WASHINGTON, DC?Preventing influenza is a challenging task that involves many facets, according to William Schaffner, MD, chair, Department of Preventive Medicine, Vanderbilt University School of Medicine, Nashville, Tenn, and a board member of the National Foundation for Infectious Diseases, who spoke at a recent forum on influenza prevention.
The best way to prevent the rising morbidity and mortality associated with seasonal flu is by increasing overall influenza vaccination rates in the United States, said Cristina Beato, MD, FAAFP, principal deputy assistant secretary of health at the Department of Health and Human Services (HHS). "Achieving these goals is not easy, and it's through partnerships, collaborations, and education, and actual implementation on the ground that this will be achieved."
To cover physicians' expenses for administering the vaccine, the Centers for Medicare & Medicaid Services has increased the Medicare immunization reimbursement from about $8 to $18. In addition, research is continuing on the cell-based culture technology that may one day replace the egg-based production vaccines in use today.
"We also need to understand the domestic capacity production as we encourage the American public to get seasonal influenza vaccines, and I make a special plea for health care providers, who do not have a very proud record of immunization rates....We need to lead by example," Dr Beato said.
Despite the availability of the influenza vaccine, as many as 20% of Americans are diagnosed with the disease each year. Although influenza is more common in children, the highest rates of hospitalization and death are in older adults, beginning at about age 65, according to Ray Strikas, of the HHS National Vaccine Program Office.
Responding to his own question, "What do we want to do with influenza surveillance?" he observes, "We want to know where the viruses are circulating; when they are circulating; the intensity and impact of activity on morbidity/ morality; and the impact of the disease on hospitalization, outpatient visits, and ultimately, death."
A major challenge is trying to measure the disease impact. "The only easy way physicians have of checking for influenza in their offices is what's called the rapid antigen test, but the sensitivity is only about 70% across these different tests," says Dr Strikas. "So they might miss 30% of the cases they actually tested [who] do have influenza."
A virus culture takes up to 3 days, making it unpopular in the practice setting. "It's hard to do influenza virus testing, and you can't test a [finite] percent. Even if the population is sick, you can't test all those people who are coming in for illness," Dr Strikas noted.
New CDC Recommendations
Nicole Smith, PhD, MPH, of the CDC's Advisory Committee on Immunization Practices, discussed some of the key recommendations for 2006-2007:
? Routine vaccination of children aged 24 through 59 months
? Vaccination of household contacts and out-of-home caregivers of children in this vulnerable age-group
? Administering 2 vaccine doses to children in this age-group at the time of initial immunization
? Encouraging physicians to develop plans for expanding outreach and infrastructure to vaccinate more patients than last year, and to develop contingency plans for the timing and prioritization of vaccine administration if the supply is delayed or reduced.
"It is economically and medically problematic to discard unused doses of vaccine."
?Ardis D. Hoven, MD
The CDC is expecting approximately 100 million doses of vaccine to be available for the upcoming influenza season, an increase of about 16% over last year, with the possibility of 15 million to 20 million additional doses if a new vaccine is licensed, says Dr Smith. "Some providers may have limited vaccine for implementing the new recommendations for children...because the prebooking and manufacturing processes were already under way when the recommendations were issued," she warned.
The CDC is suggesting extending the routine vaccination period, since production or distribution delays often result in a critical number of doses not being available until December or even later. Dr Smith said, "To increase vaccination coverage levels, providers should routinely offer vaccines beyond October and November and throughout the influenza season, even after activity has been documented in a community."
The goals of Healthy People 2010 are to vaccinate 90% of individuals aged ≥65 years and all residents of long-term care or nursing home facilities, as well as to vaccinate 60% of other high-risk adults aged 18 through 64 years, Dr Smith said. "We remain short of [these] goals for all target groups," she explained.
"I make a special plea for health care providers, who do not have a very proud record of immunization rates....We need to lead by example." ?Cristina Beato, MD, FAAFP
According to National Health Interview Survey data, only about 65% of those aged ≥65 years, 46% of high-risk adults aged 50 through 64 years, 32% of healthy adults aged 50 to 64 years, 20% of high-risk adults aged 18 to 49 years, 13% of pregnant women, and 42% of health care workers were vaccinated in 2004.
Universal Flu Vaccine
The main reason the flu vaccine supply arrives "almost in time" every year, yet still behind preferred goals, is that "we start every year from scratch," George T. Curlin, MD, MPH, of the National Institutes of Health, remarked. "If you want to talk about the way that research might help expedite the process, it is to eliminate that annual search."
This will require a global effort to embrace the idea of universal vaccination, he explained. "A universal vaccine, getting away from the annual race, would not require an annual change in the vaccine, and it would provide immunity to be ongoing."
The Physician's Role
What is the physician's role in preventing influenza? According to Ardis D. Hoven, MD, of the American Medical Association (AMA), approximately 46% of patients receive their annual influenza vaccination at their doctor's office or a large health care facility.
These health care workers on the front line have a dual role, Dr Hoven said. "Not only are they professionals but also potential patients, and vaccination is a proactive way to protect our patients. We've got to improve patient safety, and that is what the role of the health care provider is all about."
Yet only about 40% of physicians who attended a recent AMA House of Delegates meeting said they had received a flu shot, Dr Hoven noted. "Again, we are not doing a very good job of getting the message out there. How do we get the numbers up? Educate and improve ways for health care workers to get vaccinated and become role models for their patients."
She continued, "We have to utilize all the vaccines available. I queried my hospital pharmacy and asked, ?How many flu shots did you have left over at the end of the season?' And we are not talking about a big metropolitan hospital here, [but] 1000 doses went unused. It is economically and medically problematic to discard unused doses of vaccine."
One of the most important things physicians can do is attempt to change the mindset shared by many patients: If you do not receive the flu vaccine by early December, there is no point in getting it. Dr Hoven stressed that this mindset is also prominent among providers. "By Thanksgiving, everybody sort of backs off and says, ?OK, flu season is over; I am not going to worry about it.' In fact, things are just getting ramped up at that point. Benefits from the flu vaccine remain even when vaccinating through January and beyond."