The test strains were the same as used in the vaccine except that B/Jilin/20/2003 (a B/Jiangsu-like virus) was utilized for measuring the influenza B responses. of safety is definitely variable and sometimes low [1,2]. One option for improving TIV is to increase vaccine dosage so as to increase serum antibody reactions to the hemagglutinin (HA) as measured in hemagglutination-inhibiting (HAI) and neutralization (neut) checks. Increasing antibody to the HA in serum correlates with increasing protection against illness and illness after exposure to influenza and available information indicates that this antibody is the main mediator of immunity to illness [3,5]. A number of studies have shown that increasing the dose of TIV will Adenosine induce CDC25B an increase in the serum antibody response [6C18]. Dosages as high as 135 g of each HA in TIV (comprising an A/H3N2, A/H1N1 and B computer virus strain) have been shown to be safe in seniors subjects and to induce significantly higher serum antibody reactions as dose was improved [15,17]. In a recent study, we tested the 2000C2001 formulation of licensed trivalent vaccine comprising the standard 15 g of the HA of each component as well as unlicensed concentrations of the same vaccine comprising 30 ug and 60 ug of each HA; the improved dose was well tolerated and induced an increased antibody response . To confirm this finding and to evaluate a high dosage vaccine designed for medical development, a larger number of seniors subjects were given a new 60 g per HA TIV. The gelatin and thimerosal parts in licensed vaccine were removed and only the three viral parts used in 2004C2005 vaccines were increased in concentration; results were compared to the licensed 2004C2005 trivalent vaccine comprising the Adenosine standard 15 g of each HA. 2.0 Materials and Methods 2.1 Study Design This was a multi-site, phase II, randomized, double-blind, stratified study. The primary hypothesis was that the new TIV comprising 60 g of each antigen would be well tolerated and induce a significantly higher serum HAI and neut antibody response than a licensed TIV comprising 15 g of each antigen. The primary endpoints were 1) the proportion of subjects in each group who develop at least a 4-fold increase in antibody titer, 2) the geometric mean titer (GMT) attained by each group and 3) the proportion who attain HAI titers 1:32, 1:64, and 1:128. Secondary endpoints were 1) the rate of recurrence and Adenosine severity of solicited local and systemic reactions, 2) the proportion that were moderate or severe, and 3) the event and nature of unsolicited reactions. 2.2 Subject matter Subjects were 65 years of age or older who have been ambulatory and judged to be medically stable for any underlying illness. Screening and enrollment were carried out during April 2005 at Baylor College of Medicine, The University or college of Iowa Private hospitals and Clinics, St. Louis University or college Health Science Center, Cincinnati Childrens Hospital Medical Center, and the University or college of Maryland School of Medicine. The protocol was examined and authorized by the Institutional Review Boards at each institution before the study was initiated and was carried out in accordance with the 1983 revised Helsinki Declaration. 2.3 Vaccines The licensed sanofi pasteur (sp) 2004C2005 TIV contained 15 g of the HA of A/New Caledonia/20/99 (H1N1), A/Wyoming/03/2003 (H3N2) and B/Jiangsu/10/2003; A/Wyoming is an A/Fujian/411/2002-like strain and B/Jiangsu is definitely a B/Shanghai/311/2002-like computer virus. The experimental vaccine was prepared in a manner similar to standard TIV except that it contained 60 g of the HA of the.