First mpox vaccine candidate begins trials

China's first mpox vaccine candidate has begun Phase I clinical trials, the Shanghai Institute of Biological Products Co said on Tuesday.

Medical experts said the vaccine could play a crucial role in preventing and controlling mpox in China and beyond.

The company, a subsidiary of China National Biotec Group, said trials of the MVA strain mpox attenuated live vaccine are underway at Henan Infectious Diseases Hospital in Zhengzhou, Henan province.

Designed for people age 18 and older at high risk for mpox, the vaccine trials aim to enroll 120 participants in Zhengzhou, including 60 healthy individuals, 30 men who have sex with men and 30 people living with HIV.

The National Medical Products Administration, China's top drug regulator, approved the vaccine for clinical trials in September, making it the country's first mpox vaccine candidate to enter the clinical stage.

In China, vaccine candidates typically undergo three phases of clinical trials before receiving market approval, a process that can take years. However, regulatory authorities have launched accelerated channels to expedite applications for novel drugs and vaccines in urgent demand.

The new vaccine is a replication-deficient vaccine based on a modified vaccinia Ankara (MVA) strain, similar to Jynneos, the world's first mpox vaccine, developed by Danish company Bavarian Nordic.

Preclinical studies showed the vaccine candidate was safe and generated immune protection against the mpox virus in primate models, the company said.

"We will fully cooperate to ensure the smooth progress of the clinical trials and accelerate the follow-up transformation work of the vaccine, striving for marketing soon and contributing to mpox prevention in China and globally," Li Xiuling, general manager of the Shanghai Institute of Biological Products, said at a meeting at the Henan hospital in January.

Mpox is a viral zoonotic disease caused by the mpox virus and spreads through direct contact, respiratory droplets, contaminated items, and mother-to-child and sexual transmissions. Its clinical features resemble smallpox, though with milder symptoms and a lower mortality rate of 1 to 10 percent.

The WHO issued temporary guidelines for mpox vaccinations in August 2022, recommending them for close contacts of mpox patients and high-risk groups, including men who have sex with men, people with multiple sexual partners and healthcare workers at risk of exposure.