Since routine chickenpox vaccinations were implemented in 1995, yearly rates of chickenpox infections in the U.S. decreased by 80 to 90 percent while the proportion of Americans hospitalized due to the infection has fallen by over two-thirds, a new study by the CDC finds. The vaccine prevented approximately 50,000 hospitalizations between 2000 and 2006. During this period, one in 100,000 Americans was hospitalized for chickenpox complications compared to four per every 100,000 people between 1988 and 1995.
The positive results are great to see in adults, says lead study researcher Adriana S. Lopez, because it’s a sign of herd immunity, in which widespread vaccinations limit disease prevention even in people who are not immune.
ACSH's Dr. Gilbert Ross is equally pleased with the news, noting that the “chickenpox vaccine has been remarkably effective at reducing the rate of complications associated with this virus — known to scientists as the varicella-zoster virus (VZV) — including pneumonia and encephalitis in both children and adults.”
In other vaccine-related news, researchers have found that children between the ages of seven and ten are contracting pertussis, better known as whooping cough, at higher rates. Following an outbreak in California in 2010 in which more than 7,800 pertussis cases were reported, California health officials determined that the last of five DTaP doses given to babies and young children to protect against pertussis isn’t working as long as expected. Instead, a Tdap vaccine — a booster shot administered to adults and adolescents beginning at 11 to 12 years of age — may be introduced for the final DTaP dose. (DTaP stands for diphtheria, tetanus and acellular pertussis. The Tdap shot has the same antigens but provides a lower dose of the pertussis and diptheria antigens.)
Originally introduced in the 1940s and 1950s, pertussis vaccinations have steadily reduced the incidence of whooping cough across the country to an all-time low of 1,010 cases in 1976. However, California has experienced dramatic increases in occurrence of the disease during the last decade, and beginning this summer, the state will require the Tdap shot for entry into middle school or high school unless students have a medical or personal belief exemption.
But Dr. Ross is displeased, as he believes that all states, California included, should revoke the personal belief vaccine exemption. “Children should be vaccinated to protect themselves and those around them before entering any school unless they have a medical exemption, which is very rare, or a documented clerical religious exemption. Based on superstition, parents who choose to not get their kids vaccinated are irresponsibly exposing everyone else to preventable, potentially deadly diseases.”