Bavarian Nordic’s monkeypox vaccine Jynneos has been granted an emergency use authorisation (EUA) by the US Food and Drug Administration (FDA) for an alternate administration mode.

The US health agency indicated the vaccine for intradermal injection, in people aged 18 years and above, who are at elevated risk for monkeypox infection.

Jynneos is a liquid-frozen non-replicating vaccine against both smallpox and monkeypox.

It uses a live attenuated vaccinia virus, called Modified Vaccinia Ankara, which is closely related to, but less harmful than the variola virus.

In September 2019, the Danish biotechnology company secured FDA approval for Jynneos for subcutaneous administration in the same population.

The current authorisation is said to increase the availability of vaccine doses by five-fold, as intradermal administration uses the volume of the dose to provide the same protection.

Furthermore, the EUA also allows administration of Jynneos in people aged below 18 years, who are at high risk of monkeypox infection but as a subcutaneous injection.

FDA commissioner said Robert Califf said: “In recent weeks the monkeypox virus has continued to spread at a rate that has made it clear our current vaccine supply will not meet the current demand.

“The FDA quickly explored other scientifically appropriate options to facilitate access to the vaccine for all impacted individuals.

“By increasing the number of available doses, more individuals who want to be vaccinated against monkeypox will now have the opportunity to do so.”

The FDA EUA follows the US and the World Health Organization (WHO) declaring monkeypox as a public health emergency, to boost the response against the outbreak.

In April 2020, Bavarian Nordic received a new order from the US Biomedical Advanced Research and Development Authority (BARDA), for the manufacturing and supply of 1.4 million doses of Jynneos, worth $202m.

The order expands the existing option to manufacture 13 million freeze-dried doses.

In June 2022, BARDA placed an order for additional 500,000 doses of liquid-frozen Jynneos, bringing the total vaccine supply to the US, to nearly two million doses.