Long-Term Protection of Vi Antibodies Induced by Vi-DT Conjugate Vaccines (Bio TCV) in Indonesian Population Compared to PQed TCV

Typhoid fever is a serious systemic infection caused by the enteric pathogen Salmonella enterica serovar typhi. S typhi is spread by the fecal-oral route. Although largely an endemic disease, S. typhi has epidemic potential. Data mainly from Asia, Africa and Latin America show that typhoid fever continues to be a public health problem in many developing countries, with school-age children (aged 5-15 years) disproportionately affected. In some endemic areas, children aged < 5 years show incidence rates similar to, or exceeding those, of school age children. WHO conservatively estimates the annual global incidence of typhoid fever at 21 million cases, of which 1-4% ends fatally. An estimated 90% of these deaths occur in Asia. Increasing multidrug resistance of S. typhi reduces the effective treatment options, increases treatment costs and results in higher rates of serious complications and deaths.

This research aims to determine the long-term immune response after administration of one dose of Bio TCV and PQed TCV vaccines in the population in Indonesia. Research participants will be taken from research participants who complete the Bio TCV (Typhoid 0319) Phase III clinical trial research included in the Main Study Group I. During the research, participants will make one (1) research visit to the health center for examination and blood sampling. After 5 years of being given the Typhoid vaccine, participants will be contacted by telephone to be given information about the research that will be conducted on you/your child. The research team will ask questions about the willingness to participate in the research. If they agree, a visit will be scheduled to the research site. This research is conducted by the Department of Pediatrics, Cipto Mangunkusumo Hospital, Jakarta, Dr. Soetomo Hospital, Surabaya and PT Bio Farma.