FIG. 5.

All four monkeys generated anti-poliovirus antibodies after the intranasal inoculations. (A) Anti-poliovirus Western blot. Serum from each monkey was taken at 20 weeks postinfection and used to detect poliovirus antigens (primarily Vp1) by Western blotting. Lanes: U, uninfected cell extract; 1, Polio1-infected-cell extract; 2, Polio2-infected-cell extract. (B) Poliovirus neutralizing antibodies. Serum from each monkey was tested for poliovirus neutralizing antibodies by incubation with 1,000 PFU of Polio1 or Sabin2 (Polio2) (see Materials and Methods). +++, 95% neutralization (with 25 μl of serum); ++, 90% neutralization (with 25 μl of serum); +, 50% neutralization (with 25 μl of serum); +/−, 50% neutralization (with 90 μl of serum); −, no neutralizing antibodies detected (with 90 μl of serum).