wtHBF-1 and rHBF-1 elicited little detectable neutralizing antibody (less than 1:10) against rHBF-1 (Fig. 4E), whereas they had higher levels of neutralizing antibody against the heterologous virus of rHBF-vacH (Fig. 4F), indicating that (i) wtHBF-1 and rHBF-1 caused lethal infection inducing little humoral responses and (ii) the vaccine strain and wild-type CDV shared considerable neutralizing epitopes in their H protein, and F protein can also induce neutralizing antibody production. The gene discussed is MYBPH; the disease is infection.