A typhoid vaccine has proven to be safe and effective for children, which raises hope of fighting the disease in Sub-Saharan Africa, according to a new study conducted in Malawi.
There are more than 1.2 million typhoid cases and 18 703 deaths per year in the region, the researchers wrote. The World Health Organization (WHO) recommended the typhoid conjugate vaccine in 2018 for use in countries where the disease is endemic.
Clinical trials in Malawi showed that a single dose of typhoid conjugate vaccine (the only one licensed for children as young as six months) prevented typhoid in roughly 84% of 14 069 children aged 9 months to 12 years.
“It is a great result for Malawi and for Africa,” says study co-author Melita Gordon, professor of clinical infection, microbiology and immunology at the University of Liverpool and the Malawi-Liverpool-Wellcome Trust Clinical Research Programme.
“We were the only site chosen for the trial on the continent. The other sites were in Nepal and Bangladesh and the results were completely consistent across the three sites.”
Typhoid is endemic in Malawi, which records 400 to 500 cases per 100 000 every year, according to Queen Dube, chief of health services at Malawi’s Ministry of Health.
While typhoid is treatable, it can impair physical and cognitive development in children, affect school attendance and performance, limit productivity and reduce earning potential.
“The existing vaccine could not be used in very young children. In addition, the first line antibiotics have been found to be ineffective against multi-drug resistant strains,” Prof Gordon said. “With this vaccine, we can now expect a reduced typhoid burden.”
After 18 to 24 months of surveillance, the vaccine was found to be safe, with no serious adverse effects on children. It also worked equally well on pre-school aged children.
Prof Gordon explains that the study encountered challenges such as a few children moving out of the research sites within the study period, and COVID-19 forced them to suspend the study for two months.
“However, we eventually managed a good retention rate due to regular text messaging to parents and the hard work of health surveillance assistants in mobilisation activities,” she added.
The efficacy data of the typhoid conjugate vaccine is the first in Africa, according to Gordon, who hopes that other African countries will follow Malawi’s example in planning to roll out the vaccine.
Source: SciDev.Net
