Clinical Research Directory

Risk Assessment of Community Spread of Multiple Endemic Infectious Diseases in a One Health Perspective

RACSMEI addresses the high burden of infectious diseases in low- and middle-income countries, including Cambodia, where limited surveillance and laboratory capacity often obscure etiologies and transmission dynamics. This knowledge gap hinders the design of effective prevention and control strategies. RACSMEI will improve understanding across multiple pathogens using a multidisciplinary One Health approach. We will answer key questions on burden, ecology, transmission and population immune status to inform targeted and culturally appropriate interventions. The project combines a nationally representative One Health survey, social-science methods, and multiplex, diverse diagnostics to efficiently test for 57 priority pathogens, including zoonotic and vector-borne agents, vaccine-preventable and elimination-targeted diseases, enteric, respiratory, and environmentally transmitted pathogens and selected neglected tropical diseases and parasites relevant to Cambodia. Mathematical modelling will reconstruct and forecast transmission dynamics and assess the potential impact of future public-health strategies. By integrating intersectoral data and innovative methods, RACSMEI will generate actionable evidence for public-health authorities, support precision One Health interventions, and help reduce disease burden in affected communities. The project also aims to ensure the transferability of methods and insights to other countries facing similar challenges.

the Five-year Antibody Persistence After Immunization With IPV, MMR and HepA-L Vaccines

This study evaluated the antibody persistence of Chinese children five years after they received four doses of sIPV, two doses of MMR vaccine and one dose of HepA-L vaccine.

Long-term Immunogenicity of L-HAV Vaccine Among Healthy Thai Children and Adolescents

Hepatitis A virus (HAV) remains a common infection among Thai children. Two types of HAV vaccines are available in Thailand: an inactivated vaccine (I-HAV, administered in two doses 6 months apart) and a live-attenuated vaccine (L-HAV, administered as a single dose). However, neither vaccine is currently included in Thailand's Expanded Programme on Immunization (EPI). In 2024, a randomized, active-controlled, open-label, non-inferiority trial was conducted to compare the immunogenicity and safety of the two-dose I-HAV with the single-dose L-HAV in healthy Thai children and adolescents aged 18 months to 18 years. This study aims to evaluate the long-term seropositive rate and immunogenicity of anti-HAV antibodies in this population following a single dose of L-HAV.

Immunogenicity and Safety of I-HAV in Healthy Thai Children and Adolescents Lacking Protective Antibody After L-HAV

Hepatitis A virus (HAV) remains a common infection in Thai children. Two HAV vaccines are available: inactivated vaccine (I-HAV, 2 doses) and live-attenuated vaccine (L-HAV, single dose), but neither is included in Thailand's national immunization program. Our previous randomized, active-controlled, open-label, non-inferiority trial trial found that some participants remained seronegative after one L-HAV dose (anti-HAV IgG \<1 S/CO) (preliminary data). This study aims to evaluate the immunogenicity and safety of an additional dose of I-HAV in healthy Thai children and adolescents who did not develop protective antibody levels after a single dose of L-HAV.

Immunity With Acute Hepatits A

Hepatitis A Virus (HAV) is a public health concern in Egypt, especially among children. Historically highly endemic, recent studies suggest a changing epidemiology. While improved socioeconomic conditions have reduced its spread, HAV remains prevalent, with over 50% of Egyptians exposed by age 15. Infection is often asymptomatic or mild in children but can be more severe with age. Prevention relies on improved sanitation and hygiene, with vaccin and recov

Immunogenicity and Safety of Hepatitis A Among People Aged 18-50 Years Old

This study is conducted among people aged 18-50 in Dandong City, an area with a high incidence of hepatitis A in recent years. 1000 qualified pariticipants with signed informed consent will be screened for anti-HAV antibodies by collecting blood sample of 3ml. One dose of hepatitis A vaccine will be administrated to all the pariticipants. Negative anti-HAV antibodies-negative subjects will recieve the second dose of hepatitis A vaccination, and 400 of them will be randomly selected and assigned to 4 groups with different interval of vaccination(6 month, 18 months, 36 months and 60 months). Blood samples will be collected before vaccination of each dose and on 28 days after each dose of vaccination to anti-HAV antibody test. Safety data will be collected within 28 days after each vaccination with a smartphone mini-program.

Phase IV Study of Concomitant Administration of the sIPV and HepA

This study is a randomized, open-labeled phase IV clinical trial to evaluate the immunogenicity and safety of concomitant administration of sIPV and HepA-L or HepA-I in children aged 18 months. The primary immunogenicity endpoints in all groups are the seroconversion rates of type I, II, and III anti-poliovirus neutralizing antibodies and the seroconversion rate of anti-hepatitis A virus antibodies 30 days after the final administration. The secondary immunogenicity endpoints are (1) the GMT/GMC of type I, II, and III anti-poliovirus neutralizing antibodies as well as the anti-hepatitis A virus antibodies 30 days after the final administration; (2) the seropositive rates of the anti-hepatitis A virus antibodies 30 days after the final administration; (3) the GMFI of type I, II, and III anti-poliovirus neutralizing antibodies as well as the anti-hepatitis A virus antibodies 30 days after the final administration. The secondary safety endpoints are the incidence of adverse events (AEs) within 30 minutes after each injection, the incidence of solicited local and systematic AEs in the period of solicitation after each injection, the incidence of unsolicited AEs in 30 days after each injection, the incidence of AEs in 30 days after each injection, and the incidence of serious adverse events in 6 months after administrations.