FIG. 1.
The study consisted of six animals receiving a live attenuated influenza virus vaccine (A/Texas/36/91; NS1 truncated), four animals receiving a killed influenza virus vaccine (formalin-killed wtTX91), and two animals receiving no vaccine on day 0. Two of the animals that received the live vaccine were sacrificed on day 4. The remainder of the animals were sacrificed on day 25, which was also 4 days after challenge with a 107 50% tissue culture infective dose of wild-type influenza A/Texas/36/91 virus.