the dosing interval is optimised to eight to 12 weeks."
Wits said work is already under way at the University of Oxford and in conjunction with partners to produce a second generation of the vaccine, adapted to target variants of the virus with similar mutations to the SA strain, should it be needed.
SA has also been working to access alternative vaccines and has secured 9-million doses from J&J, as well as a further 20-million doses from Pfizer.
Update: February 8 2021
This story has been updated to include the government's decision to continue with the rollout of the J&J vaccine for health workers.
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