If you have asthma as a kid you’re 70% more likely to get shingles as an adult, says a new study published in the Journal of Allergy and Clinical Immunology. A group of researchers from the Mayo Clinic looked at the medical records of 371 patients with shingles and 742 control patients who did not have shingles. They found that 23% of the patients with shingles had asthma, whereas just 15% of the patients without shingles had asthma.

“Asthma represents one of the five most burdensome chronic diseases in the US, affecting up to 17% of the population,” said Dr. Young Juhn, the lead author of the study. “The effect of asthma on the risk of infection or immune dysfunction might very well go beyond the airways.”

Dr. Juhn and his colleague’s theory is that because asthma suppresses adaptive immunity, it also increases the patient’s risk of varicella zoster virus reactivation. Varicella zoster virus is what causes chickenpox in children. When the child overcomes chickenpox, varicella zoster remains in their nerve tissue near the brain and spinal cord. Usually, the virus stays dormant. But occasionally it will get reactivated, causing shingles.

Fortunately, there is a zoster vaccine which can reduce the risk of shingles. According to Dr. Juhn, “As asthma is an unrecognized risk factor for zoster in adults, consideration should be given to immunizing adults aged 50 years and older with asthma… as a target group for zoster vaccination.”