Incidence of shingles 78% higher in unvaccinated children

Children unvaccinated for chickenpox after its introduction had an incidence of 78% of herpes zoster or HZ infections higher than vaccinated children, according to a study published in pediatrics.

Sheila Weinmann, PhD, an epidemiologist with the Kaiser Permanente Northwest Center for Health Research, and his colleagues wrote that routine vaccination against chickenpox had been introduced in the United States in 1996. Studies since then have shown a "decline to varying degrees." Of the incidence of shingles.

Weinmann and colleagues badyzed electronic medical records of shingles cases among 6,372,067 children aged 0 to 17 years. All cases were reported between 2003 and 2014.

The crude incidence rate of HZ infection was 74 cases per 100,000 person-years. Researchers wrote that the rate of infection in vaccinated children was 78% lower than the rate for unvaccinated children – 38 versus 170 per 100,000 person-years (P <.0001).

During the study period, the overall incidence of shingles decreased by 72% (P <.0001). Throughout the study, annual rates of shingles in vaccinated children were consistently lower than those of unvaccinated children.

"With this study, we are reinforcing the benefits of preventing shingles in children through varicella vaccination," wrote Weinmann and colleagues. "Future rates of pediatric herpes zoster may be lower than those reported here during a two-dose vaccination program for varicella in the maturation phase."

Like wild-type varicella-zoster virus (VZV) infection, a vaccine strain virus may establish a latent infection that may eventually reactivate, thereby causing shingles. however, Anne A. Gershon, MD, Professor of Pediatrics at the Institute of Human Nutrition at Columbia University, wrote in a related editorial that the findings of the study by Weinmann and his colleagues demonstrated that vaccine-type VZV was less likely to reactivate compared to wild-type VZV.

"We must continue to work to immunize all children against chickenpox to protect our population from wild-type VZV," she wrote. "Fortunately, antiviral treatment is also available for unvaccinated people who develop chickenpox or shingles, but vaccination is, as usual, preferable." – by Katherine Bortz

Disclosures: Please refer to the editorial for Gershon's relevant financial information. Weinmann and colleagues do not report any relevant financial information.