A new study questions the need for boosters as the current rate. Researchers at Oregon Health & Science University report finding high levels of antibodies in the blood of patients who were vaccinated years ago, and their presence suggests that current recommendations for boosters for such conditions as measles, mumps and tetanus could be revised.

The persistence of the antibodies suggests that current recommendations for booster shots for some common conditions could be revised, because protection may last for life, according to the study, which was published this week in The New England Journal of Medicine (subscription may be required).

Tetanus shots, for instance, could be given once approximately every 30 years instead of once every 10 years, which is the current recommendation. Boosters may be safe and, of course, big business, but ultimately unnecessary, Mark Slifka, one of the authors, tells The Wall Street Journal. “If we can continue to improve our vaccines, someday we might be able to give one shot and give lifelong immunity,” says Slifka, associate professor at the Oregon university’s Vaccine and Gene Therapy Institute.

But John Treanor, a physician specializing in infectious diseases at the University of Rochester in New York state, tells the Journal that before the health-care system eliminates boosters, more study is needed on outbreaks of certain diseases and declining vaccine efficacy. “I think this is helpful and great to have,” he says, about the study. “I don’t know if this is so definitive.”

The study authors note that the efficacy of vaccines doesn’t apply across the board: children frequently need chickenpox booster shots after five years because the vaccine antibodies aren’t as potent as the antibodies created by the disease itself, the Journal writes. The researchers analyzed 630 stored blood samples from 45 patients. With each sample, the authors analyzed the decay rate for antibodies from vaccines for measles, mumps, rubella, varicella-zoster virus, and Epstein-Barr, the herpes virus that causes mononucleosis.