Viral Hepatitis E (HEV) series & Nepal - Where are we in its vaccine development? (Part 3)

     As 6 part of  writing series on Viral Hepatitis E (HEV) and Nepal, I am now activating neurons in some part of neo cortex of my brain, so I can write meaningfully to understand better this HEV disease in particular. I am repeating again, why I am so interested to write about this infectious disease is because this is very personal to me !! In HEV series (Part 1), I wrote of myself getting to know  this disease closely. When I remember those days of extreme weakness with bouts of vomiting with incessant nausea that gripped your guts, I even now feel the suffering. In HEV seried (Part 2), i have tried to be more objective and I did pretty satisfying job in quickly reviewing all the papers so far published related to HEV in Nepal. It is comforting to know so much have been studied on HEV and now, we do know the basic epidemiology including the genotypic mapping of HEV circulating in Nepal. Notably, some of the human phase of clinical trials were also conducted in Kathmandu among Nepalese population. 

       

Source: www.google.com (for purely academic purpose)

     However, there is only one voice that we have heard and now i have started to understand why the candidate vaccine meant for HEV is still not there in public health or even in private market arena? In this aspect, I read a short letter in response to a paper published in a leading science journal. Dr. Buddha Basnyat (a senior scientist seriously studying infectious diseases in Nepal) has raised a serious ethical question as to why vaccine industry or research organizations who have invested so much of their time and money to develop HEV vaccine and now, there is no vaccine when there is high demand in the community. In the letter titled Neglected HEV and Typhoid Vaccine, he raises a serious question, " These vaccines against hepatitis E.......are not available, despite their proven efficacy and safety. If GSK, Walter....were not going to develop these vacciness or make them available after their successful testing in Nepal and Vietnam, why were they tested? And if these organizations will not develop them further, is there a responsibility to make them available to others who might?"

     

Source: http://www.afrims.org/afrimsprofile/p24.htm

    In response to this series question, where justice as a fairness so the fruits of science have to be available if they were tested in a population in its development. In next part, I will try to throw light in understanding what is the crux of delay in bringing out HEV vaccine in the community where it is needed the most. So the question comes, is it related with financing or business aspect of vaccine development? or is it related with regulatory or purely scientific challenges that have to be solved so that we can deliver safe, affordable and effective vaccine once and for all?

Short Note on Dengue in Nepal

Nepal is endemic for many vector-borne diseases, including malaria, kala-azar, Japanese encephalitis, and lymphatic filariasis. Diseases related with poverty are major public health problem. This is further compounded by deteriorating environmental conditions with tropical/sub-tropical climate. It is also aggravated by increased vector amplification and disease transmission due to urbanization, increasing population density and climate change effects. In recent years, there are increasing formal and informal reports of new emerging and re-emerging infectious diseases. Among those, Dengue fever (DF) which is proved to be associated with high morbidity and mortality, is posing increasing public health threat. This means that preventive and control measures against DF cannot be effective, if we lack good epidemiological understanding of the disease in question.

There was no documented indigenous case of dengue infection in Nepal until the Sept-Oct outbreak of 2006. During this outbreak, all Dengue serotypes were identified from few Hill (Kathmandu-no history of travel) and Terai districts (Banke, Parsa, Dhading, Jhapa, Rupendehi, Dang and Kapilbastu) of Nepal. (Malla S, Thakur GD, Shrestha SK, Banerjee MK, Thapa LB, Gongal G, Ghimire P, Upadhyay BP, Gautam P, Khanal S, Nisaluk A, Jerman RG, Gibbons RV. Identification of all Dengue serotypes in Nepal. Emerging Infectious Diseases 2008; 14 (10): 1669-70). The first report of dengue virus isolation was in 2008 involving a Japanese patient returning from Nepal in October 2004. According to genomic study, the virus was closest to a dengue virus from India. Basu Dev Pandey et al (August – November 2006) also reported serologically confirmed DF from Hill (Kathmandu and Sindhuli) and Terai districts (Bardiya, Salyan, Birgunj and Dang) among febrile patients. Only 1 case had travel history outside of their residence. Many entomological studies of mosquitoes carried since eighties to recent, have revealed the presence of dengue vectors in major urban areas of Hill and Terai districts. Previously no Aedes aegypti was recorded in Nepal. These evidences strongly suggest the existence of an epidemic cycle of Dengue in Nepal. 

However, there are few important points that need to be taken into consideration.

• Inadequate evidence to explain actual burden and epidemiological characteristics of the dengue fever in the Nepal.
• Health professionals do not usually consider dengue as a differential. There is also under or no reporting in the absence of diagnostic facilities at the field level. It may be reported as viral fever or pyrexia of unknown origin (PUO).
• Nepal has no dengue surveillance programs, and lack effective preventive and control measures against DF. 
• It is alarming situation that the DF is observed in patients from hilly districts with no travel history.