Originally appearing at endtheneglect.org, Jan 12, 2012…
Albert B Sabin is probably best known for his works and research on the polio virus. During World War II he worked on and developed vaccines for encephalitis (sleeping sickness), sand-fly fever, and dengue fever. It is his work into dengue fever during this time that is now having possible implications for vaccine development today — 60 years later.
Symptomatic dengue infection is characterized by fever, joint and muscle pain, headache, rash, vascular leakage and occasionally hemorrhage. Dengue hemorrhagic fever and dengue shock syndrome are the type of outcomes that result with lack of a proper medical care — something not uncommon across much of the developing world. Severe disease in secondary infections is also a common trait of dengue.
Research into dengue fever during World War II in human volunteers showed that some level of protection from the disease is provided further down the line. After an initial infection with one dengue virus serotype, the individual is protected for a period of time from the disease caused by another serotype; for a limited period of a few months, after which protection becomes serotype-specific.
The findings from two independent studies in Managua, Nicaragua by researchers publishing in Science Translational Medicine now points to the mechanism of such protection.
The fours serotypes of dengue are unique in their interactions to form disease. The interplay of disease and immune system could mean the difference between getting a mild fever and going into a fatal circulatory failure from dengue hemorrhagic fever or dengue shock syndrome.
After the first infection the immune system reacts normally by creating antibodies to fight the viral invaders. It is what happens during the second that lead the researchers to investigate further. Those antibodies, upon a secondary infection, can often be confused when confronted with a second different serotype of dengue. The antibodies don’t fully recognise the second infection, not only that, they seem to help the virus invade the immune system.
This sort of correlation of prior immunity and disease has been observed in an immune-enhancement way with HIV and influenza. It is only dengue that impacts a clinical outcome.
With the development of the first ever dengue vaccine underway, “Our findings have implications for vaccine development and implementation, as the precise genetics of vaccine strains, as well as the timing and serotype sequence of infection prior to and after vaccination, play an important role in determining the outcome of infection,” said the study’s lead author Molly OhAinle in a press release.
Image — source
OhAinle, M., Balmaseda, A., Macalalad, A., Tellez, Y., Zody, M., Saborio, S., Nunez, A., Lennon, N., Birren, B., Gordon, A., Henn, M., & Harris, E. (2011). Dynamics of Dengue Disease Severity Determined by the Interplay Between Viral Genetics and Serotype-Specific Immunity Science Translational Medicine, 3 (114), 114-114 DOI: 10.1126/scitranslmed.3003084