Before the licensing of the live varicella zoster (chickenpox) virus vaccine in 1995 and subsequent mandating of the vaccine for all children in the U.S., chickenpox itself was considered one of the milder “rites of passage” for children and the vast majority of children experienced the common childhood disease before age ten. Most people have heard about how parents commonly held so-called “chickenpox parties” to expose their little ones to the highly contagious but generally mild viral infection and get it out of the way, instead of chancing the illness cropping up at an inopportune time, in the middle of a vacation for example.
“Reduction of childhood varicella by vaccination might lead to increased incidence of adult zoster.”
When the vaccine was licensed 20 years ago, there were about 50 to 100 deaths related to chickenpox complications reported in the U.S. every year, mostly among the immune compromised, with roughly half being children and half being adults.1 In this post-vaccination era, public health officials present chickenpox as a very serious disease with frequent complications, albeit one that they say has been almost eliminated and rendered harmless thanks to a successful mass vaccination program.
Rarely talked about is the fact that the protective effects of vaccine acquired artificial immunity do not last as long as naturally acquired immunity following recovery from the natural disease. After the CDC recommendation in 1995 that all children get one dose of chickenpox vaccine at between 12 and 15 months old failed to prevent varicella zoster virus from circulating, the CDC added a booster dose of the vaccine in 2007 for children four to six years old.2
Chickenpox in adulthood is associated with a much higher rate of pneumonia and other complications, such as brain inflammation, than when it is experienced as a mild disease by young children. Because the varicella zoster virus lies dormant in the body following recovery from chickenpox, there is another drawback to widespread vaccination: It may lead to an increase in the incidence of herpes zoster (shingles), a painful condition that occurs when the latent chickenpox virus becomes reactivated in later life.