China’s Enterovirus 71 Vaccine Reported Very Protective Against Hand-Foot-and-Mouth Disease

A recent phase 4b clinical study in Hubei Province, China, reported very positive results regarding an existing vaccine against Enterovirus A71 (EV-A71).

This is important news since EV-A71 has emerged as a major concern among pediatric infectious diseases during the past 20 years.

EV-A71 is a major pathogen causing hand-foot-and-mouth disease (HFMD), particularly in the Asia-Pacific region. As an example, an EV-A71 epidemic occurred in Taiwan in 1998, which caused 405 severe cases and 78 fatalities.

The target population for the EV71-infected HFMD cases in this study was children between the ages of 6 to 71 months.  

Given this younger population, it is necessary to conduct a postmarketing phase 4b trial for long-term observation to evaluate the KMB-17 vaccine’s distinctive effectiveness and to identify potential safety issues.

This open-label and controlled post-marketing study’s results were published in Clinical Infectious Diseases on November 11, 2019.

This study found the inactivated KMB-17 vaccine was shown to have an overall vaccine effectiveness of 89.7 percent effective against HFMD, from 40,724 children evaluated.

And, the KMB-17 vaccine produced a 4.58 percent adverse event rate, with the passive surveillance showed a 0.31 percent rate of common minor reactions.

This is reassuring news since EV71 is a major pathogen causing hand-foot-and-mouth disease. An infection that occasionally leads to severe diseases, with central nervous system (CNS) damage.

A stage-based management approach was developed for the treatment of EV-A71 infection in 2000, and it lowered the case-fatality rate of severe EV-A71 cases, but long-term sequelae are very concerning, especially in young children, reported an August 2019 study.

Neurodevelopment and cognitive function may be affected by viral encephalitis or by bacterial meningitis. The fact that the survival rate of children with EV-A71 CNS infections has improved after stage-based management, shows that it is important to monitor neurological and functional outcomes.

Regarding hand, foot, and mouth disease, it is a contagious illness caused by different viruses. HFMD is usually not serious, and most people recover in 7 to 10 days, without medical treatment, says the US Centers for Disease Control and Prevention (CDC).

Rarely, an infected person can develop viral meningitis and may need to be hospitalized for a few days. Other even more rare complications can include paralysis or encephalitis, which can be fatal.

In the United States it is more common for people to get HFMD during summer and fall, says the CDC. 

There is no specific treatment for HFMD, and it is important for people with HFMD to drink enough fluids to prevent dehydration.

HFMD is often confused with foot-and-mouth disease (also called hoof-and-mouth disease), which affects cattle, sheep, and swine. Humans do not get the animal disease, and animals do not get the human disease, said the CDC during July 2019. 

The KMB-17 vaccine previously completed phase I, II and III clinical trials and was licensed in China in December 2015. 

This vaccine is currently not licensed in the USA.

This phase 4b study sponsors and collaborators were the Chinese Academy of Medical Sciences and the Hubei Provincial Center for Disease Control and Prevention (HPCDC). The Principal Investigator was Xuhua Guan, M.S., with HPCDC.

Hand-Foot-and-Mouth vaccine news published by Precision Vaccinations