Immunization Science

Children with chickenpox are more likely to have invasive group A streptococcal (IGAS) infections, which can be fatal. A new study suggests that the chickenpox vaccine has reduced the number of IGAS hospitalizations.

Persons vaccinated against chickenpox could contract a mild form of the disease if exposed to it, which is known as breakthrough varicella. This study looked at how contagious  these breakthrough varicella cases are.

How effective is varicella (chickenpox) vaccine over time?  Researchers have found that although the vaccine’s effectiveness to protect against all chickenpox symptoms decreases after the first year, it is still protective after 8 years.

A chickenpox vaccination program implemented in 1995 at the Kaiser Permanente Northwest (KPNW) HMO in Portland, Oregon, significantly reduced the incidence of chickenpox among all children attending the clinic.