Single-shot Covid-19 vaccine could be here by next year

A Covid-19 vaccine could be available as early as next year, with Johnson & Johnson moving to the final stage of clinical trials for a single-shot dose, and South Africa is expected to participate.

The single-shot vaccine is being developed by Johnson & Johnson’s Janssen Pharmaceutical Companies, and the trial will study the safety and efficacy of a single vaccine dose compared to a placebo, when it comes to preventing Covid-19.

The study would aim at obtaining representations of populations which were disproportionately impacted by the pandemic, taking part across three continents which aimed to enroll participants from South Africa, United States, Argentina, Brazil, Chile, Colombia, Mexico and Peru.

The Phase 3 ENSEMBLE clinical trial will enroll up to 60 000 adult participants, including significant representation from those over the age of 60,and both those with and without comorbidities associated with an increased risk of severe Covid-19.

“With our vaccine candidate now in our global Phase 3 trial, we are one step closer to finding a solution for Covid-19. We used a highly scientific and evidence-based approach to select this vaccine candidate,” said Global Head at Janssen Research and Development, Mathai Mammen.

Unlike other vaccines that need to be frozen, the single-shot trial is estimated to remain stable for at least three months at between 2-8˚C and up to two years if stored at -20˚C, simplifying the distribution of the vaccine candidate as new infrastructure would not be required, said the company.

Should the trial be successful, safe and effective, it would be available in early 2021 on a “not-for-profit base” for authorised “emergency pandemic use”.

“Johnson & Johnson has continued the scaling up of its manufacturing capacity and remains on track to meet its goal of providing one billion doses of a vaccine each year,” said Johnson & Johnson.

But while candidate vaccines might be successful, they might only work for a short period of time, said epidemiologist Professor Jo Barnes.

It is possible that such vaccines might have to be manufactured at double volume if patients need to return for a second shot once the first one wears off. This is because Covid-19 is still a new virus with complexities, she said.

“I suspect the vaccines will work, but not very strongly. We may have to give people two shots – the vaccine and a little while later, a booster shot. [This] will double the cost and [people] would have to come in twice for government to give them two [shots]. This is a possibility unless it’s a smart and successful vaccine. The more we learn about this virus, we realise the more complex it is.

“We may find it works for certain groups and not well for others,” said Barnes.

rorisangk@citizen.co.za

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