Authorities consider limiting Monkeypox vaccine dosage

Health officials in Europe are discussing whether to follow a move by the United States to stretch out scarce monkeypox vaccine supplies.

The move comes as the World Health Organisation has called for more data.

There have been 27,800 monkeypox cases – largely among men who have sex with men – and 12 deaths worldwide this year.

Supplies of the key Bavarian Nordic shot, the only vaccine authorised to prevent monkeypox and a key part of the global public health response, are scarce, according to WHO and other government health agencies.

This week the US backed using one vial of the vaccine to administer up to five separate doses – instead of a single dose – by injecting a smaller amount in between layers of the skin. The vaccine was designed to be injected into a layer of fat beneath the skin.

This so-called ‘dose-sparing’ approach has been tried before with other vaccines, including for polio and yellow fever, but evidence is limited on whether it could work for monkeypox.

It is understood that the European Medicines Agency (EMA) will also discuss the possibility of a dose-sparing approach, according to reports.

According to the US Food and Drug Administration, data collected in a 2015 clinical study demonstrated that dose-sparing could work without sacrificing the safety and efficacy of the vaccine.

Meanwhile, some governments in Europe are taking other steps to extend existing supplies. The UK is offering just one shot of the two-dose regimen to people most at risk as a temporary measure to afford at least some protection to a greater number of people.