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A group of highly contagious viruses that can cause severe diarrhea, mostly in children. Rotavirus is particularly dangerous in infants.

See Measles.

A viral infection with a red rash, enlarged neck lymph nodes, mild fever, and headache. It is spread person to person by coughing or sneezing. Rubella is highly contagious but was declared eliminated in the U.S. Parents should continue to…

The likelihood that an individual will experience a certain event.

Recombinant vaccines use specific pieces of different viruses to help the immune system recognize a disease without causing illness.

How much or how often a vaccine produces a known, "expected" reaction, especially such as fever or sore arm at the injection site. The reactogenicity of a vaccine does not mean it is safe or unsafe.