Typhoid continues to pose a significant public health threat, particularly in areas where water, sanitation, and hygiene infrastructure is a challenge in sub-Saharan Africa and Asia. The latest estimates from the Global Burden of Disease study indicate there are more than 7 million cases and more than 93,000 deaths due to typhoid each year. This burden is most concentrated among children younger than 15 years old.
Thankfully, typhoid is a vaccine-preventable disease. There are currently four typhoid conjugate vaccines (TCVs) on the global market, and two are eligible for support from Gavi, the Vaccine Alliance for endemic countries. TCVs are safe and highly effective at preventing typhoid, and vaccination is a critical part of the strategy to prevent and control the disease. Additional TCV products not only support increased access to safe and effective vaccines but also helps to ensure a stable vaccine supply and market.
Pivotal results from a Phase 3 study on a new TCV
EuTYPH-C Inj.® Multi-dose is a TCV manufactured by EuBiologics Co., LTD, and is one of several additional TCVs in development that could help to diversify the TCV market. Previous studies conducted in the Philippines found EuTYPH-C to be safe and to generate a strong immune response.
PATH led a Phase 3 study, in partnership with EuBiologics and the study sites in Kenya and Senegal, to assess the safety and non-inferiority of EuTYPH-C Inj. Multi-dose compared to a World Health Organization (WHO)-prequalified product, Typbar TCV, in adults, children, and infants. Results, recently published in The Lancet Global Health, showed that EuTYPH-C Inj. Multi-dose was safe and immunogenic in typhoid-endemic populations in sub-Saharan Africa.
Safety was comparable across all groups, with no serious adverse events related to vaccination reported. Immune responses demonstrated that EuTYPH-C Inj. Multi-dose was non-inferior to Typbar TCV. At 28-days post-vaccination, seroconversion rates (a measure of the body’s immune response) were 100% for the single-dose presentation of EuTYPH-C Inj. Multi-dose, 99.6% for the multi-dose presentation of EuTYPH-C Inj. Multi-dose, and 98% for Typbar TCV groups. Seroconversion rates remained high at 6 months post-vaccination.
“The strong safety profile and immunogenicity results for EuTYPH-C Inj. Multi-dose demonstrate the promise of this vaccine in preventing typhoid in endemic countries,” says Patricia Njuguna, Senior Medical Officer and project lead of the study from PATH.
The study also assessed co-administration of EuTYPH-C Inj. Multi-dose with measles-rubella and yellow fever vaccines at 9-12 months of age. Results showed that co-administration did not interfere with immune responses to the different pathogens.
These results are the pivotal data to support WHO prequalification. WHO prequalification is a designation that ensures a vaccine meets strict international quality, safety, and efficacy standards and that allows it to be procured by United Nations agencies and Gavi.
More options, stronger market
The development of new TCVs can foster innovation, promote competition, and increase cost-effectiveness within the market. Additionally, diversification of suppliers can increase the availability of TCVs to meet demand and reduce the risk of supply disruptions. There has been high demand for TCVs in Gavi-eligible countries where typhoid is endemic.
“To date, seven Gavi-eligible countries have introduced TCV, with several more in various stages of the planning and introduction process,” says Dr. Emmanuel Mugisha, Global Director for Vaccine Implementation and Director of TyVAC at PATH, a consortium that aims to accelerate the introduction of TCVs in typhoid-endemic countries.
“The potential for an additional product will help ensure a stable vaccine supply for countries interested in introducing TCV as part of their typhoid prevention and control plans.”
“The potential for an additional product will help ensure a stable vaccine supply for countries interested in introducing TCV as part of their typhoid prevention and control plans.”— Dr. Emmanuel Mugisha, Global Director for Vaccine Implementation, PATH
EuBiologics has submitted the data from this Phase 3 study to support its application for WHO prequalification of EuTYPH-C Inj. Multi-dose. Should EuTYPH-C Inj. Multi-dose be prequalified, it would increase the available supply for countries interested in introducing TCV.
Ultimately, multiple TCV products will improve access and availability of these lifesaving prevention tools for the countries that need them most, saving more lives, and keeping children protected against typhoid.
