TANZANIA and other countries are set to benefit from Indian developed typhoid vaccine, which can protect adults and children against the deadly ailment.
Developed by India-based Bharat Biotech Limited, the vaccine aims at under two children, the hardest hit victims, with hopes of preventing over half of all typhoid infections.
The new results from Oxford University's typhoid vaccine study published in The Lancet medical journal offer exciting evidence that the vaccine, combined with water and sanitation efforts, will help to make real headway in the fight against the disease.
Director of Preventive Services in the Ministry of Health, Community Development, Gender, Elderly and Children Neema Rusibamayila said she was unaware of the new findings.
She said so far Tanzania has no typhoid vaccine despite the UN World Health Organisation (WHO) endorsing the use of typhoid vaccine in 1999 to decrease the rate of typhoid fever.
"There are immunisation services support offered by Global Alliance for Vaccines and Immunisation (GAVI) from which Tanzania is among the beneficiaries, if the new vaccine is included in the alliance supported drugs, then Tanzania will also benefit," noted Dr Rusibamayila.
She said vaccines which are so far in pipeline include human papilloma virus (HPV) vaccination, with the country scheduled to start vaccinating millions of girls against the devastating women's cancer next year.
Dubbed Vi-TCV, the vaccine has been submitted to WHO for prequalification. The Bill and Melinda Gates Foundation and the European Commission funded trials continue.
The vaccine was tested using a controlled human infection model, which involves vaccinating healthy volunteers and deliberately exposing them to the infection, in a controlled setting, to test whether the vaccine works.
In the study, 112 healthy adult volunteers were randomised to receive either an older typhoid vaccine Vi-PS, the new typhoid conjugate vaccine Vi-TCV or control, non-typhoid vaccine.
After vaccination, each participant ingested typhoid bacteria orally known as the challenge and was then followed medically for two weeks to identify if and when typhoid symptoms appeared. The new Vi-TCV vaccine prevented 55per cent of typhoid infections, similar to that of the older Vi-PS vaccine.
However, when participants developed a positive blood test and showed symptoms, the Vi-TCV vaccine prevented an estimated 87 per cent of typhoid cases compared with only 52 per cent in the Vi-PS group.
Professor of Paediatric Infection and Immunity at the University of Oxford and Director of the Oxford Vaccine Group, Professor Andrew Pollard, who led the trial said although measured in a highly controlled clinical environment with adult participants, the results are particularly promising, suggesting that the new vaccine may dramatically reduce clinical typhoid infections if introduced in high-burden, typhoid-endemic countries.
"The Typhoid Vaccine Acceleration Consortium (TyVAC) is poised to conduct Vi-TCV effectiveness trials in Bangladesh, Malawi and Nepal to measure how effectively this vaccine can prevent infections in children living in high-burden, typhoid-endemic countries," he said in a statement released by Oxford University.
Prof Pollard further said the new trials will build on the promising findings of the challenge study to illustrate the potential benefits of Vi-TCV as a routine childhood vaccine, with potential to prevent typhoid infections and save lives at a population level.
Typhoid is caused by an infection with the bacteria Salmonella Typhi, usually through contaminated water, particularly in parts of South and South-East Asia and Africa with inadequate sanitation. Its symptoms include fever, headache and nausea, loss of appetite, constipation and sometimes diarrhoea.
Children are especially susceptible but the currently licensed vaccines do not confer lasting immunity in children and/or come in inappropriate formats.
According to WHO, typhoid affects about 21 million people and kills 222,000 annually.
Vaccine efficacy was calculated by identifying the proportion of participants diagnosed with the disease in each typhoid vaccine group and comparing that with the proportion diagnosed in the control group.