When 18-month-old Asim was taken to the doctor, his father assumed that his fever-stricken son was suffering from the common cold. But when the doctor prescribed a ‘powder wala syrup’, an antibiotic, his father instantly knew something was wrong.
“I just knew it was typhoid,” he said, adding that he came to this conclusion based on his past experience with the disease. “Some time ago, I also had typhoid and my symptoms were the same as what my son was experiencing.” Asim was taken to a hospital immediately where a test confirmed his father’s suspicion. He remained there till he made a full recovery and returned home healthy and well.
Fortunately for infants like Asim, the typhoid conjugate vaccine is now set to become part of the Expanded Programme on Immunisation, EPI, making Pakistan the first country among GAVI-eligible low-income nations to introduce the TCV vaccine.
“While typhoid vaccine is available, it is a polysaccharide vaccine which cannot be administered to children under two years of age because it doesn’t work on them,” explained Dr Fyezah Jehan, assistant professor of paediatrics and child health at AKU. “The single-dose conjugate vaccine has long-lasting immunity and can be administered to children as little as six months till 15 years of age.”
The conjugate vaccine’s inclusion in routine immunisation is the result of the compelling findings of a study conducted by AKU researchers in 2016. Led by Dr Farah Naz Qamar, associate professor, Department of Paediatrics and Child Health, the study found that there was a significant burden of an antibiotic-resistant strain – the XDR S. typhi strain -- in Pakistan. The team suspected the abysmal sewage and water system was the culprit. In most poor neighbourhoods, sewage lines are non-existent or are faulty, thus leaving potable water supplies vulnerable to contamination. More than 5,000 cases of the drug-resistant strain have been reported in the country, making it a major public health concern.
The findings of the study convinced the government to file an application to GAVI, a global, public-private partnership committed to increasing access to immunisation, to introduce Typbar-TCV vaccine in the country’s routine immunisation programme.
“Based on the study conducted by researchers at AKU, we filed the application to make the TCV vaccine part of routine immunisation,” said Dr Zahoor Baloch, project director, EPI, Sindh. “Had it not been for these findings, the high burden of drug-resistant typhoid would have gone unnoticed.” Around 13.5 million doses of the vaccine are expected to arrive by October this year, he added.
Pakistan began to experience the world’s first outbreak of XDR S. typhi strain in 2016 in Hyderabad, which led to the study in question that showed evidence of a significant burden in the area.
Given the huge burden of typhoid in South and South-east Asia along with sub-Saharan Africa, the introduction of TCV as part of routine immunisation in Pakistan could pave the way for global typhoid control particularly since the growing threat of antimicrobial resistance looms large. Unless the vaccine’s use is standardised, XDR typhoid could become an endemic in Pakistan and turn the clock back 70 years, cautioned Dr Jehan.
This is not the first time that AKU’s wide-ranging healthcare initiatives have strengthened routine immunisation programmes in Pakistan. Earlier research findings compelled the government to file similar applications with GAVI which in turn led to the introduction of PCV-10 (for pneumonia and meningitis) and HIB conjugate vaccines in EPI.
It is also worth mentioning that the control and prevention of water-borne diseases such as typhoid is a global health priority with targets under goal 3 of the Sustainable Development Goals calling for the eradication of such diseases by 2030.