While the Nipah virus (NiV) fever outbreak in Kerala has caused 10 deaths within a fortnight and fight is on to prevent spread of the epidemic, a section of healthcare experts point out the reluctance of cash-rich global drug manufacturers, to develop effective drugs or vaccines for such infectious diseases.
The Nipah virus (NiV) induced fever causes high fatality rate (40-80%) and spreads mainly through bats, pigs and other animals. It was first identified in pig farms of Kampung Sungai Nipah, Malaysia in 1998. Although the Nipah virus infection has not been identified in Malaysia or Singapore since 1999, it has re-surfaced with high fatality rates among humans on an almost annual basis in Bangladesh since 2001.
"What makes the situation tougher is that there is no vaccine or medicine for the disease. The only form of treatment is supportive medicines and palliative care. When the infection occurs in humans, it has a range of clinical presentations, from asymptomatic infection to acute respiratory syndrome and fatal encephalitis," says Dr K K Aggarwal, past president of the Indian Medical Association (IMA) and president of the Heart Care Foundation of India (HCFI).
According to the US Centers for Disease Control and Prevention, although ribavirin has been shown to be effective against Nipah virus in vitro, it is yet to be proven as an effective treatment in humans.
Sources point out that even after many decades of identifying most of the dreaded modern epidemics that range from Ebola to SARS or Nipah virus and endemic to places like Africa or South East Asia, effective diagnostics, therapeutics, and vaccines are yet to be developed for these disease spreading pathogens.
The WHO estimates that while the total health related research and development expenses (without neglected diseases) annually were to the tune of $1,91,756 million globally (2016), the public sector R&D funding for neglected diseases was only $2,673 million and the private sector R&D for neglected diseases is a mere $527 million. Compared to this, the total global pharmaceutical research and development (R&D) spending in 2017 was an estimated $158 billion, mainly on cancer and cardio-vascular drugs that have market round the year and across the globe.
Development of a new pharmaceutical drug from laboratory to market takes about 10-12 years and involves investment to the tune of over a $1-2 billion. However, lack of an assured market for the product prevents global drug majors from risking such huge investments on neglected diseases, which are seasonal and endemic to certain geographies, especially poor countries, sources say.
They note that in 2015, the World Health Organization (WHO) had developed a 'Research and Development (R&D) Blueprint for Action to Prevent Epidemics', following the Ebola epidemic outbreak in West Africa. The WHO had suggested then 'priority pathogens of concern R&D roadmaps' for Ebola/Marburg, Nipah and Lassa viruses. In a May 15th webinar, hosted by the Center for Infectious Disease Research and Policy (CIDRAP), University of Minnesota, the agency which is working on the roadmap for Nipah virus in co-ordination with the WHO, claimed the timeline for the Nipah virus roadmap is currently on schedule.
"The final draft of the roadmap document is anticipated in June, after incorporating additional feedback from stakeholders. However, the document will continue to be revised with input from WHO and other key partners before its final publication in August or September," said Michael T. Osterholm, director, CIDRAP.
To date, a Nipah Roadmap Taskforce of 13 members have already participated in an expert review meeting and have continued to provide a review of the roadmap document, he said.
However, a drug or vaccine to save lives from the fruit bat causing Nipah virus fever is years away.
