The results of the phase 3 clinical trial demonstrate that the overall protective efficacy of the first hand, foot, and mouth disease vaccine in Vietnam against the EV71 virus is 96.8%.
According to Dr. Nguyễn Trọng Toàn, Deputy Director of the Clinical Trial Center at the Pasteur Institute in Ho Chi Minh City, the first hand, foot, and mouth disease vaccine has successfully completed phase 3 trials. The Ethics Committee recognized that the vaccine effectively protects children against hand, foot, and mouth disease caused by EV71 at any severity level, achieving an efficacy of 96.8%.
This result was published in the prestigious medical journal The Lancet in 2022. The vaccine is currently awaiting approval from the Ministry of Health.
Rash on the foot of a child with hand, foot, and mouth disease. (Photo: Đinh Hằng/TTXVN).
According to Dr. Nguyễn Trọng Toàn, the hand, foot, and mouth disease vaccine was initially developed by the National Health Research Institute (NHRI) in Taiwan, China, and was further transferred for continued development and clinical trial phases.
In 2010, NHRI conducted phase 1 vaccine trials with 60 healthy volunteers. The results showed that 90% of the vaccine recipients had antibody levels capable of combating the virus, increasing fourfold after vaccination.
From 2014 to 2017, the vaccine underwent phase 2 clinical trials involving 365 volunteers aged between 2 months and 12 months.
Between 2019 and 2021, phase 3 clinical trials were conducted on 3,049 children aged from 2 months to 6 years in Vietnam and Taiwan (China), with 80% of the children being from Vietnam.
In Vietnam, children from six districts in the two provinces of Tiền Giang and Đồng Tháp were selected for the clinical trials due to the high incidence of hand, foot, and mouth disease in the southern region.
Dr. Nguyễn Trọng Toàn mentioned that the phase 3 clinical trials in Vietnam faced numerous challenges due to the impact of Covid-19, as most children stayed home, attended school less frequently, and the disease incidence decreased. Consequently, the research duration had to be extended beyond the initial plan.
The results of the phase 3 clinical trials indicate that the overall protective efficacy of the vaccine against the EV71 virus is 96.8%, with no cases of hand, foot, and mouth disease reported among the vaccinated group during the study period.
The researchers did not observe any anaphylactic shock following vaccination. About 30% of adverse reactions were commonly reported after vaccination, such as swelling, pain, and redness at the injection site, similar to other vaccines. Systemic reactions accounted for 42.6%, primarily mild to moderate, and these reactions resolved within 1-3 days.
Based on the efficacy assessment and the clinical trial process, the manufacturer has submitted documentation to the Ministry of Health for approval.
“If approved, this will be the first hand, foot, and mouth disease vaccine in Vietnam, effective in helping children combat the EV71 virus (Enterovirus 71) – the most dangerous strain causing severe hand, foot, and mouth disease with a high risk of mortality,” Dr. Nguyễn Trọng Toàn stated.
The Pasteur Institute in Ho Chi Minh City is collaborating on a phase 3 clinical trial of another EV71 hand, foot, and mouth disease vaccine, with results expected by 2025.
According to Dr. Nguyễn Trọng Toàn, besides dengue fever, hand, foot, and mouth disease is an infectious disease that causes serious consequences for children’s health. For infectious diseases, vaccines are always the most effective and fundamental measure. Therefore, the early availability of a hand, foot, and mouth disease vaccine is significant in controlling the disease and reducing the burden of illness caused by it.
