Life is an injection

Today is World Health Day. It is an apt occasion to look back at the progress India has made in its fight against preventable diseases, and the importance of life-saving vaccines.

Diarrhoeal diseases kill nearly 600,000 children every year. They are one of the foremost causes of infectious morbidity, second only to acute respiratory infections.

Unfortunately, India is a major contributor to the global burden of diarrhoeal diseases. The number of people dying from diarrhoeal diseases have come down, thanks to better antibiotic availability and utilisation of oral rehydration therapy. But the burden still remains high and is one of the principal causes of morbidity and mortality, especially in children.

Enteric bacterial infection (linked to intestines) is a major cause of diarrhoea throughout the world, especially in low- and middle-income countries. The WHO says 1.1 billion people drink unsafe water and the vast majority of diarrhoeal disease in the world (88 per cent) is linked to unsafe water, sanitation and hygiene. In developing countries, enteric bacteria and parasites are more prevalent than viruses and typically peak during the summer.

Recent studies show that bacterial pathogens such as Vibrio cholerae (causes cholera), Escherichia coli , Shigella spp. and Campylobacter jejuni account for moderate to severe diarrhoea in India. Among these, rotavirus and norovirus are the main pathogens responsible for acute diarrhoea.

Rotavirus infection accounts for a third of global child deaths attributable to diarrhoea. It cannot be controlled by antibiotics, nor are there any specific drugs for it. It is seen that almost all the children across the globe will suffer at least one rotavirus infection, if not more, in their lifetime. It is even seen in the developed world. Immunising children with a vaccine is clearly the way to effectively reduce rotavirus-related morbidity, mortality and associated medical costs.

Several rotavirus vaccines formulated for oral administration to infants have been shown to be highly effective in reducing the incidence of rotavirus gastroenteritis. An indigenous vaccine developed in India has been shown to be efficacious and is currently awaiting licensure.

An important concern is the emergence of cholera across the globe. Recent outbreaks in Cuba, Haiti and Zimbabwe show it can cause enormous loss of human lives. Cholera is endemic in India, stays in the environment especially in coastal areas, and as such, the lower Gangetic plain is called ‘homeland of cholera’. It is a pity that despite an estimated annual burden of two to four million cases, we react only when an outbreak hits.

Control of cholera depends on the long-term strategy of improving water quality and sanitation systems. That said, it is difficult to achieve this in resource-poor settings (as seen in India). Thus, vaccination for cholera can be an important short-term preventive approach along with other efforts.

A low-cost, bivalent, killed whole-cell oral cholera vaccine is currently made in India and has also received licensure from the Drug Controller General of India. It has proven efficacy and safety and confers 65 per cent protection at the end of five years following vaccination. Recently, the Strategic Advisory Group of Experts on Immunisation of the WHO recommended the use of this vaccine in endemic areas.

Given the morbidity diarrhoeal diseases bring on, it is critical pursue further research in this area.

The writer is Executive Director, Translational Health Science and Technology Institute

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