Cholera toxin B subunit may not be helpful as adjuvant in pertussis vaccine.

2003 APR 9 - (NewsRx.com & NewsRx.net) -- Cholera toxin B subunit may not be helpful as an adjuvant in an intranasal pertussis toxoid vaccine.

"To investigate the possibility of intranasal immunization with an acellular pertussis vaccine, groups of mice were administered intranasally with aluminum-non-adsorbed pertussis toxoid (PTd; 0.5 or 5 microgram) and formalin-treated filamentous hemagglutinin (fFHA; 5 microgram) with and without recombinant cholera toxin B subunit (rCTB; 10 microgram) as a mucosal adjuvant," researchers in Japan report.

"At a low concentration of PTd, the following things became clear: (1) earlier and higher elevation of serum anti-PTd and anti-FHA IgG antibody titers in the presence of rCTB than in its absence, (2) higher serum anti-PTd and anti-FHA IgG antibody titers than 200 and 100 ELISA EU/mL in all mice, respectively, in the presence of rCTB, which were obtained by calibration against a reference anti-pertussis mouse serum, and (3) in an intranasal challenge experiment with Bordetella pertussis, slightly more rapid elimination of the bacteria from the lungs of mice intranasally immunized in the presence of rCTB, suggesting the effectiveness of rCTB as a mucosal adjuvant," stated Masanori Isaka and colleagues at Nagoya City University Medical School, Chukyo Women's University, the National Institute of Infectious Diseases, and the Chemo-Sero-Therapeutic Research Institute.

The continued, "However, irrespective of rCTB and dose of PTd, mice which were immunized four times and sacrificed on day 35 developed high levels of anti-PTd serum IgG antibodies, high or moderate levels of anti-FHA serum IgG antibodies and mucosal ...