Shortly after the Salk vaccine came into use, a manufacturing error left live virus in one batch.

The Salk vaccine was made from inactivated viruses that could not cause disease.

A few years later the Salk vaccine, which he helped to perfect, provided more lasting protection.

Money was used for epidemic and patient aid, professional education and to finance research, including the Salk vaccine.

Walker will soon be testing the Salk vaccine, and a 2,500-patient trial is already under way.

In addition, those who received the Salk vaccine could pass on the polio virus.

Whereas names like the Salk vaccine are an anomaly.

Lilly manufactured 60 percent of the Salk vaccine in 1955.

Switching to the Salk vaccine may help solve this problem, but carries at least three liabilities.

The Salk vaccine had been available since 1954 but was still new enough that it was not entirely trusted.