noun, plural elegies. 1. a mournful, melancholy, or plaintive poem, especially a funeral song or a lament for the dead. 2. a poem written in elegiac meter. 3. a sad or mournful musical composition. Origin of elegy.
Hepatitis D virus (HDV) is an RNA virus that is structurally unrelated to hepatitis A (HAV), hepatitis B (HBV), or hepatitis C virus (HCV). It was discovered in 1977. HDV causes a unique infection that requires the assistance of viral particles from HBV to replicate and infect other hepatocytes.Its clinical course is varied and ranges from acute, self-limited infection to acute, fulminant liver failure.
History and Development of Flu Vaccines. In 1933, researchers discovered that viruses (influenza virus types A, B, and rarely C) cause influenza (flu). Prior to 1933, a bacterium named Haemophilus was thought to cause the flu. In 1938, Jonas Salk and Thomas Francis developed the first vaccine against flu viruses.n 1933, researchers discovered that viruses (influenza virus types A, B, and rarely C) cause influenza (flu). Prior to 1933, a bacterium named Haemophilus was thought to cause the flu. In 1938, Jonas Salk and Thomas Francis developed the first vaccine against flu viruses.