Monkeypox vaccines in development

Chinese drugmaker Sinopharm said on Wednesday that it is developing three potential mRNA vaccines for monkeypox.

The experimental vaccines have been shown in a study to significantly evoke specific antibodies against monkeypox in mice, the company said in a statement.

Compared with attenuated virus vaccines, which are currently available, the new vaccines are believed to be safer and capable of inducing neutralizing antibodies that can prevent infection more quickly, it said.

The research is being led by Yang Xiaoming, chairman of China National Biotech Group, a unit administered by Sinopharm. Research results were published on bioRxiv, a preprint platform on Tuesday.

"The release of these data has filled a gap in monkeypox-specific vaccines based on mRNA technology and helps prepare for the possible spread of monkeypox virus," Sinopharm said.

The company made a key step in vaccine development in late October when it announced having successfully isolated monkeypox virus strains from clinical samples of infected patients.

However, developing new vaccines typically requires years of research and clinical trials before reaching the public.

Animal studies and three phases of human trials are some of the prerequisites for gaining market approval in China.

The mRNA technology behind the vaccine candidates contains genetic instructions for cells to make viral proteins that prime the immune system.

Messenger RNA vaccines attracted considerable interest since the COVID-19 pandemic for their high efficacy and safety despite being a relatively novel tool.

China is also developing homegrown COVID-19 vaccines using mRNA technology, but no injections have gained approval so far.

Because monkeypox and smallpox viruses are highly similar in genome makeup and their antibodies have shown significant cross-protection, it is widely believed that smallpox vaccines can provide some immunity against monkeypox.

Currently, there are three smallpox vaccines available worldwide. One of them, called Jynneos, was approved for monkeypox around 2019 and is being widely deployed to battle monkeypox outbreaks in some regions.

The World Health Organization declared monkeypox a global health emergency on July 23 after a large number of nonendemic countries, including the United States and some in Europe, experienced surging cases from early May.

The mainland reported its first imported monkeypox case on Sept 16 in an incoming passenger arriving in Chongqing in Southwest China.

No other infections have been registered thus far.