Britain to pilot using smaller doses of monkeypox vaccine
Published: Aug 23, 2022 08:53 PM
Britain is following the US and Europe in making the most of limited supply of the monkeypox vaccine by administering smaller doses of the shot, health officials said on Monday.

Three National Health Service sites are set to begin a pilot testing of the so-called fractional dosing approach, which involves 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 (intradermal injection).

The Bavarian Nordic vaccine - called Jynneos, Imvanex and Imvamune, depending on geography - was designed to be injected into a layer of fat beneath the skin, known as a subcutaneous injection.

The approach is backed by a study involving about 500 adults, which compared the performance of the vaccine given either intradermally or subcutaneously, as two doses given about a month apart.

Those who received the intradermal injection received one-fifth of the subcutaneous dose, but produced similar levels of antibodies as those who received the original subcutaneous dose, according to a study published in 2015.

In recent weeks, both US and EU regulators have backed the fractional dosing approach to stretch out scarce supplies. 

More than 40,000 confirmed cases of monkeypox - including a handful of deaths - in more than 80 countries and regions where the virus is not endemic have been reported since early May. Up to August 15, there were nearly 3,100 confirmed cases in the UK.

The UK has ordered 150,000 doses of the vaccine, a UK Health Security Agency (UKHSA) spokesperson told Reuters earlier in August.

About 50,000 doses have already arrived, while the rest are expected in September.

Due to the limited vaccine stock, the ­post-exposure offer of vaccination is now being reserved for those close contacts who are at highest risk of severe illness, the UKHSA added on Monday.