Typbar TCV® Typhoid Vaccine
Bharat Biotech International's Typbar TCV® is a vaccine containing a polysaccharide of Salmonella typhi Ty2 conjugated to Tetanus Toxoid. A human challenge study at the University of Oxford demonstrated that the vaccine is safe, 100% immunogenic, and prevents up to 87.1% of infections when using real-life definitions of typhoid fever. Vi Capsular polysaccharide of Salmonella typhi alone elicits B cell responses. In addition, the conjugation of bacterial polysaccharides to a protein carrier provides foreign peptide antigens presented to the immune system, eliciting antigen-specific CD4+ Th cells, referred to as T-dependent antibody responses. A hallmark of T-dependent responses elicited by toxoids is to induce higher-affinity antibodies and long-term immune memory.
A human challenge study at the University of Oxford demonstrated that the vaccine is safe, immunogenic, and prevents up to 87.1% of infections using real-life definitions of typhoid fever. A mathematical modeling study supported by Gavi published on February 3, 2022 - Estimating the effect of vaccination on antimicrobial-resistant typhoid fever in 73 countries - found the introduction of routine immunization with TCV at age nine months with a catch-up campaign up to age 15 years was predicted to avert 46–74% of all typhoid fever cases.
The peer-reviewed journal The Lancet published an early-release (September 1, 2022) phase 3 study funded by the Gates Foundation - Safety and immunogenicity of a typhoid conjugate vaccine among children aged nine months to 12 years in Malawi: a nested substudy of a double-blind, randomized controlled trial. This study provides evidence of TCV vaccination safety, tolerability, and immunogenicity up to 730–1,035 days in Malawian children aged nine months to 12 years. On January 25, 2024, updated results from the phase 3 clinical study were published today in The Lancet. The research team enrolled more than 28,000 healthy children in Malawi. It randomly assigned about half the group to receive the TCV and the other half to receive a meningococcal capsular group A conjugate (MenA) control vaccine. During the more than four years of follow-up, 24 children in the TCV group and 110 in the MenA group developed typhoid fever, which was confirmed via blood culture. That resulted in an efficacy of 78.3 percent in the TCV group, with one case of Typhoid prevented for every 163 children vaccinated. TCV was effective in all age groups, and over the study period – which ended in 2022 – vaccine efficacy remained strong, decreasing by only 1.3 percent per year.
Typbar TCV is the only U.S. FDA-approved vaccine for children less than two years of age. Typhoid fever caused by multidrug-resistant H58 Salmonella Typhi is an increasing public health threat in sub-Saharan Africa. In addition, Typbar TCV has been recommended by the experts at the WHO-Strategic Advisory Group for routine immunizations and is WHO-prequalified.
Bharat Biotech is a pioneering biotechnology company known for its world-class R&D and manufacturing capabilities. The Bill & Melinda Gates Foundation funds TyVAC.
Typbar TCV Indication
Vaccination can help prevent typhoid fever, an acute enteric disease caused by Salmonella enterica serovar Typhi (S Typhi). S Typhi is a rod-shaped, gram-negative, anaerobic bacterium expressing surface polysaccharide capsule (Vi antigen), a critical virulence determinant. The UU.S.CDC recommends vaccination for people traveling to places with common typhoid fever, says the UU.S.CDC. Typhoid fever remains a significant cause of morbidity and mortality in low-income and middle-income countries, says the WHO. Typhoid fever, a systemic febrile illness caused by Salmonella enterica serovar Typhi, is responsible for more than 9 million infections and more than 110,000 deaths globally annually. The highest disease burden was observed among children.
The Typbar TCV vaccine is indicated as a preventative vaccine against Typhoid, which Salmonella Typhi and Paratyphi cause. If it is not treated, it can kill up to 30% of people who get it. Some people who get Typhoid become "carriers," who can spread the disease to others. Curbing typhoid transmission can also prevent resistant plasmid transfer to other bacterial pathogens. Our results can help inform country-level decision-making and prioritize TCV introduction in countries with a high incidence of antimicrobial-resistant typhoid fever.
Typbar TCV Dosage
The WHO recently recommended that routine childhood immunization programs include Typbar TCV as a single intramuscular dose for primary vaccination of infants and children from 6 months of age. It is also recommended for adults ≤45 years of age and in catch-up campaigns in typhoid-endemic regions in children ≤15 years of age.
According to the U.S., two typhoid fever vaccines are available in the USA. However, typhoid vaccines are not 100% effective. Oral vaccine: Can be given to people at least six years old. It consists of four pills taken every other day and should be finished at least one week before travel. An injectable vaccine that can be given to people at least two years old should be given at least two weeks before travel.
The Typbar-TCV is a WHO-prequalified tetanus-toxoid conjugated Vi-TCV containing 25 μg of Vi polysaccharide per 0.5-ml dose.
Typbar TCV News
January 25, 2024 - "The newly published study supports the long-lasting impacts of a single shot of TCV, even in the youngest children, and offers hope of preventing typhoid in the most vulnerable children," said Kathleen Neuzil, MD, MPH.
August 10, 2022 - A new study finds the Typbar TCV® vaccine provides immunity for up to three years in children as young as nine months old and is safe and well tolerated. INotably, the vaccine can be given to nine-month-old infants at the same time as routine measles-rubella vaccinations without reducing the immune response to either vaccine.
June 21, 2022 - The Lancet Microbe reported while multi-drug resistance to first-line antibiotics has generally declined in South Asia, strains resistant to macrolides and quinolones – two of the most important antibiotics for human health – have risen sharply and spread frequently to other countries.
April 7, 2022 - With support from Gavi, the Vaccine Alliance, WHO, UNICEF, and other partners, the Government of Nepal today launched a new vaccine campaign introducing Typhoid Conjugate Vaccine into the routine immunization program. The campaign aims to reach 95% coverage of nearly 7.5 million children.
February 3, 2022 - A meta-analysis of disease burdens in 73 countries eligible for support from Gavi, Birger, and colleagues has shown that the introduction of routine immunization of children from age nine months with typhoid conjugate vaccines, with a catch-up program up to age 15 years, would avert about 66 million cases and 826,000 deaths caused by typhoid fever over ten years.
November 1, 2021 - The Lancet Global Health published the final results of the Phase 3 clinical trial. These results are from the 2-year follow-up of 20,019 children aged nine months to < 16 years of age. The final results are similar to the interim results. There is no evidence of waning protection over the two years. These results support the WHO recommendations to vaccinate children in endemic typhoid settings.
September 16, 2021 - The New England Journal of Medicine published a study that found a single dose of Typhoid conjugate vaccine is safe and 84 percent effective in protecting against Typhoid in Blantyre, Malawi. An intention-to-treat analysis comparing this incidence with that in the Vi-TCV group yielded a protective efficacy of Vi-TCV of 80.7%. The effectiveness of Vi-TCV was similar in children younger than five years of age and children who were five years of age or older at the time of vaccination, and this efficacy remained consistent throughout the observation period.
August 21, 2021 - Recent data confirmed Bangladesh has one of the highest typhoid burdens in the world. A study conducted in Mirpur, Dhaka, with typhoid conjugate vaccine (TCV), has found that the vaccine prevents 85% of cases among vaccinated children aged nine months to 15 years.
August 9, 2021 - A new study conducted in Mirpur, Dhaka, with typhoid conjugate vaccine (TCV) and published by The Lancet found that the vaccine prevents 85% of cases among vaccinated children aged nine months to 15 years.
July 1, 2021 - UNICEF, Gavi, the Vaccine Alliance, and the WHO have partnered with the Ministry of Health and Child Care to launch a new vaccine campaign introducing TCV into the routine immunization schedule across Zimbabwe, which is the third country in the world to introduce the typhoid conjugate vaccine into the regular immunization program showing Zimbabwe's leadership in immunization in the Africa region and globally. In 2019, Pakistan introduced the vaccine into routine immunization schedules, and Liberia followed suit in April 2021.
April 5, 2021 - Liberia became the first country in Africa to introduce the typhoid conjugate vaccine (TCV) with a weeklong campaign to reach more than 1.9 million children aged nine months to younger than 15 years old with TCV. After the campaign concludes, TCV will become a routine immunization for all children at nine months old.
February 12, 2021 - U.S. reports extensive drug-resistant salmonella typhi infections among residents without international travel.
February 1, 2021 - The next step: Lifesaving typhoid conjugate vaccines reach Punjab province, Pakistan. For the next two weeks, vaccination teams will be in Islamabad and 12 districts of Punjab province to vaccinate nearly 12.7 million children between 9 months to 15 years against Typhoid. Keeping children protected against typhoid diseases, we help keep children in school and spare families the economic hardship of typhoid diagnosis and treatment.
January 4, 2021- How a scientist's return kickstarted Bharat Biotech's journey. The company also developed and launched Typbar TCV, the world's first clinically proven and WHO-prequalified TCV, which can be administered to even a six-month-old.
September 30, 2020 - Travel Alert: EExtensive drug-resistant typhoid fever in Pakistan. The CDC recommends that all travelers (even short-term travelers) to South Asia, including Pakistan, be vaccinated against typhoid fever before travel.
November 18, 2019 - Pakistan became the first to introduce TCV into the routine immunization system, and the world watched. Nearly 10 million children were vaccinated in just three weeks in Sindh province, protecting them against a potentially deadly disease and sparing their families the economic hardship that so often comes with a case of Typhoid.
January 3, 2018 - Typbar TCV from Bharat Biotech, World's First Typhoid Conjugate Vaccine Prequalified by WHO. This enables the procurement and supply of this lifesaving vaccine to UNICEF, Pan-American Health Organization, and GAVI-supported countries. In addition, Typbar TCV® has been evaluated in Human Challenge Studies at Oxford University, and typhoid conjugate vaccines have been recommended by WHO's Strategic Advisory Group of Experts on Immunization.
Typbar TCV Typhoid Vaccine Clinical Trials
Clinical Trial NCT03299426: Among Malawian children nine months to 12 years of age, administration of Vi-TCV resulted in a lower incidence of blood culture-confirmed typhoid fever than the MenA vaccine. Last updated on 2023-02-08.
Clinical Trial NCT03933098: Immune Non-inferiority and Safety of a Vi-DT Typhoid Conjugate Vaccine. This is a multicenter, observer-blinded, randomized, active-controlled, Phase 3 study in healthy Nepalese aged six months to 45 years at the first vaccine dose.
Clinical Trial NCT03600025: Cellular Immune Responses in Typhoid Fever Patients and Vaccinees (Recruiting). This Phase 1 clinical trial aims to understand further the role of mucosal-associated invariant T cell (MAIT) and natural killer (NN.K. cell responses in typhoid fever or following vaccination.