Bubonic Plague vaccine

Your report “The Plague Returns” [ FT361:11] from

The Economist states that no vaccine has been developed for Bubonic Plague. Not so. I was a lab technician at Cutter Labs in Berkeley, California, in 1968. One of my jobs was testing plague vaccine. The bacteria were killed with formaldehyde and we tested for the concentration of this chemical. We mouth pipetted samples because the lab wanted us to work as quickly as possible. If you overshot, you got a mouthful of vaccine, and if the level of formaldehyde was too low it meant you had live bacteria as well. Naturally, we were immunised every six months and I never overshot because formaldehyde isn’t good for you either. Plague vaccine was developed in 1890 and has been improved over the years. Governments keep a supply in case of emergencies because the disease is endemic in parts of the world. It also would make an excellent germ warfare agent if their attention faltered. Nancy Farmer Portal, Arizona