to the editor: This note is in support of the concept of immunizing healthy persons younger than 65 years, as recently recommended by the American Academy of Family Physicians (AAFP), seconded by Zimmerman¹ and endorsed by the accompanying editorial.² To support the case for immunizing the work force as reported by Nichol and colleagues,³ Clover² reiterates the need for a close antigenic match between the vaccine and the attacking strain of influenza, and a high attack rate. However, Clover² seems to minimize the impact of “avoiding lost wages” in contrast to “direct cost savings.” In fact, the payroll costs themselves understate the impact of illness/absence in the workplace as we recently experienced in having to close facilities to new admissions when staffing became inadequate because of laboratory-diagnosed influenza. Most of the staff had chosen not to take the free but voluntary “flu shots.” In production settings, illness-absence can have an even stronger ripple effect.⁴

Other studies have also shown the cost-effectiveness of prophylactic influenza vaccination of persons in the workplace. For example, a randomized, controlled, double-blind study⁵ of 2,079 petrochemical workers in Houston (presented so far only as an abstract) compared the impact of trivalent (influenza types AAB) versus monovalent immunization (influenza type B only) on short-term (one to three days) absence from work. During the moderate influenza A epidemic of 1993 to 1994, the type B-only influenza immunization served as a placebo, and those given the trivalent prophylactic immunization experienced 30 percent less illness/absence. Adverse reactions over two days postimmunization were the same in the two groups (0.5 percent), confirming the low risk of this type of immunization. The evidence of vaccine efficacy was demonstrated in a work force that typically has perfect annual attendance in nearly two thirds of its members; thus, absence may actually understate the impact of illness on productivity. Still others have also found significant (although smaller) benefits from influenza immunization of their workers.⁶

Costs not captured by such studies include the fortunately uncommon but catastrophic cases, in which influenza is complicated by pneumococcal sepsis with multiorgan failure or similar tragic illnesses. From an overall business perspective, the use of influenza immunization makes good sense.

Perhaps if we follow the new recommendation of AAFP's leaders in this regard, we'll raise our own awareness of the more pressing need to protect those of our patients who are at greater risk from influenza and its complications, and come closer to batting a thousand in that department than we currently do. At the same time, we can try to get most of our own health care staff on board, too!

in reply: Dr. Raymond makes excellent points regarding the costs of influenza disease. I agree that some previous studies may have underestimated the costs because of lost productivity and turning away business because of the number of staff who are ill. One possible explanation for the limited number of studies on this topic is that manufacturers in a competitive market might not tell other companies about the benefit of work force vaccination against influenza, thereby maintaining their competitive advantage. The data Dr. Raymond mentions further supports the American Academy of Family Physicians (AAFP) policy, which many other organizations will follow for the fall of 2000—AAFP led the nation on this.

After having lowered the recommended age for annual influenza vaccination to 50 years, what is the next step in reducing influenza morbidity? Data show higher morbidity from influenza in preschool-aged children, particularly within the first two years of life. One possibility is to vaccinate this age group. One technologic advance that might make this feasible is licensure of live attenuated intranasal influenza vaccine that is expected to be available within a few years. Another option is to vaccinate school children because they are among the major transmission routes for influenza within a community.

Experts are beginning to ponder whether to lower the age for pneumococcal polysaccharide vaccination from 65 to 50 years. Smokers and passive smokers appear to be at higher risk for pneumococcal infection. After many years of little to no change in the vaccination schedule for adults, exciting developments are occurring that can lead to reduced morbidity and, for certain vaccines, even reduced costs to society.