Half Doses of Flu Vaccine for the Healthy Weighed

Worried about a possible shortage of this winter’s flu vaccine, federal health officials are studying whether it would be safe to stretch supplies by giving some healthy Americans half a dose, reserving full-strength vaccine for the elderly and ill who need it most.

Experts won’t know until October if such a plan would work. That’s when they expect results of a clinical trial to measure whether half a vaccine dose revs up certain people’s immune systems enough to protect them. Six hospitals, including Childrens Hospital Los Angeles and UCLA Medical Center, will start recruiting volunteers for the study next week.

Meanwhile, the government is warning doctors and clinics that flu shots will be shipped late this year, meaning the healthy will have to delay their shots while the elderly and people at high risk of dying from the flu get vaccinated first.

The government probably won’t know until September if there also will be a significant shortage of vaccine doses.

“It’s very clear there will be a delay in availability of influenza vaccine,” Dr. Nancy Cox of the Centers for Disease Control and Prevention said Friday. But “we don’t know for sure how much vaccine will be available.”

The problem: Manufacturers had trouble growing one of the influenza strains used in this year’s vaccine. Because different flu strains circle the globe each year, a new flu vaccine must be brewed annually. In addition, the Food and Drug Administration earlier this year ordered two of the nation’s four vaccine makers to correct manufacturing problems in their factories, delaying production.

The flu kills about 20,000 people every year. Most at risk are people older than 64 and people of any age who have chronic heart or lung diseases, including asthma, or who have diabetes, kidney disease or a weakened immune system.

If doctors get early shipments of flu shots in September or October, they should vaccinate high-risk patients as soon as possible, Cox advised.

But companies, civic groups and others should postpone until November--a month late--their annual vaccination campaigns, she said.

Information on how to volunteer for the half-dose vaccine study will be posted Tuesday on the Internet site: https://clinicaltrials.gov.