It wouldn’t be the first time you killed a bug with your car

Drive-through flu shots raise eyebrows and sleeves

How do you raise the profile of a potentially life-saving but chronically underused vaccine? Resort to that time-honored marriage of capitalism and the automobile — drive-through service. An infection control professional has done just that, successfully immunizing community members at risk of annual influenza infections while raising the public-service profile of her health care facility.

The idea originally was designed in part to overcome downtown parking problems and address the issue of impaired mobility for the elderly and other targeted populations for flu immunization, explains Ruth Carrico, RN, MA, CIC, director of infection control at the University of Louisville (KY) Hospital. It was also thought that offering a designated drive-through area on the hospital campus might help improve immunizations for people who otherwise would forego the annual vaccine. Indeed, Carrico quickly found the sheer novelty of the approach appealed to people, drawing in even those who dread shots and medical offices.

"They drive up on their own turf,’ she says. "Not that we haven’t chased a few around the car, but by and large it is a totally different experience than giving people a shot in the hospital or in a physician’s office." One of the more unusual sights last year was when a flatbed truck pulled up full of construction workers, at least some of whom thought they were merely on a lunch outing at their boss’ expense. "I said, if this is the first time he’s ever taken you all out, weren’t you suspicious?’" Carrico says. "We had about 18 of them all pile out and get their flu shots and then drive away."

That trend is holding true for other employers as well, as people frequently ask for receipts after driving through and rolling up their sleeves. The high demand for workers in Louisville is no doubt contributing to the situation, as employers are becoming more concerned with productivity lost to illness. "Once you have flu go through like a wave in your office or workplace, you really feel those effects," she says.

Light approach seems to be working

Now entering its fifth season, the program’s popularity appears to be growing annually, she notes. There has been a steady increase in the numbers of Medicare participants as well as requests for information regarding the additional availability of the pneumococcal vaccine. With the aid of volunteer RNs, the program includes a thorough immunization process that includes screening, assessment, patient education, and provisions for post-immunization follow-up if needed, she notes.

Each year, the days and hours of the annual program are advertised to the public, taking a lighthearted approach evidenced by the slogan, "It wouldn’t be the first time you killed a bug with your car," used in newspaper ads. "We are taking an approach so that people are not afraid of immunizations, not just regarding flu but all immunizations," she says. "We have really gotten a whole lot of secondary benefits from it."

That includes increased immunization levels in health care workers, a group historically difficult to vaccinate on a large scale. "It has really helped us increase the awareness in our own staff," Carrico says. "Actually, our immunization rates for our staff are up significantly. We immunize almost 50% of our entire hospital population — obviously [a higher percentage] in the direct health care providers."

Historically, however, flu immunizations have been something of a tough sell to health care workers, who raise doubts about the efficacy of the vaccine and may confuse post-vaccination illness with actual influenza, says James Wilde, MD, a physician in the department of emergency medicine and pediatrics at the Medical College of Georgia in Augusta.

"They didn’t get flu, they got one of the many other respiratory illnesses that can mimic some of the symptoms but are not nearly as severe," he says. "It’s one of the reasons it is difficult to sell, is that people will say they still got sick. Yes, you can still get sick during the winter season, but your chances of getting full-blown influenza are much lower."

Another problem is that the individual immunized every year for 10 years may have actually prevented only one or two cases in himself, because the attack rate for flu is only 10% to 20% during a typical season, Wilde notes. That impact takes on more weight when looking at the overall potential burden to a hospital staffed by susceptible workers. "There is a pretty severe nursing shortage in the country right now, so there are not a lot of extra hands," he tells Hospital Infection Control. "If you have 10% to 20% of your staff out during flu season because they didn’t bother to get vaccinated, your hospital may very well be at a standstill."

Wilde and co-authors published a study earlier this year that found that influenza infection, sick days, and respiratory symptoms were all reduced in health care workers who were immunized.¹ "We hope that the study gives more ammunition to infection control people or administrators who are trying to convince their staff to be vaccinated," he says.

To determine the effectiveness of trivalent influenza vaccine in reducing infection, illness, and absence from work in health care workers, Wilde and co-authors conducted a controlled trial over three years in two large teaching hospitals. Results indicated that 24 of 179 control subjects (13.4%) and 3 of 180 influenza vaccine recipients (1.7%) had serologic evidence of influenza type A or B infection during the study period. Vaccine efficacy against serologically defined infection was 88% for influenza A and 89% for influenza B. Moreover, flu vaccinees had less reported febrile respiratory illness and only 10 days of work absence per 100 subjects, compared to 21 absent days among 100 controls. Another interesting finding was that there were many more days with reported febrile respiratory illness — essentially fever with full-blown flu systems — than there were days absent.

"What that implies is that people were coming to the medical center with full-blown flu, which is very contagious," Wilde says. "They are coming to work with flu and exposing a potentially very vulnerable population. We didn’t look into the medical/legal implications of that, but it would seem to me that would potentially be putting the hospital at [liability] risk."

Indeed, nosocomial influenza infection has been well-documented as a cause of increased hospital days and mortality among patients. Influenza infection in 10% to 20% of a hospital staff per season has major implications for nosocomial transmission, particularly given prolonged shedding of the virus from infected persons and poor vaccine efficacy in vulnerable elderly patients, Wilde and co-authors conclude.

"It’s in the hospital’s best interest to prevent their patients from getting nosocomial infections," he says. "Well, what is a real obvious way to do that? Get your staff vaccinated. Particularly since we know that they are coming to work sick."

Reference

1. Wilde JA, McMillan JA, Serwint J, et al. Effectiveness of influenza vaccine in health care professionals. JAMA 1999; 281:908-913.