Typbar TCV Vaccine
- 10 Dec 2019
- 3 min read
Why in News
Hyderabad-based Bharat Biotech has developed a typhoid vaccine (Typbar TCV) which has better efficacy than the previously used vaccinations in preventing typhoid fever.
- Typbar TCV is a type of conjugate vaccine which has already been pre-qualified by the World Health Organisation’s Strategic Advisory Group of Experts on Immunization (WHO-SAGE).
- Currently, two typhoid vaccines viz. Polysaccharide Typhoid Vaccine and Live, Weakened Typhoid Vaccine are used in India. However, their efficacy is lower than the conjugate vaccine as they offer 60-70% protection, unlike the conjugate vaccine which confers nearly 82% protection.
- It is a type of conjugate vaccine. Conjugate vaccines are made using a combination of two different components. In Typbar TCV, an antigen is chemically linked to a carrier protein to create more powerful combined immune response.
- The conjugate vaccine can be given to babies as young as six months, while the other two typhoid vaccines — polysaccharide typhoid vaccine and live, weakened typhoid vaccine cannot be given to children below two years of age.
- Its single dose is effective in preventing typhoid in children aged 9 months to 16 years. It confers protection two-three weeks after the administration.
- Typhoid bacteria can be treated with antibiotics but the microbes have developed resistance against multiple antibiotics.
- Extensively drug-resistant (XDR) typhoid outbreaks have been found in India, Bangladesh, and Pakistan.
- Typbar TCV is the world’s first clinically proven conjugate Typhoid vaccine.
- Bharat Biotech has been supplying the typhoid conjugate vaccine to Pakistan since 2017. Pakistan is also the first country to introduce the typhoid conjugate vaccine as part of its national immunisation programme.
- Typhoid fever is caused by the highly contagious Salmonella Typhi bacteria. The bacteria spread through contaminated food or water.
- Symptoms are prolonged fever, headache, nausea, loss of appetite, and constipation or sometimes diarrhoea.
- These are often non-specific and clinically non-distinguishable from other febrile illnesses.
- Clinical severity varies and severe cases may lead to serious complications or even death.
- According to the WHO, a large proportion of severe typhoid fever cases occur in children aged below two years.