Vaccine Antibody Titers Research Articles

Enhancement of passive immunity with maternal vaccine against newborn calf diarrhea.

The effects of a maternal vaccine against newborn calf diarrhea associated with group A bovine rotavirus (BRV), bovine coronavirus (BCV), bovine parvovirus and K99 Escherichia coli (E. coli) were examined on a beef cow-calf herd. After vaccination, serum or colostrum antibody titers to BRV, BCV and E. coli K99 in the vaccinated cows were significantly higher than those in unvaccinated control cows. Serum antibody titers to BRV, BCV and E. coli K99 in calves from the vaccinated cows were also significantly higher than those in calves from the control cows for 3-4 weeks after birth. These results suggested that the immunization of cows with the maternal vaccine enhanced the passive immunity levels in calves against BRV, BCV and K99 E. coli.

Effect of Age on Cytotoxic T Lymphocyte Memory as well as Serum and Local Antibody Responses Elicited by Inactivated Influenza Virus Vaccine

Healthy seropositive adults aged < 40 (n = 15), 40-64 (n = 15), and > or = 65 (n = 17) years were parenterally immunized with trivalent subvirion influenza virus vaccine, and their cellular and humoral immune responses were compared. Vaccination resulted in a significant enhancement of class I human leukocyte antigen-restricted influenza A cross-reactive cytotoxic T lymphocyte (CTL) memory. Elderly subjects had significantly lower baseline and peak postvaccination mean percentages of specific lysis of influenza A virus-infected autologous targets but nonetheless mounted CTL responses to vaccine that were comparable in magnitude to those of younger adults. Serologic responses and nasal IgG responses to each of 3 vaccine strains were reduced in magnitude and frequency with advancing age. Parenteral immunization was ineffective at inducing nasal wash IgA antibodies. Between 2 and 12 weeks after vaccination, serum and nasal antibody titers decreased modestly, although the rate of decline was comparable between age groups. The ability of elderly adults to mount CTL responses after influenza vaccination suggests that T cell effector mechanisms may be an important determinant of vaccine-induced protection against serious illness in this age group.

Duration of the immune response in subjects inoculated with antimeningococcal A and C vaccines kept in storage at -20 degrees C and at 4 degrees C: influence of pre-vaccination titres on the vaccinal response.

The antibody titres in 250 subjects, aged 5 to 22 years, who were vaccinated with a mannitol-lyophilized antimeningococcal A + C vaccine, stable only when stored at -20 degrees C, were followed for two years. As measured by indirect haemagglutination (IHA) and indirect immunofluorescence (IF) techniques, titres for both A and C Neisseria meningitidis antibodies remained high. Two years after vaccination titres of antibodies against type A showed fourfold increase over the initial titres in from 46% to 100% of groups of subjects and against type C in from 42% to 80%. For 130 subjects vaccinated with a new lactose-lyophilized antimeningcoccal A + C vaccine (presumed stable at 4 degrees C) antibody titres were measured up to 16 months after inoculation with this vaccine stored at -20 degrees C and also after storage for several periods at 4 degrees C. Antibody titres in all these subjects had fallen to their initial titres by 16 months. The importance of evaluating the results on subjects showing low initial titres (less than or equal to 1/8 as measured by IHA) is discussed, as inclusion of high initial titres influences the extent of the response.

Efficacy of Formalin Killed Fowl Cholera Vaccine in Experimentally Immunized Fayoumi Chickens

Efficacy of experimentally prepared formalin killed fowl cholera vaccine in Fayoumi chickens via different routes of vaccination was determined during the period from April 2002 to March 2003. Pasteurella multocida (PM-38) serotype 1 (X-73) was employed for vaccine preparation and antibody titres of the chicken sera were determined by passive haemagglutination (PHA) test. Vaccination was done either intramuscularly or subcutaneously. Each of the experimental chickens was challenged with a virulent isolate of P. multocida @ 3.8 x 108 CFU / ml per bird intramuscularly. The 100% vaccinated chickens protected against virulent P. multocida infection but all (100%) unvaccinated control birds died within 72 hours of challenge. Intramuscular (both primary and booster) route of vaccinations was found superior and more effective than subcutaneous route of inoculation. The higher PHA antibody titre was recorded with intramuscularly (222.86 ± 25.60) than subcutaneously (111.43 ± 12.80) vaccinated groups of birds. The result revealed the fact that intramuscular route followed by subcutaneous inoculation could be done for immunization against fowl cholera in chickens. Key words: Efficacy; fowl cholera vaccine; formalin killed; Fayoumi chicken doi: 10.3329/bjvm.v2i1.1929 Bangl. J. Vet. Med. (2004). 2 (1) : 23-25