WHO adds LC16m8 mpox vaccine to list for emergency use

The World Health Organization (WHO) approved Emergency Use List (EUL) for LC16m8 mpox vaccinemaking it the second mpox vaccine to be endorsed by WHO after the Director-General declared the mpox Public Health Emergency of International Concern (PHEIC) on 14 August 2024.

This decision is expected to facilitate increased and timely access to vaccines in communities where measles outbreaks are on the rise. In 2024, cases were reported in 80 countries, including 19 countries in Africa, based on data as of October 31, 2024. The Democratic Republic of Congo, the hardest-hit country, has recorded the vast majority of suspected cases – over 39,000 – as well as more than 1,000 deaths.

Today's move is particularly important as the Government of Japan has announced that it will donate 3.05 million doses of the LC16m8 vaccine, along with specialized vaccination needles, to the Democratic Republic of the Congo. This is the largest donation package announced to date in response to the current mpox emergency.

LC16m8 is a vaccine developed and manufactured by KM Biologics in Japan. The EUL Vaccines Technical Advisory Group (TAG) met to discuss the outcome of the LC16m8 vaccine review, including product and program suitability assessments. LABEL recommended the vaccine for use in persons older than one year as a single-dose vaccine, using the technique of multiple injections using a bifurcated needle.

“WHO's listing of the LC16m8 measles vaccine for emergency use marks a significant step in our response to the current crisis situation, providing a new option to protect all populations, including children,” said Dr. Yukiko Nakatani, WHO Assistant Director-General for Access to Medicines and Health Products. “Vaccines are one of the important tools to contain the epidemic as part of a comprehensive response strategy that also includes improved testing and diagnosis, treatment and care, infection prevention control, and engagement and education within affected communities.”

WHO's assessment of the EUL is based on information provided by the manufacturer and review by the Medicines and Medical Devices Agency (PMDA), Japan's regulatory agency for this vaccine. The LC16m8 vaccine has been used in Japan during previous measles outbreaks and has been shown to be safe and effective, including in people with well-controlled HIV.

The WHO Strategic Advisory Group of Experts (SAGE) on Immunization reviewed the available evidence and recommended use of the LC16m8 vaccine in outbreak settings in children and others with a documented high risk of exposure to mpox.

However, minimally replicating vaccines such as LC16m8 should not be used during pregnancy and in immunocompromised individuals. Immunocompromised individuals include those with active cancer, transplant recipients, immunodeficiency, and active treatment with immunosuppressive agents. They also include people living with HIV with a current CD4 cell count <200 cells µl.

The Global Vaccine Safety Advisory Committee reviewed the LC16m8 safety update on September 20, 2024 and recommended that healthcare professionals be provided with training on use of bifurcated needles to prevent injury and adverse effects. In light of changing epidemiology and the emergence of new virus strains, it is still important to collect as much data as possible on the safety and efficacy of vaccines in different contexts.

WHO continues to work closely with manufacturers, global partners and countries to ensure the availability and use of safe and effective life-saving products.

On September 13, 2024, the WHO prequalified the modified Vaccinia Ankara-Bavarian Nordic (MVA-BN) vaccine and on October 8, 2024, expanded its indication to include use in persons aged 12 years and older.

Note to editors:

WHO prequalification (PQ) and Emergency Use Listing (EUL) are mechanisms used to assess the quality, safety and efficacy of medical products, such as vaccines, diagnostics and drugs, and the suitability of products for use in the context of low- and middle-income countries. . Products that receive a PQ or EUL support decision-making for international, regional and national procurement by UN and partner procurement agencies and Member States. The PQ is based on a review of the entire data set on the quality, safety and efficacy of medical products, including a risk management plan and programmatic suitability. EUL is a risk-benefit assessment to address urgent requirements during public health emergencies based on the limited data available where the benefits outweigh the risks.