Stanford University researchers have found that giving an inactivated form of chickenpox vaccine to adults can reduce the risk of herpes zoster (shingles), which strikes elderly people and people with weakened immune systems.
Even among healthy adults the risk of shingles rises each decade after age 60, increasing to one in five people in their 80s. Patients who have had a transplantation are at high risk of the condition, because their immune system is impaired.
Shingles is triggered by the same virus that causes chickenpox. Once someone is infected by the virus, it remains latent in nerve cells and can be reactivated when the immune system is weakened. It causes an itchy, burning rash and shooting pains that can last for years.
Dr Ann Arvin, chief of paediatric infectious diseases at Lucille Packard Children's Hospital and a professor of microbiology and immunology in Stanford University's medical school, and colleagues decided to see whether inactivated chickenpox vaccine could protect patients with cancer who received haemopoietic cell transplants against such reactivation. They used a heat inactivated preparation of the childhood vaccine, made for purposes of investigation by Merck and not available commercially.
Reporting in the New England Journal of Medicine (2002; 347:26-34), the researchers said that seven of 53 patients who received one dose of the inactivated vaccine within 30 days before the transplantation, followed by three doses after the transplantation, developed shingles, compared with 17 of the 56 participants in the unvaccinated control group.
The researchers believe that administration of inactivated vaccine could benefit other people at risk of shingles and that the strategy of vaccination before transplantation could protect other patients against other viruses and bacteria.