[GENEVA] The WHO is poised to activate its last-resort alarm for the growing mpox outbreak in central Africa by declaring it a Public Health Emergency of International Concern (PHEIC) – with the committee responsible for the decision meeting on Wednesday.

It would be only the eighth time the WHO has declared a PHEIC, and the previous declaration in May 2022 was also because of mpox, though that outbreak was caused by the less lethal clade 2 variant.

This time, concern centres around the deadlier clade 1b, which can be transmitted directly between humans through sexual contact.

At the same time – and for the first time ever – the Africa Centres for Disease Control and Prevention (Africa CDC) plans to declare a Public Health Emergency of Continental Security, under which African Union countries will coordinate their response to the epidemic.

Both emergency listings are aimed at slowing the spread of a virus that is threatening to cause the next pandemic.

A PHEIC could allow African countries to start buying mpox vaccine without a time-consuming national licensing process, and in greater quantities than donated stocks.

However, so far, bureaucratic delays mean even 50,000 doses the US donated to DRC months ago will not arrive for at least two more months. Once they do, transport, reliable refrigeration, trained health workers, monitoring, syringes and other tools must be in place before the vaccines reach people.

Jean Kaseya, head of Africa CDC, said last week that the African emergency declaration will allow African countries to negotiate jointly for existing and novel mpox vaccines, including an mRNA vaccine due to be manufactured in Rwanda next year by German drug firm BioNtech, which pioneered Covid mRNA vaccines.

WHO director Tedros Ghebreyesus said he decided to convene an expert committee to decide on a PHEIC – it will meet, online, on Wednesday (14 August) – because of “the spread of mpox outside DRC, and the potential for further international spread within and outside Africa”.

Clade 1b shows signs of being in the early phases of a major epidemic.

“It’s climbing disproportionately faster than cases elsewhere in DRC,” which are thought to all be of the older kind, now called Clade 1a, Rosamund Lewis, emergency manager for mpox at the WHO, told SciDev.Net.

Clade 1a, which is not sexually transmitted, is also soaring. However, as animals are involved in the transmission, it doesn’t carry the same pandemic potential as clade 1b, which can be indefinitely maintained by spread among humans alone.

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The answer lies with the two mpox vaccines now commercially available, one made by Bavarian Nordic in Denmark, the other by KM Biologics in Japan. These can contain the virus if people who might otherwise catch and spread it are immunised.

In July, the emerging infectious diseases foundation CEPI announced trials in the DRC to see if vaccinating people already exposed to mpox stops them getting sick and spreading it.

However, vaccines cannot be purchased at the needed scale by African countries without a WHO emergency designation. Last week in Geneva, Tedros said “I have triggered the process for Emergency Use Listing of both vaccines.”

But it may not be available very soon. Putting Emergency Use Listing in place will take yet more time. A WHO technical committee first approves listing the vaccines – or not. Then companies make offers, and countries negotiate prices and import approvals.

And DRC alone estimates that it needs 10 million doses, not only to contain the potentially pandemic Clade 1b, but to protect the country’s children from 1a. Virus for the Bavarian Nordic vaccine is grown in hen’s eggs. It isn’t clear how fast how many doses can be made.

This article was produced by SciDev.Net’s Global desk.