Prevalence of antibody to current influenza virus strains in adolescents

Abstract

During the Spring of 1986, 118 pupils aged 15-18 years were surveyed for the presence of humoral antibodies to five influenza strains. Prevalence of humoral immunity (HI) antibodies and immunity was found to be related to the year of the strain's emergence and to length of circulation time in the community. A high percentage of the adolescents were not immune to one or more of the tested strains. More than 40% of the studied group were not immune to the old A strains A/Philipines 2/82 (H3N2) and A/Chile 1/83 (H1N1), nearly 70% were not immune to the two B strains (B/USSR 100/83 and B/Ann Arbor 1/86), and almost the entire group (96%) was unprotected against the recent strain A/Singapore 6/86. Only one pupil was immune to all five strains; 35.6%, 22.2%, 17.8%, and 9.2% were immune to one, two, three, or four of the strains, respectively; and 14.4% were not immune to even one strain.

Preliminary characterization of Chlamydia trachomatis hemagglutinins

“…The low hemagglutinating activity of whole EB observed with the majority of RBC species tested was in good agreement with early studies [6,10]. However, the complete hemagglutination of monkey erythrocytes was unusual and previously unreported.…”

“…The hemagglutinin is antigenic and its temperature dependence and heat sensitivity suggest that it is proteinaceous. Similar observations have been made by earlier workers on a hemagglutinin from C. psittaci [6,10]. In contrast, the hemagglutinin present in EB membranes appears tightly bound to the outer membrane, possibly membrane protected and therefore unexposed and non-antigenic.…”

“…Numerous investigators have reported studies on a hemagglutinin from the genus Chlamydia using EB grown in the allantoic cavity of chick embryos [4,6] and L-cells [7,8]. Hemagglutination has been observed with infected host materials [9] and with sonicated EB [8,10]. The latter activity was dependent upon the number of EB in the preparation and was inhibited by specific antiserum [8,10].…”

“…Hemagglutination has been observed with infected host materials [9] and with sonicated EB [8,10]. The latter activity was dependent upon the number of EB in the preparation and was inhibited by specific antiserum [8,10]. Little hemagglutinating activity was associated with RB and partial purification of a hemagglutinin from C. psittaci has revealed a polypeptide composition identical to EB cell walls [8].…”