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‘Next generation’ vaccines being developed in SA

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Two Covid-19 vaccines being refined in the country have the potential to outsmart current and future variants – strengthening the fight against the pandemic.

File picture: Reuters

TWO COVID-19 vaccines are being refined in the country with the potential to outsmart current and future variants – strengthening the fight against the pandemic.

Shantivax and had5 are considered to be the “next-generation” Covid-19 vaccines.

GENLAB, a Gqeberha (formerly Port Elizabeth) based immunotherapy company, and Danish biotechnology company Immunitrack are behind Shantivax – the first Covid-19 vaccine of African origin.

The had5 Covid-19 vaccine was designed by Immunitybio Inc, an immunotherapy company from California with a lineage in cancer treatments, along with researchers from the University of Cape Town.

Most of the current Covid-19 vaccines trigger an immune response resulting in antibodies but both the Shantivax and had5 vaccines aim to additionally elicit a T-cell immune response.

A T-cell response is meant to destroy the virus.

Professor Barry Schoub, virologist and chair of the ministerial advisory committee on Covid-19 vaccines, explained that the immune system has two branches.

“There is B-cell immunity which produces antibodies and T-cell immunity which governs recovery from infection but also protection as it prevents the virus from multiplying in cells that get infected. The current concern is that variants can escape neutralising antibody responses, so a joint B-cell and T-cell response create a wider net that can be cast over a wider range of current and future variants as the result of a multi-layered immune response. A supplementary T-cell booster could go part and parcel with current vaccines as a possible way forward,” said Schoub.

Immunitybio chief executive Patrick Soon-Shiong said results had been promising and discussions were under way for their vaccine to be integrated into the Sisonke Programme that is rolling out the Johnson & Johnson vaccine.

“Time is of the essence; at great personal expense we have given ourselves the manufacturing capacity to produce millions of these capsule supplements derived from our vaccine that trigger a T-cell response. They can be kept at room temperature, taken orally and transported with less hassle than current vaccines. In primate studies, those that received the boost showed transmission immunity in the nose and lungs plus the virus stopped growing. All we need is the go-ahead from the powers that be,” he said.

Soon-Shiong was born in Gqeberha and said he made a personal promise to return to the country with resources and technology.

“I think the country’s scientists and the current infrastructure is some of the best and most sophisticated in the world, that is why I brought our vaccine to the country. I still consider myself a South African and believe we have the human capital but capacity needs to increase and that is where I want to help the nation grow.”

Professor Graeme Meintjes from the University of Cape Town, along with his team, oversaw the local branch of the had5 vaccine.

“We have been planning this clinical trial since July. They approached us to conduct clinical development of the vaccine in parallel with the US. There are 25 team members including doctors, nurses, pharmacists, counsellors, a community team and administrators who are led by myself as clinical research site leader and Amy Ward the principal trial investigator,” he said.

Meintjes said Cape Town’s Biovac Institute was collaborating on the trial and locally stored the test products but the long-term plan was that they would be involved in locally manufacturing.

Morena Makhoana, chief executive of the Biovac Institute, confirmed active discussions were had with global pharmaceutical companies regarding local manufacturing and production of Covid-19 vaccines but was unable to disclose the nature of these discussions.

The South African Health Products Regulatory Authority’s (SAHPRA) Yuven Gounden said an application to conduct clinical trials for the had5 T-cell vaccine was received in the last quarter of 2020 and approval was granted on January 12.

Kamsellin Chetty, chief executive of GENLAB, said Shantivax was still in the preclinical testing phase.

“Simply put we are in pre-human testing. SAHPRA only checks clinical or human testing but we submit our scientific data for approval and follow strict ethical scientific guidelines to ensure efficacy and maximum safety. We are a next-generation vaccine which means we have learnt from the mistakes of others and evolved to be better. We adapted to mitigate the emergence of variants,” he said.

The new Covid-19 variant discovered in New York is not as much of a concern for the country says the co-chair of the ministerial advisory committee.

Professor Salim Abdool Karim said the B.1.526 Covid-19 variant discovered in New York was not as concerning when compared to the 501Y. V2 variant discovered in South Africa last year.

“The variant found in New York has similarities to the variant that was found locally, which is that both variants have an E484K mutation which assists the virus in circumventing the immune system. The concern in the US is that should the variant spread, it would lead to reinfection. But the variant that we have been fighting has two additional mutations and this is why the 501Y.V2 is more concerning than the B.1.526,” he said.

Abdool Karim said the precautions and measures implemented to combat the 501Y.V2 variant worked against the B.1.526 meaning the country was already prepared. The 501Y.V2 variant that was discovered by the Kwazulu-natal Research Innovation and Sequencing Platform team led by Professor Tulio de Oliveira and Richard Lessells has already proven to be more infectious due to the E484K mutation.

According to the US Consulate in Durban, the proclamation made by US President Joe Biden on January 25 that put SA on the no-flight list due to the 501Y.V2 variant remained and that no visas would be granted to non-us citizens.

However, US citizens are able to fly to and from SA but must provide a negative Covid-19 test result taken within three calendar days of travel.

In a statement this week by researchers from the Columbia University Vagelos College of Physicians and Surgeons, the prevalence of the B.1.526 was said to have steadily increased since first appearing in samples collected in November.

In January it represented about 3% of analysed samples, rising to 12.3% by mid-february. The cases they found were scattered throughout the New York City area.

Anne-catrin Uhlemann, assistant professor of infectious diseases at Columbia University’s College of Physicians and Surgeons, said an analysis of publicly available databases did not show a high prevalence of the variants identified in South Africa and Brazil in case samples from New York City and surrounding areas.

“Instead we found high numbers of this home-grown lineage,” she said.

Other researchers from the California Institute of Technology posted a recent study on biorxiv that stated researchers found Covid-19 cases caused by B.1.526 were predominantly emerging in the north-eastern US, corroborating the researchers from Columbia.