With the alarming rate of risks attached to meningococcal meningitis, Federal vaccine advisers have now recommended a booster dose of the vaccine to 16-year-olds and also suggest people aged 11 to 64 to get a booster to protect against whooping cough, diphtheria and tetanus.

The booster dose was suggested as the earlier dose of vaccine might only work for five years or less. The hope is that a booster dose at 16 would yield protection through the first few years of college, when outbreaks occur most often.

Debating on when and how many doses should be suggested, members of the Advisory Committee on Immunization Practices noted that the current strategy prevents 9 deaths each year, delaying the first dose would prevent 14 deaths and adding a second dose would prevent 24. The vaccine is about $100 a dose, and the disease is rare. So adding a second dose ensures that every death averted would be expensive.

Since the federal government pays for about half of all vaccines, the additional cost would be partly borne by taxpayers. The committee voted 6 to 5 to support a booster, but for the recommendation to take effect, the Department of Health and Human Services would need to endorse it.

Dr. Janet Englund, a committee member from Seattle Children’s Hospital, said that delaying the vaccine by three or four years would result in fewer teenagers being vaccinated. Fewer 16-year-olds are vaccinated compared with preteenagers, she noted. And because teenagers may drop out of high school, she said, “By moving the age up, I very strongly fear we’re going to be missing at-risk youths.”

Dr. James Turner, a liaison representative to the committee from the American College Health Association, fears that more meningitis cases would be popping up on college campuses, if the vaccines were truly so ineffective after five years. But he said a recent survey of 207 schools found just 11 cases, and fewer than half of those cases would have been prevented by vaccination because of differences in strains of the disease. He also noted that making a quicker decision on a booster might help.

Meningococcal meningitis can be fatal. It strikes so quickly that often only a day passes between the first signs of illness and the death of the child. Lori Buher of Mount Vernon, Wash., told the committee about how her 6-foot-4, 14-year-old son, Carl, was playing football one day and was being airlifted, near death, to Seattle Children’s Hospital the next. His heart stopped three times during the flight.

Carl survived but lost legs below the knee, as well as three fingers and the use of his knuckles. He underwent 11 skin graft operations. She urged a booster shot, she said, because vaccination at age 11 would have saved Carl from his illness. His illness struck in 2003, before the current vaccines were approved.

“I can’t tell you what it would have meant if we’d been able to vaccinate him at 11,” Ms. Buher said.

The committee also discussed a growing epidemic in California of whooping cough, also known as pertussis. The State so far this year has had 6,257 cases, the most since 1960. Ten infants have died in California this year, and cases have risen nationally as well.

One way to prevent infant deaths is to vaccinate family members. Therefore, the committee voted to recommend a booster shot of a vaccine against diphtheria, tetanus and pertussis to those between ages 11 and 64, and to those over 65 if they come in close contact with infants.