Knight Ridder Newspapers
WALNUT CREEK, Calif. - As medical experts brace for a flu season with the nation's worst vaccine shortage, the irony of the much-coveted flu shot is that it is least effective in those who need it most.
"It works least well in people who are elderly and don't make antibody as vigorously as they did, or people who have a disease that impairs their ability to make antibody," said Dr. Lawrence Drew, director of the clinical virology laboratory at the University of California, San Francisco.
Seniors stand the greatest risk of developing serious complications from the flu. Out of nearly 36,000 influenza-related deaths in the United States each year, 90 percent are people age 65 and older.
Yet while the flu vaccine can be 70 to 90 percent effective at preventing illness in young, healthy people, the numbers plunge dramatically for seniors.
"When you start to get these frail elderly in nursing homes, it's only about 30 to 40 percent effective in preventing illness," said Dr. Howard Backer, chief of the immunization branch of the California Department of Health Services.
No one questions the wisdom of placing seniors at the front of the line for the scarce shots, however.
The vaccine helps elderly get over the flu quicker and lessens the chance that they will develop other problems.
"That's the goal," said Bill Schaffner, chairman of the department of preventive medicine at Vanderbilt University medical school. "We don't want you to get pneumonia. We don't want you to have to go to the doctor. We don't want you to have to be admitted to the hospital. We certainly don't want you to die of the flu."
The federal Centers for Disease Control and Prevention has estimated that for each 1 million elderly people who are vaccinated with a flu shot, 900 deaths and 1,300 hospitalizations are prevented.
Flu-related deaths have increased substantially during the past three decades. Experts believe this is a result of the aging of the U.S. population.
The older seniors get, the more likely they are to have difficulty recovering from the virus. One study found that people age 75 and older are three to nine times as likely to die from influenza infections as people age 65 to 74.
For people age 85 and older, the risks are even greater.
That is why federal authorities have asked younger, healthy people to forgo shots this year so that those in high-risk groups, including the elderly and people with chronic conditions, can get shots.
Scientists are tracking the flu's progress with great intensity this year as the United States grapples with severe vaccine shortage.
Medical experts remain hopeful the United States will have a mild season, although no one can predict with certainty.
The initial signs are promising:
-New Zealand and Australia, where the flu hits earlier than in the Northern Hemisphere, had a mild season this year.
-The majority of flu viruses identified in the United States thus far have been the A/Fujian strain, a perfect match for this year's vaccine.
-Because A/Fujian was the predominant strain last year, many people who were exposed to it then may still have some immunity.
But there are other factors that give experts pause and could lead to a more severe season.
Near the end of the winter in New Zealand, experts identified an A/Wellington strain, which does not match well with this year's vaccine.
Whether it will gain a foothold in the United States remains to be seen.
"At this point, we don't know what's going to hit our community," said Dr. Roger Baxter, infectious disease specialist for Kaiser Permanente in Northern California. "It's quite remarkable how we just don't know - until it happens."
The national supply shrank by half when vaccine manufacturer Chiron Corp. announced last month that British officials had suspended the license at its Liverpool plant because of contamination problems.
Even predicting when the flu will arrive can be tricky.
"Influenza is fickle," said Bill Schaffner, chairman of the department of preventive medicine at Vanderbilt University Medical School.
"Influenza seasons are usually most active in January, February and into March. But last year, the flu surprised all of us because it came in with a rush and came in early and didn't start on the East coast as it often does, but started down in and around Texas."
Although the flu doesn't typically hit in California until January, last year the state had outbreaks in December. Officials worried whether hospitals could handle the crush during the holidays.
This year, California and 31 other states are now reporting sporadic flu activity, which means a small number of cases.
The state of New York has regional outbreaks, while the flu is widespread in Delaware.
In the San Francisco Bay area, there have been reports of flu at a San Francisco nursing home and a confirmed case in Contra Costa County.
Each year, experts attempt to predict which flu strains will be prevalent the following season and include those in the vaccine-manufacturing process
But as happened last year, strains can change slightly, making the vaccine less than a perfect match and thus less effective. The A/Fujian strain, which became predominant last year, did not align perfectly with last year's vaccine. It has since been included in this year's shot.
Last year, there were reports of severe flu cases and deaths in young children. But Backer said federal authorities did not have adequate statistics to determine whether this was worse than in previous years.
Federal authorities are now recommending that the flu shot be given to children age 6 months to 23 months as part of the routine immunization schedule.
With the interest generated by this year's flu vaccine shortage and concerns about avian flu in other countries, doctors may now be identifying flu cases much quicker than they did in previous years, Schaffner said.
"They're deciding to send specimens to the laboratory that they never would have thought about doing before," he said. "So when you do that, you're going to find stuff that you didn't know about before."
That may make us better prepared, but it also can cause people to fret more about what it all means.
"I don't know exactly when we'll know what kind of a flu season we're going to have. But in the meantime, all of us who have anything to do with flu have our fingers crossed."
Flu outbreaks have hit New York and Delaware, while California and 31 other states report only sporadic influenza activity and 16 states have none.
The flu season typically begins here in January, although last year it kicked off in December. To protect yourself, experts recommend:
- Stay home when sick to avoid contact with co-workers and friends.
- Cover your month and nose with a tissue when coughing or sneezing.
- Wash your hands with soap and warm water or a hand sanitizer. Avoid touching your eyes, nose or mouth.
- Stay healthy by eating nutritious foods, drinking water, exercising, getting plenty of rest and not smoking.
(c) 2004, Contra Costa Times (Walnut Creek, Calif.). Distributed by Knight Ridder/Tribune News Service.