Poor antibody response after tetanus and pneumococcal vaccination in immunocompromised, HIV‐infected patients
Ten patients with symptomatic HIV infection (six with ARC, four with AIDS) received tetanus and 23‐valent pneutnoeoccal vaccination. Anti‐tetanus IgG and IgM, and anti‐pneumococcal IgG against all 23 capsular types of the vaccine were measured on days 0, 11, 17, 30, and 90. Anti‐pneumococcal IgG were simultaneously determined in two plasma pools of 100 healthy unimmunized blood donors and of 112 healthy adults who had previously received a 14‐valent pneumococcal vaccination. Peak IgG responses to both vaccines were observed on day 17; thereafer, the antibody levels gradually fell again. Anti‐tetanus IgG rose from 0.6 U/ml (geometic mean) to 2.0 U/ml on day 17. Anti‐tetanus IgM remained unchanged, Anti‐paeumococcal IgG increased only by 1.14‐fold compared with pre‐vaccination levels (geometric mean of IgG rises against all 23 polysaccharides in 10 patients), and exceeded the upper 95% limit of unvaccinated blood donors in only 30 out of 230 specimens. Pre‐vaceination levels for pneumococcal type‐specific IgG were significantly higher in HIV‐infected patients compared with the pool of unimmunized healthy controls, possibly indicating a higher rate of previous pneumococcal infections in HIV‐seropositive subjects. However, post‐pneumococcai vaccination levels were significantly tower in HIV‐infected patients than in the pool of healthy controls. The increase in anti‐tetanus IgG significantly correlated with the level of CD4 lymphocytes and with in vitro lymphocyte proliferation by pokeweed mitogen (5 μg/ml) and phytohaemagglutinin (2.5 μg/ml), confirming a particularly low vaccination response in patients who were severely immunocompromied.