What tissue from infected rabbits did Pasteur use to prepare rabies vaccine?

Pasteur used the spinal cord of infected rabbits to prepare the first rabies vaccine. His team grew the rabies virus in rabbits and then weakened the infected nerve tissue by drying it for progressively longer periods.

The method was based on the observation that rabies primarily affects nervous tissue. The dried spinal cords contained virus with reduced virulence, allowing Pasteur to give patients a series of inoculations that gradually increased in strength.

The best-known recipient was nine-year-old Joseph Meister, bitten repeatedly by a rabid dog in July 1885. He received 13 injections over 11 days and survived. Émile Roux was a key collaborator in developing the technique.

A common mix-up is to call this a modern vaccine. Today’s rabies vaccines are made with purified, inactivated virus grown in cell cultures, not infected animal spinal cords.