A new single-dose vaccine has been found to be 66 per cent effective against the coronavirus, 28 days after vaccination, and to offer complete protection against moderate to severe disease.
The vaccine by Johnson & Johnson’s (J&J) Belgian pharmaceutical firm, Janssen, was shown to prevent moderate and severe disease in a global phase 3 trial, and to be 85 per cent effective against severe disease, the company announced Friday.
But there are already indicative signs that the vaccine, which is among the 270million doses purchased by the African Union, is less effective against the 501Y.V2 variant predominant in South Africa.
In South Africa, 95 per cent of cases in the trial were caused by the variant, which is known to be more contagious and carries mutations that may make the virus less susceptible to the antibody immune response -- including antibodies prompted by vaccination.
“With that variant, we have a lower protection against milder forms of Covid than we did in the United States, where there were more typical circulating variants," Dr Mathai Mammen, the company's global head of research and development, told CNN.
The variant has been found in Kenya, Botswana, Ghana, the French Indian Ocean region of Mayotte, Zambia and in 24 non-African nations, the World Health Organization (WHO) noted Thursday.
The level of protection against moderate to severe disease also varied from 72 per cent in the United States, 66 per cent in Latin America and 57 per cent in South Africa, measured starting one month post-vaccination.
The onset of protection was observed as early as day 14, the company announced.
Unlike Pfizer/BioNTech and Moderna, whose two-dose regimens were both around 95 per cent effective at preventing Covid-19 in clinical trials, Johnson & Johnson’s vaccine only requires a person to get a single shot.
The data is from the phase 3 trial dubbed ENSEMBLE, which studied safety and efficacy of the jab in 43,783 participants accruing 468 symptomatic cases of Covid-19. Doses of the vaccines have already been ordered by the UK (30 million), the US (100 million) and Canada (38 million).
“These topline results with a single-shot vaccine candidate represent a promising moment. The potential to significantly reduce the burden of severe disease, by providing an effective and well-tolerated vaccine with just one immunisation, is a critical component of the global public health response,” said Paul Stoffels, vice chair of the executive committee and chief scientific officer, Johnson & Johnson.
The preliminary results came a day after another American pharmaceutical, Novavax Inc, released data showing that its vaccine was 89.3 per cent effective in a trial conducted in the United Kingdom.
It said the vaccine was nearly as effective in protecting against the more highly contagious variant first discovered in the UK. A mid-stage trial of the vaccine in South Africa showed 60 per cent effectiveness among people who did not have HIV.
Both the Novavax and Janssen shots will need to be reviewed by regulators before they can be used. If given the greenlight, the two jabs supplement existing ones made by Pfizer/BioNTech, Moderna and AstraZeneca.
Despite the positive results from the clinical trials, which promise to bring additional doses and choices to the table, African countries will still wait longer than the Western countries to get their first batches.
"We as a continent must recognise vaccines will not be here when we want them," the director of the African Centres for Disease Control and Prevention (Africa CDC), John Nkengasong, said at the annual World Economic Forum's online summit.
The WHO has constantly said that the continent will receive the vaccines “in the next coming weeks” but declined to give a tentative date as to when they will arrive.
As of Thursday, statistics from Our World in Data indicated that around 86.8 million doses had been administered across the world, enough to cover 48.4million people (or just 0.62 per cent) globally.
“The European Medicines Agency today issued conditional manufacturing authorisation for the AstraZeneca vaccine. In the next two weeks we should also have an emergency use listing permit for our manufacturing sites in India and South Korea,” Dr Soumya Swaminathan, the chief scientist at the WHO, said during a virtual press conference Friday.
Even with the money, experts now estimate that supply chain issues, vaccine hoarding by wealthy countries and looming global vaccine battles further push the timelines for low- and middle-income countries’ access to six to eight months behind richer nations.
The Duke global health innovation centre's current models predict that there will not be enough vaccines to cover the world's population until 2023 or 2024.
For instance, one of the key vaccines many countries have been banking on, AstraZeneca, is already caught up in a brawl with the European Union (EU) over delays.
On Monday, EU officials said they had been told by AstraZeneca that production problems meant the company would supply "considerably fewer" doses in the coming weeks than had been agreed. As a result, the EU threatened to block exports of the vaccines to countries outside the bloc without prior authorisation, until doses needed for Europe are provided.
WHO Director-General, Tedros Adhanom Ghebreyesus, last week said plans to start deliveries in February to many of the world’s poorer countries are at risk and that he feared a number of high-income countries may backtrack on their promises of equitable distribution.
“I need to be blunt: the world is on the brink of a catastrophic moral failure and the price of this failure will be paid with lives and livelihoods in the world’s poorest countries,” he said.
Meanwhile, with more than 175,000 new cases and 6,200 deaths reported in the last week, Africa is scrambling to obtain supplies for its 1.3 billion people.
John Nkengasong, director of the AU’s disease control and prevention body, Thursday said that in addition to 270 million doses previously secured, the bloc would get 400 million AstraZeneca/Oxford University shots from the Serum Institute of India (SII).
As it stands, the AstraZeneca vaccine is the cheapest option, going for Sh300 per dose, and the easiest to store and distribute.
Separate from the AU’s efforts, Africa is to receive about 600 million vaccine doses this year via the Covax facility co-led by the WHO.
According to a draft briefing on the plan prepared by the African Export-Import Bank (Afreximbank) and published by Reuters, countries will pay between Sh300 ($3) and Sh1,000 ($10) per person to access the AU shots.
Serum Institute will provide 100 million doses of AstraZeneca's vaccine at $3 each, similar to the price for India, Pfizer will provide 50 million doses of its two-shot vaccine at $6.75 each, while J&J will provide 120 million doses of its single-shot vaccine at $10 each, the document showed.
