Sometimes called blood poisoning by members of the general public, sepsis is the body’s often deadly response to infection or injury. Sepsis kills and disables millions and requires early suspicion and treatment for survival. Sepsis can’t always be prevented once an infection has developed but, by doing our best to prevent infections and treating them if they do occur, we reduce the risk of sepsis.

Sepsis can be caused by any type of infection: bacterial, viral, fungal, or even parasitic. Many infections can be prevented simply by good and consistent hygiene. Others can be prevented through the use of vaccinations.



Viral infections, such as influenza (the flu), chicken pox, and HIV, are caused by viruses. Viruses are microscopic organisms that must live inside a living host, such as humans. Although each virus is different, viruses generally don’t survive for long outside the host.

Usually when you have a viral illness, your body produces antibodies that keep you from getting the illness again – they make you immune. Vaccines have been developed for many viruses, such as chicken pox (Varicella), tetanus, and polio. These vaccines, sometimes called immunizations, trick your body into thinking that it has been infected with the virus – which then makes you immune to actually getting the illness.

Vaccines can be given by injection, by mouth, or intranasally (through the nose), depending on the vaccine.

Some vaccines offer lifetime protection and some need boosters after a certain number of years as the immunity wears off. The influenza vaccine, for the seasonal flu, requires annual vaccinations. The seasonal flu – a respiratory illness that should not be confused with stomach bugs that people may call “stomach flu” – is different every year, so the vaccination you receive one year is not usually effective against the influenza viruses that circulate the following year. You can read more about the flu here in the Sepsis and Influenza section.

Vaccines are necessary for adults, as well as children. To learn which routine vaccines are recommended for North Americans, you can visit the Centers for Disease Control (CDC) or the Public Health Agency Canada. If you are traveling overseas, it is important to check to see if you need additional vaccines to cover illnesses not usually found in North America.