Ad5-specific neutralizing antibody titers before and after the MRKAd5 HIV-1 gag vaccine regimen.

<p>Serum samples collected at regular intervals during the vaccination schedule from Ad5-seronegative (n = 35, blue dots) and Ad5-seropositive (n = 34, red dots) vaccine recipients were assayed for Ad5 neutralizing antibody activity. Vaccination visits at 0, 4, and 26 weeks are indicated by green arrows. Bars indicate median neutralizing titers for each group at a given time point.