Chickenpox Death Rate Drops After Start of Varicella Vaccination Program

Chickenpox is a contagious viral illness that is caused by the varicella zoster virus.  The hallmark of the disease is an itchy vesicular rash that can leave pockmarks.  The virus has an airborne mode of transmission and spread when an infected individual coughs or sneezes.  The disease is mild in young children but can be very severe in older individuals.  Chickenpox infection during pregnancy can be devastating and can result in congenital malformation of fingers and limbs, encephalitis, microcephaly, and ultimately the death of the unborn child.  In 1995, a varicella vaccination program was implemented in the United States and has become part of the routine childhood immunization schedule.  One dose does not provide lifelong protection, and a second booster shot is needed five years after the first.  Researchers lead by Dr. Mona Marin from the Centers for Disease Control and Prevention have recently published results showing a dramatic drop in the death rate from chickenpox as a result of the varicella vaccination program.  The results of the study were published online in the journal Pediatrics.  It was previously reported that the first six years of the vaccination program saw a 66% drop in the rate of death from chickenpox.  The current study examined the data from the years of 2002 to 2007.  National data on deaths from chickenpox was obtained from the Mortality Multiple Cause-of-Death records from the US National Center for Health Statistics.  During the 12 years of the one dose vaccination program, the researchers found that the average mortality rate from varicella virus infection dropped by 88% from 0.41 per million people to 0.05 per million people.  The decline in mortality occurred in all age groups but individuals younger than 20 years and younger than 50 years had an extremely high reduction, 97% and 96% respectively.  The authors wrote, “The impressive decline in varicella deaths can be directly attributed to successful implementation of the 1-dose vaccination program. With the current 2-dose program, there is potential that these most severe outcomes of a vaccine-preventable disease could be eliminated”.  Hopefully, in the near future chickenpox deaths can become only a distant memory of the most senior physicians in the medical field.

Reference:

Mona Marin et al. “Near Elimination of Varicella Deaths in the USA After Implementation of the Vaccination Program” Pediatrics published online July 25, 2011 (doi: 10.1542/peds.2010-3385)

Tagged as: chickenpox, Dr. Mona Marin, mortality rate, vaccination, varicella vaccination program, varicella zoster virus