A 1995 vaccine cut U.S. chickenpox cases by nearly 97%
Varicella zoster virus spreads on coughs and sneezes days before the classic itchy rash appears. Since the United States introduced varicella vaccine in 1995, infections have plunged nearly ninety-seven percent—yet worldwide, hundreds of millions of chickenpox and shingles cases still occur.
Chickenpox, or varicella, is a highly contagious, vaccine-preventable herpesvirus infection. It produces a blistering, itchy rash that usually begins on chest, back, and face before spreading. Airborne droplets and contact with lesion fluid transmit it. Incubation lasts ten to twenty-one days; contagiousness runs from one to two days before the rash until every lesion has crusted, typically four or five days of vesicles.
The U.S. vaccine, introduced in 1995, protects roughly seventy to ninety percent of people from disease and more against severe illness; many countries recommend routine childhood shots, and vaccination within three days of exposure can still help. In 2013 there were about 140 million chickenpox and shingles cases worldwide. Before routine immunization, annual cases roughly matched births; U.S. infections later fell nearly ninety-seven percent. The phrase "chicken pox" appears in print by 1658, with folk etymologies linking the name to mildness or beak-like marks.
Adolescents and adults often feel nausea, appetite loss, muscle aches, and headache before the rash and low fever. Intense itching marks the blister stage; palms, soles, and genitals can be involved. Painful oral ulcers may precede the skin rash by a day or two, and watery nasal discharge with live virus can make someone contagious before anyone notices spots. That early silent spread is why isolation after the rash alone never fully contained school outbreaks before vaccines.
Source: Chickenpox
