Flu shots may yield to nasal spray
Published Sunday, Dec. 3, 2000, in the San Jose Mercury News
Northern California clinics are test sites for a new kind of flu vaccine administered through a nose spray instead of a hypodermic needle.
BY BARBARA FEDER
Mercury News
In a potential boon for children and adults who hate shots -- you know who you are -- a flu vaccine administered in a simple nasal spray could be available as early as next fall.
Flumist, as the experimental vaccine is known, is undergoing final tests in children at Kaiser Permanente's Northern California clinics and at clinics in Temple, Texas. The Mountain View company that will market the spray hopes to gain U.S. Food and Drug Administration approval in time for next year's flu season.
Because influenza in the United States typically affects 10 to 20 percent of the population and causes some 20,000 deaths each year, flu vaccines have been promoted since 1976 as a way to stem the spread of the disease and prevent deaths, particularly among the elderly and chronically ill. Attention has been heightened this year because of a nationwide delay in the availability of flu vaccine.
The concept of an ``intranasal'' flu vaccine first emerged around 1960, but shifting government and corporate priorities have slowed its development.
At first driven by the U.S. Army, development of new and improved flu vaccines was taken over by the National Institutes of Health in the 1970s when the Army decided flu was no longer one of its priority diseases, said Dr. Linda Lambert, influenza program officer for the National Institute of Allergy and Infectious Diseases, an NIH division.
The agency worked on various vaccine formulations until the early 1990s, when it joined with a private company to market it nationwide. But that company dropped the effort when its own plans changed, and the vaccine did not get the push it needed until the NIH joined with Mountain View-based start-up Aviron Corp. in 1995.
Now, Flumist has been tested on about 10,000 people, most of them children, according to an Aviron spokeswoman.
Yellow-tinged, Flumist is known as a ``cold-adapted'' vaccine, because it has been adapted to trigger antibodies in the nasal passages, which are cooler than normal body temperature. Unlike the ``killed virus'' flu vaccines now in use, which use inactivated influenza viruses to trigger an immune response, Flumist is a ``live attenuated'' vaccine that combines the core of a harmless flu virus with the coat of a virulent strain.
In trials, the vaccine was shown to protect against flu in 93 percent of children who received it, and it had a side benefit: It helped prevent the ear infections with fever that plague many young children. In adults, protection against flu occurred in 85 percent of those receiving Flumist, compared with 71 percent of adults who received injected flu vaccine. Typical side effects include a runny nose or sore throat.
Benefit No. 1: no needle
Doctors see a number of potential benefits to a nasal flu vaccine -- and a few drawbacks.
``It's not a shot. That, for children, is an obvious advantage -- and for adults too, if they were honest about it,'' said Dr. Steven Black, co-director of Kaiser's Oakland-based Vaccine Study Center.
Flumist would not necessarily need to be administered by a nurse, making delivery of the vaccine potentially easier and more widespread. Researchers believe that a nasal vaccine may provide stronger protection against the flu because the virus can be killed in the nasal passages before entering the bloodstream. Then, too, Flumist is believed to protect against a wider variety of flu strains than the traditional flu vaccine.
But the vaccine, at least in its current stage of development, is difficult to transport because it must be frozen until use. Aviron is working on a liquid version of the vaccine that could be shipped around the world.
Remote chance of mutation
Some experts also have voiced concerns about the genetic stability of live vaccines, worrying that the viruses they contain could mutate or combine with another flu virus to create an entirely new strain of influenza. That possibility is considered remote.
At Kaiser Permanente, researchers are administering Flumist or a placebo to about 10,000 children up to age 17 as part of additional trials required by the FDA, Black said. Only Kaiser members may participate.
Flumist is given to two-thirds of the participants, with the rest receiving a placebo.
So far, about 7,000 children have participated, and the trial is expected to end in mid-December. Children are not routinely given flu shots unless they are chronically ill, but some parents want their children to get them as a precaution.
Angie Yipez, a Head Start teacher from San Jose, took her 6-year-old daughter Angela in for a flu shot in November.
But she decided to have Angela participate in the Flumist trial because, she said, there had been so much previous testing on the vaccine that ``it felt safe.''
``It seemed so much simpler than the shot,'' Yipez said. To Angela, the vaccine felt like cold water that gets in her nose when she's swimming.
``It felt funny,'' Angela said shyly.
IF YOU'RE INTERESTED
For more information about the Flumist trial at Kaiser Permanente, call toll-free (866) 604-1271
Contact Barbara Feder at bfeder@sjmercury.com or (408) 920-5064. |
