A new study found that the cases of Varicella or Chickenpox in the United States have dropped significantly since the vaccines were made available some 20 years ago.
In 1996, the one-dose varicella vaccine was introduced. This breakthrough resulted in the drastic decline of varicella cases; however, outbreaks were still recorded hence, experts were driven to adopt the two-dose immunization program starting 2007. Previous investigations show that between 1994 and 2002, the cases of outpatient visits and hospital admissions due to varicella decreased by 88 percent and 59 percent respectively. In the latest study, the researchers updated the health care utilization information linked to varicella as 10 years' worth of information have been added to previous records. The said additional data were collated at a time when the transition from the one-dose to the two-dose vaccination program was gradually being stabilized.
The researchers conducted a retrospective cohort study by utilizing the data available at the Truven Health MarketScan. The participants were aged between 0 and 49 years old, who received their pre-vaccination dose between 2006 and 2012 and their two-dose varicella vaccination period occurred between 2006 and 2012. The authors analyzed the patterns of the subjects' outpatients visits, hospital admissions, laboratory testings, outpatient antiviral therapies and pediatric strokes related to varicella.
The findings of the study, published in the Journal of the Pediatric Infectious Diseases Society on Wednesday, Aug. 12, show that varicella-related outpatient consults decreased by 84 percent in 2012 compared to the findings during the pre-vaccination period. The decline of varicella hospitalizations during the pre-vaccination and two-dose vaccination periods were 93 percent and 38 percent respectively. More patients underwent laboratory testings, as the 6 percent rate in 2003 shoot up to 17 percent in 2012. Antiviral medication administration remained stable, with 17 percent of the subjects claiming that they received such therapies. Pediatric strokes did not undergo declines from 1994-2012.
"We found that, in our study, rates for varicella in the U.S. continued to decline as the varicella vaccine program has become fully implemented," says Jessica Leung, MPH, co-author from the Centers for Disease Control and Prevention in Atlanta, Georgia.
In conclusion, the experts claimed that they saw notable decrease in the rates of Chickenpox since the one-dose vaccine was first launched in the US and are continuously observing more drops in cases after the two-dose vaccination program.
Photo: Teddy Kwok | Flickr
