Is there a vaccine? For the general public: no.
- The World Health Organization does not recommend vaccination, except for groups at high risk — laboratory staff who are constantly exposed, and health-care workers. Its 2024 manual is blunter: the available plague vaccines have not been proven to prevent plague effectively, they do not protect against primary pneumonic plague, and they may have major side effects.
- In the United States a plague vaccine is no longer available. In the European Union none is approved.
- History: the first plague vaccine was made by Waldemar Haffkine in 1897. A later vaccine made of killed bacteria is no longer used. Live vaccines are still given in some countries; the protection is short-lived and the reactions can be strong.
- New vaccines built on two proteins of the bacterium have passed early clinical trials. None is expected on the market in the immediate future.
So protection against plague rests on three things that do exist: avoiding the routes, early treatment, and preventive antibiotics after an exposure.
What equipment, for whom.
- Ordinary life, with no plague nearby: none.
- Outdoors where plague exists in animals: repellent with DEET; long trousers, socks, closed shoes; clothing treated with permethrin; gloves for handling animals.
- At home with a sick, coughing person while help is on the way: medical masks for the patient and for the one person caring for them; soap and water or an alcohol hand rub.
- Health workers caring for a patient with pneumonic plague: a medical mask, a gown, gloves and eye protection. A respirator of FFP2 or N95 standard is used for procedures that produce aerosols; guidance in the United States notes that it is not necessary for routine care.
- Teams that handle the bodies of people who died of plague: a gown, goggles, an FFP2 or N95 respirator and gloves, as a minimum.
A medical mask or a respirator? Pneumonic plague spreads by droplets at close range. A medical mask worn by the patient stops droplets at the source, and that is the measure that matters most. A respirator filters what its wearer breathes in, and is kept for the higher-risk tasks above. The sealed suit of old photographs is not what today's guidelines ask for.
Hands and surfaces.
- Hands: soap and water, or an alcohol hand rub.
- Clean first, then disinfect. Ordinary household bleach is enough: diluted 1 to 10 for spills of body fluids, 1 to 100 for floors, clothing and bedding.
- Make the solution fresh every day, and leave it on the surface for 10 to 30 minutes.
- Never spray it. Work in a ventilated room, and keep the strong solution off skin and out of eyes.
What does not help.
- A mask against bubonic plague. That route is a flea, and the answer to it is repellent and clothing.
- Antibiotics kept at home "just in case".
- Disinfecting a whole house.
Source. WHO, Plague fact sheet, https://www.who.int/news-room/fact-sheets/detail/plague ; WHO, Manual for plague surveillance, diagnosis, prevention and control (2024), sections 6.5.3 and 7.3 and Annex 9, https://www.who.int/publications/i/item/9789240090422 ; Rosenzweig J. A. et al., "Plague vaccines: new developments in an ongoing search", Frontiers in Immunology 12, 2021, https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.726416/full ; Nelson C. A. et al., MMWR Recommendations and Reports 70(RR-3), 2021, https://www.cdc.gov/mmwr/volumes/70/rr/rr7003a1.htm ; Médecins Sans Frontières, Clinical guidelines: Plague, https://medicalguidelines.msf.org/en/viewport/CG/english/plague-16689935.html
What this is not. Reading, not training in the use of protective equipment and not an infection-control protocol. Health workers follow the protocol of their own service.