When discussing vaccination, we usually think about vaccines administered to children. And yet, vaccination shouldn’t stop with the last shot given in high school. Some vaccines must be repeated regularly, while others are only given in adulthood.
Childhood vaccines that must be repeated in adulthood
As of the age of six months, all Canadians should get a flu shot every year, not only to protect themselves, but also to protect others around them who may be vulnerable, such as babies too young to get the flu shot, or persons with a compromised immune system due to illness or medical treatment (e.g. cancer, transplant).
A new vaccine is produced every year. Since producing the vaccine takes several months, developers base its formula on the most common flu strains in the period immediately preceding the vaccine production. However, the most common active strains can change in the following months, and the vaccine is therefore less effective. Despite this possibility, it is best to get vaccinated every year.
The vaccine against diphtheria and tetanus should be renewed every 10 years. Diphtheria is caused by a bacterium that is transmitted from one person to another through respiratory tract secretions. It causes a sore throat and difficulty swallowing. Left untreated, it can lead to serious and respiratory problems and can even be fatal. Diphtheria is very rare in Canada, but it is still widespread in developing countries, where most people are not vaccinated.
Tetanus is caused by a bacterium that can be found in the soil all over the planet. The infection usually develops after dirt or organic matter gets into an open wound. It causes muscle spasms that usually begin in the jaw and gradually spread to other muscles. Left untreated, it can be fatal. Tetanus is not contagious.
Vaccines administered in adulthood only
Zona is a disease caused by the virus that causes chickenpox. After someone has had chickenpox, the virus stays in the body and may get reactivated several decades later. The risk of developing zona increases greatly after the age of 50, although it can manifest before then. Zona causes a very painful rash that can lead to serious complications, such as persistent pain even after the rash is gone, or blindness if the eye is affected. It is recommended that all adults over the age of 50 get the zona vaccine.
Pneumococcal infections are caused by a bacterium that can cause infections in the lungs, brain or blood. Each year, some 3,000 Canadians are hospitalized due to a pneumococcal infection. There are two types of vaccines against this bacterium. The “conjugated” vaccine is given as part of the vaccination schedule in childhood. The polysaccharide vaccine, however, is recommended for all adults as of the age of 65, anyone living in a long-term care facility (regardless of age), and certain adults with a chronic illness that puts them at greater risk of complications if they get a pneumococcal infection.
Other vaccines that can be administered in adulthood
The chickenpox vaccine is relatively new. It is now given as part of the vaccination schedule for children. If adults between the ages of 18 and 49 think they have never had chickenpox, a test is usually performed to see whether they are immune, because most Canadian adults have had chicken pox, they just don’t remember it. If they don’t have any chickenpox antibodies, it is then recommended that they get the vaccine, because adults are at greater risk of severe complications if they contract the disease. The vaccine is not recommended for individuals over the age of 50, because they are considered immune.
Human papilloma virus (HPV)
The HPV vaccine is also relatively new and is part of the regular vaccination schedule. The vaccine protects against the virus strains associated with the most serious complications, especially cervical cancer.
If it wasn’t given as part of the regular schedule, the HPV vaccine is recommended for all sexually active women under the age of 27, as the virus is transmitted during sexual contact, typically about 5 to 10 years after the first sexual experience. It is also recommended in women aged 27 and over who are at a continued risk of HPV exposure, since certain studies have found that there is a recrudescence in HPV cases in women aged 45 and over. The vaccine is also approved for boys and men under the age of 27, in order to reduce the transmission of the virus to women.