"Since the introduction of the chickenpox vaccine, we have known how effective it is in preventing children from contracting that itchy and painful disease, but we set out to determine if the vaccine would also reduce risk of herpes zoster", Sheila Weinmann, a researcher at Kaiser Permanente and study lead investigator, said in a news release.
At the end of the research, they found that the children who were vaccinated with the chickenpox vaccine had 78 percent lower rates of shingles than the children who were not vaccinated.
The study reinforces the benefits of routine chickenpox vaccination to also prevent pediatric shingles, the researchers concluded.
Overall over the 12-year period studied, the rate of shingles cases among all children in the study fell by 72%, as increasing numbers of vaccinated children likely led to a decrease in infections among unvaccinated children through a phenomenon called herd immunity.
Weinmann said the overall drop was large because so much less of the virus was circulating in the general population.
Gershon was not involved in the research, but she wrote a commentary on it that the journal published in conjunction with the study. They wanted to investigate whether varicella, or chickenpox vaccine, would either protect against or promote the development of shingles. "Now we have to find out how long the protection will last".
Since 2007, a booster at 4 and 6 years of age also has been recommended.
Dr. David Fagan, vice chair of pediatrics at Cohen Children's Medical Center in New Hyde Park, N.Y., said shingles isn't usually severe in children, unless their immune system is compromised.
While the condition is more common in older adults whose immune systems are waning, children too can develop shingles. Years later, the virus may reactivate as shingles. "As you get older, the immune system gets exhausted", she explained.
To see how varicella vaccine would affect the rate of shingles in kids, the researchers collected health information on 6.4 million children, ages 1 to 17.
Varivax is the chickenpox-only vaccine while Proquad provides protection from measles, mumps, rubella, as well as varicella. By 2014, it ranged from 82% to 91%, the study said. But over the study period, the rate of shingles cases kept declining, which may be a hopeful sign for longer protection.
Strikingly, the rate of shingles incidence was 78% lower among vaccinated children compared with unvaccinated children.
The varicella vaccine was added to the CDC childhood immunization schedule in 1995. They were being exposed to varicella virus before the unvaccinated children were. It is estimated that about one-third of people who had chickenpox will go on to have at least one bout of shingles.