Short answers, pulled from the story.
The varicella zoster virus causes chickenpox and spreads through airborne particles released during coughs or sneezes. Direct contact with fluid inside blisters also transmits the infection to uninfected people.
The incubation period lasts between 10 and 21 days before any visible signs appear on the body. Visible evidence develops 10 to 21 days after exposure to a contagious person.
Non-immune pregnant women and those with suppressed immune systems face the highest risk of serious complications. Infection during the first six months of pregnancy poses greater dangers to the fetus than later stages.
Michiaki Takahashi and his colleagues developed the live attenuated Oka strain vaccine in Japan during the early 1970s. Merck & Co. licensed this specific strain in the United States in 1995.
Paracetamol or acetaminophen may be used to reduce fever without causing liver damage while antihistamines relieve itching and act as sedatives. Aspirin use by someone with chickenpox can cause Reye syndrome, a serious sometimes fatal disease of the liver and brain.