Hyderabad: Hyderabad-based vaccines manufacturer, Bharat Biotech said that its next generation typhoid vaccine, Typbar-TCV, has demonstrated safety and efficacy in a high risk human challenge clinical study carried out at Oxford University. The clinical studies produced 87 per cent effectiveness as per the trial results published in Lancet.
The study is the first to demonstrate that immunisation with Typbar-TCV is safe, well tolerated and will have significant impact on disease incidence in typhoid endemic areas that introduce the vaccine. This study was conducted in 112 adult volunteers and used a “controlled human infection model”.
According the study, the vaccine is safe, 100 per cent immunogenic, and prevents 55 per cent of typhoid infections in the challenge trial and up to 87 per cent of infections, when using real life definitions of typhoid fever. Efficacy data from this trial will help to fill a long existing knowledge gap regarding Vi-conjugate vaccines.
This data is significant since the currently available vi-ps typhoid vaccines cannot be administered to children below two years, and do not confer long term immunity. Typbar-TCV can be administered to children below two years of age and does confer long term immunity. Protection over a longer term reduces the need for repeat vaccinations.
Commenting on the Lancet published study and Typbar-TCV R&D milestone Dr Krishna Ella, chairman & managing director, Bharat Biotech, said, “The results of this study and the 87 per cent effectiveness success endorse more than 10 years of R&D efforts to develop this vaccine and various clinical trials that have been carried out over the past eight years”, he said. He also mentioned that the company has built dedicated facilities for the manufacture of this vaccine.
“Multidrug-resistant Salmonella typhi has become a major public health problem, as more people are prescribed antibiotics for even common fever in developing nations.”
Dr. Ella stated citing the example of drug resistance against typhoid fever found in Hyderabad city in Pakistan. “We are proud being world-first to pursue a high risk human challenge study and be successful. This paves way for an early realisation of an effective vaccine that can help reduce the typhoid fever disease burden faced by millions of families,” Dr Ella added.
The trial led by professor Andrew Pollard, director, Oxford Vaccine Group, was designed based on human infection models where many of the participants, mostly University students, were to consume a drink containing bacteria. The results of the trial clearly show that the new Typhoid Conjugate vaccine gives superior performance compared to the Typhoid Vi polysaccharide
It is unconscionable that children are still dying by the thousands every year from diseases like typhoid that are completely preventable,” said Anita Zaidi, director of the Enteric and Diarrheal
Diseases team at the Bill & Melinda Gates Foundation.
The Typbar TCV conjugated to tetanus toxoid vaccine human challenge study holds promise particularly in south Asia and sub-Saharan Africa which have a high burden of typhoid fever including incidence of multi-drug resistance challenge that cities like Hyderabad in Pakistan and Bangladesh are aiming to tackle currently. Bharat Biotech is working with the consortium in carrying out field trials in different countries to evaluate the efficacy of TypbarTCV.
Typhoid is caused by the bacterium Salmonella Typhi, and is responsible for around 20 million new infections and 2,00,000 deaths each year, mainly in South and South East Asia and Africa.
The Product Summary File has been submitted to World Health Organisation for prequalification. WHO prequalification would allow for UNICEF to procure this vaccine for low-income countries where the disease burden is very high.
TypbarTCV is currently licensed in India, Nigeria, and Nepal, with registrations underway in Malaysia, Turkey, Thailand, Uganda, Kenya, Bangladesh, Pakistan, Vietnam, etc among 30 other countries.