Typhoid Conjugate Vaccines Needed in Endemic Countries

An early release study published in The Lancet Global Health (April 2024) has revealed that sub-Saharan African countries are experiencing a significant burden of typhoid fever.

Combined with the threat of typhoid strains resistant to antibiotic treatment, this necessitates more robust prevention strategies.

These researchers wrote that such strategies should include using and implementing typhoid conjugate vaccines (TCVs) in endemic settings and improving access to safe water, sanitation, and hygiene.

Currently, the World Health Organization (WHO) has prequalified two TCVs that are effective with children.

In February 2024, IVI and SK bioscience announced that a third TCV, SKYTyphoid™, also achieved a WHO qualification, paving the way for public procurement and increasing the global supply.

Dr. Birkneh Tilahun Tadesse, Associate Director General at IVI and Head of the Real-World Evidence Department, explained in a press release on March 12, 2024, “Through these vaccine effectiveness studies, we aim to show the full public health value of TCV in settings that are directly impacted by a high burden of typhoid fever.”

He adds, “Our final objective, of course, is to eliminate typhoid or to at least reduce the burden to low incidence levels, and that’s what we are attempting in Fiji with an island-wide vaccination campaign.”

There are about 16 million typhoid cases every year, with 140,000 deaths.

However, with generic symptoms such as fever, fatigue, and abdominal pain and the need for blood culture sampling to make a definitive diagnosis, it is difficult for governments to capture the actual burden of typhoid in their countries.

Results from a phase 3 randomized controlled clinical trial published in The Lancet found one dose of the conjugate typhoid vaccine had an estimated efficacy of 78.3% in children ages nine months to 12 years and remained strong over four years.

The U.S. CDC says that in March 2024, vaccination is recommended for people traveling to places where typhoid fever is common. International travelers should visit a healthcare provider or travel vaccine pharmacy to discuss prevention options.