Recent reports have suggested that the antibody response of elderly persons to standard doses of influenza vaccine is depressed. We examined the effect of an additional threefold dose of influenza B vaccine on the antibody response in elderly, ambulatory veterans. One hundred thirty-one male subjects aged 70 years and older were randomized to receive one of three influenza vaccine regimens: Group I received standard trivalent influenza vaccine containing 15 micrograms of B/USSR/100/83 in one arm and placebo in the other; Group II received standard trivalent vaccine in one arm and a supplemental dose of 45 micrograms of B/USSR in the other; Group III received the same dose as group II combined in one arm with a placebo in the other. Antibody levels were measured at baseline, 1 month, and 5 months. Nearly 80% of the participants achieved levels of antibody to B/USSR considered protective; seroconversion rates varied from 40% to 61%. No significant differences in antibody response to B/USSR occurred among the vaccine groups, and there were more side effects at higher doses. The higher dose groups did, however, achieve greater antibody levels to the drifted influenza B virus which circulated during the year of the study. Response to the influenza A components of the vaccine, however, may have been blunted in Group III which received a large dose of A and B antigens all at one site.

The mechanism responsible for weight stability in adult hamsters was investigated by (a) transecting the dorsoventrally oriented nerve pathways between the septal area and hypothalamus (SH cuts) and (b) partitioning the observed increases in the rate of weight gain into three contributory components: changes in somatic growth, in body fatness, and in energy expended as voluntary activity on horizontal disks. Between 60% and 70% of the weight increase after SH cuts was due to acquisition of lean body mass, and 30%-40% of weight increase consisted of excess body fat. After SH cuts, serum growth hormone and insulin concentrations were increased on Day 14, food intake was increased between Day 2 and Day 42, skeletal lengths were greater on Day 77, and voluntary activity levels were 84% lower on Days 10-45, relative to control hamsters. It is concluded that dorsoventrally oriented nerve pathways in the septal area are involved in the control of growth, maintenance of body fat reserves, and voluntary activity and that they contribute to the maintenance of stable body weight in adult hamsters.Around the time of puberty rodent maintenance of stable weight has commonly weight attains a stable plateau (Monteiro & been labeled a regulation, although its Falconer, 1966; Slob & Van der Werff ten mechanism is not understood. Bosch, 1975;Widdowson & McCance, 1960).The prevailing view is that regulation of This weight level is defended against upward body fat reserves (Kennedy, 1957) accounts (Cohn & Joseph, 1962) or downward (Borer for weight stability in adult mammals and & Kooi, 1975; Levitsky, Faust, & Classman, that any shifts in weight plateau represent 1976) deflections imposed by changes in the shifts in body fat stores (Keesey & Powley, available nutrient energy. Such active 1975). The neural substrate for this weightand fat-regulatory mechanism was initially This research was supported in part by Grants localized in the medial basal area of hypo-RO3M29877 from the National Institute of Mental thalaniUS (MBH), because destruction of Health and PCM78-07626 from the National Science MBH led to increases in body weight, body Foundation to K. T. Borer We thank E S. Valenstein, f t ( Be rnardis & Frohman, 1971; Bernardis N. Radm, and B. Agranoff for the use of some equip-" 01 , -,n^r i-mr-i^ ir>/-«n TT ii_ • j. o ment and facilities, Mara Markovs and Sarah Browne & Skelton , 1965/1966 Hethermgton & for technical assistance, and Neil Rowland for com-RanSOn, 1940), and Serum insulin levels ments that helped improve the manuscript.

The safety and efficacy of current ACIP guidelines for the prevention and control of influenza in nursing home populations are uncertain. An outbreak of influenza A/Sichuan (H3N2) in a teaching nursing home during 1988 gave us the opportunity to evaluate the effectiveness of an influenza vaccination and amantadine prophylaxis protocol. Over 13 days, 12 of 60 residents developed influenza. Prior influenza vaccination had been given to 94% of the residents. Protection from infection occurred in those tested who had antibody levels greater than or equal to 1:16 to the A/Leningrad (H3N2) antigen contained in the standard 1987-88 trivalent vaccine. However, five of 17 vaccinated residents who were tested had antibody levels less than or equal to 1:16 at the start of the outbreak. Amantadine (less than or equal to 100 mg/day) was given to all but one resident starting on the third day of the outbreak, and to employees starting on the sixth day of the outbreaks. Seven residents developed illness after the start of amantadine, although amantadine appeared to ameliorate their symptoms. Although amantadine was generally well tolerated by residents, employees receiving amantadine identified a high incidence of side effects and only 44% of employees took at least 70% of the prescribed amantadine. In our opinion, early detection and protocol-directed intervention probably abated a more severe influenza outbreak. Therefore we support existing recommendations that formal nursing home policies be established to ensure that residents and employees receive annual influenza vaccine and that chemoprophylaxis be used when outbreaks of influenza A are suspected.

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