ABSTRACT
We describe the Bacillus anthracis protective antigen IgG antibody response and the B. anthracis lethal toxin neutralization activity to a delayed dose of anthrax vaccine adsorbed (AVA, BioThrax(®)) using validated assays. 373 individuals received 1, 2, or 3 priming doses, 18-24 months afterward, they received a delayed dose of AVA. Overall, 23.6% of subjects showed detectable anti-PA IgG before the boost, compared to 99.2% (P<0.0001) 28 days after the boost. Geometric mean anti-PA IgG concentration (GMC) was 1.66 µg/mL before and 887.82 µg/mL after the boost (P<0.0001). The proportion of individuals with four-fold increase in GMC following the boost ranged from 93.8% to 100%. Robust anti-PA IgG levels and B. anthracis lethal toxin neutralization activity are induced when an AVA dose is delayed as long as two years. These data support continuing with the vaccination schedule when a dose is delayed as long as two years rather than restarting the series.
Subject(s)
Anthrax Vaccines/immunology , Anthrax/immunology , Antibodies, Bacterial/immunology , Antibodies, Neutralizing/immunology , Antigens, Bacterial/immunology , Bacterial Toxins/immunology , Adult , Anthrax/prevention & control , Anthrax Vaccines/administration & dosage , Antibody Formation , Enzyme-Linked Immunosorbent Assay , Humans , Immunization Schedule , Immunization, Secondary , Immunoglobulin G/immunology , Male , Middle Aged , Neutralization Tests , Young AdultABSTRACT
The antibody profile during and after the six-dose primary vaccination series with anthrax vaccine adsorbed (AVA, Biothrax) was characterized in 86 human volunteers. Ninety-three percent of recipients developed IgG antibodies to Bacillus anthracis protective antigen (PA) after two doses, and 100% were seropositive after dose #3. Geometric mean concentrations (GMC) of IgG to PA measured before and after each dose were significantly lower after injection #3 (peak GMC=146.65 microg/mL, trough GMC=15.16 microg/mL) than after injections #4 (peak GMC=430.46 microg/mL, trough GMC=94.57 microg/mL), #5 (peak GMC=415.05 microg/mL, trough GMC=81.94 microg/mL), or #6 (peak GMC=401.16 microg/mL, trough GMC=96.19 microg/mL) (pSubject(s)
Anthrax Vaccines/immunology
, Antibodies, Bacterial/blood
, Antigens, Bacterial/immunology
, Bacterial Toxins/immunology
, Adult
, Female
, Humans
, Immunoglobulin G/blood
, Male
, Middle Aged
, Neutralization Tests
, Vaccination
ABSTRACT
A vaccine against Argentine hemorrhagic fever, the "mal de los rastrojos" of the pampas, has been a dream of physicians and scientists involved with the disease since its regognition in the 1950s. Several killed and live immunogens have been produced and tested in pursuit of this goal, none of which has proved suitable for widespread human use. Recently, a new live-attenuated Junin virus vaccine. Candid #1, was developed through a cooperative international effort. Testing conducted to date indicates that this vaccine holds considerable promise
Subject(s)
Hemorrhagic Fever, American , Vaccines , Biological ProductsABSTRACT
A vaccine against Argentine hemorrhagic fever, the "mal de los rastrojos" of the pampas, has been a dream of physicians and scientists involved with the disease since its regognition in the 1950s. Several killed and live immunogens have been produced and tested in pursuit of this goal, none of which has proved suitable for widespread human use. Recently, a new live-attenuated Junin virus vaccine. Candid #1, was developed through a cooperative international effort. Testing conducted to date indicates that this vaccine holds considerable promise
