Vaccine ready by 2021?

SINGLE DOSE: SA TO PARTICIPATE IN TRIALS BY JOHNSON & JOHNSON

‘We may have to give people two shots – the vaccine and a booster shot.’

ACovid-19 vaccine could be available early next year as Johnson & Johnson moves to its final stage of clinical trials for a single-shot dose, with South Africa anticipated to participate.

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

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

The study aims to obtain representations of populations which were disproportionately impacted by the pandemic, taking part across three continents and enrolling participants from South Africa, the United States, Argentina, Brazil, Chile, Colombia, Mexico and Peru.

“With our vaccine candidate now in our global phase 3 trial, we are one step closer to finding a solution for Covid-19,” said global head at Janssen Research and Development, Mathai Mammen.

“We used a highly scientific and evidence-based approach to select this vaccine candidate.”

Unlike other vaccines that need to be frozen, the single-shot trial is estimated to remain stable for at least three months at between 2-8ºC and up to two years if stored at -20ºC, 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 “notfor-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,” the company said.

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

It was possible that such vaccines might have to be manufactured at double volume if patients needed to return for a second shot once the first one wore off.

This was because Covid-19 was still a new virus with complexities, said Barnes.

“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,” she added.

“[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.”

Barnes said the more they learnt about this virus, they realised the more complex it was.

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

We used a highly scientific and evidence-based approach to select this vaccine candidate.

Mathai Mammen

Global head at Janssen Research and Development