Evidence indicates that CYD-TDV is partially effective in preventing infection, but may lead to a higher risk of severe disease in those who have not been previously infected and then do go on to contract the disease. It is not clear why the vaccinated seronegative population have more serious adverse outcomes. A plausible hypothesis is the phenomenon of antibody-dependent enhancement (ADE). American virologist Scott Halstead was one of the first researchers to identify the ADE phenomenon. Dr. Halstead and his colleague Dr. Phillip Russell proposed that the vaccine only be used after antibody testing, to rule out prior dengue exposure and avoid vaccination of sero-negative individuals.Common side effects include headache, pain at the site of injection, and general muscle pains. Severe side effects may include anaphylaxis. Use is not recommended in people with poor immune function. Safety of use during pregnancy is unclear. Dengvaxia is a weakened but live vaccine and works by triggering an immune response against four types of dengue virus.Dengvaxia became commercially available in 2016 in 11 countries: Mexico, the Philippines, Indonesia, Brazil, El Salvador, Costa Rica, Paraguay, Guatemala, Peru, Thailand, and Singapore. In 2019 it was approved for medical use in the United States. It is on the World Health Organizations List of Essential Medicines. In Indonesia it costs about US$207 for the recommended three doses as of 2016.In 2017, the manufacturer recommended that the vaccine only be used in people who have previously had a dengue infection, as outcomes may be worsened in those who have not been previously infected.
Acral fibrokeratoma (also known as an "Acquired digital fibrokeratoma," and "Acquired periungual fibrokeratoma": 668 ) is a skin lesion characterized by a pinkish, hyperkeratotic, hornlike projection occurring on a finger, toe, or palm. : 609 : 1817

See also
Skin lesion
List of cutaneous conditions


== References ==