A previous News Blog  discussed the finding that a previous infection with one strain of Dengue fever can sensitise a person so that infection with a second strain will be more severe than would otherwise have been the case. There is new evidence that such Antibody Dependent Enhancement (ADE) may cross species barriers, such that a person sensitised with one type of flavivirus, say Dengue, is more likely to have a severe illness if inflected with another flavivirus, such as the Zika virus. Such cross species ADE has obvious implications for vaccination programmes. In previous News Blogs  we have drawn attention to cross-resistance such that vaccines protect against non-target organisms (e.g. small pox vaccines provide protection against HIV). The above paper shows that the reverse can also occur. This is not the first time that vaccination has been shown to have adverse consequences.
— Richard Lilford, CLAHRC WM Director
- Lilford RJ. Three hits hypothesis. NIHR CLAHRC West Midlands News Blog. 7 April 2017.
- Cohen J. Dengue may bring out the worst in Zika. Science. 2017; 355(6332): 1362.
- Lilford RJ. Two papers try to answer the question – do vaccinations for one communicable disease offer protection against others? NIHR CLAHRC West Midlands News Blog. 27 January 2017.
- Guzman MG, Alvarez M, Halstead SB. Secondary infection as a risk factor for dengue hemorrhagic fever/dengue shock syndrome: an historical perspective and role of antibody-dependent enhancement of infection. Arch Virol. 2013; 158(7): 1445-59.