Vaccinia virus (VV) membrane proteins are candidates for orthopoxvirus subunit vaccines and potential targets for therapeutic antibodies. Human antibody responses to these proteins following VV vaccination have not been well characterized.
Pre- and day 26−30 post-vaccination sera from 80 VV vaccine recipients were examined for anti-B5, -A33, -A27, and -L1 specific IgG antibodies by enzyme-linked immunoassay (ELISA). Responses were compared between vaccinia-naïve and previously vaccinated (non-naïve) recipients, and between non-naïve recipients of undiluted and 1:10 diluted vaccine.
VV vaccination elicited anti-A33 (100%) and -A27 (93%) antibodies in nearly all vaccinia-naïve subjects. Pre-existing antibodies were commonly detected in non-naïve subjects (anti-B5, 68%; -A33, 59%; -A27, 38%; -L1, 10%). Anti-B5 antibodies were strongly boosted by undiluted vaccine (geometric mean titer [GMT], 151 vs. 1010, p<0.001, pre- vs. post-vaccination, respectively), while anti-L1 antibody responses were less robust (31% detected, GMT, 75) in non-naïve subjects. Diluted vaccine elicited antibody responses that were similar to undiluted vaccine responses.
Vaccination with VV elicits long-lived specific antibody responses directed against VV membrane proteins that vary by previous vaccination status, but not by 10-fold dilution of vaccine. B5, A33 and A27 should be considered for inclusion in future human orthopoxvirus subunit vaccines.