Vaccination: The preventive medicine. Creating immunity and fighting disease.

Vaccination: The preventive medicine. Creating immunity and fighting disease.


Our immune system functions to prevent the infections that cause illness. It protects us from the things that enter our body that don’t belong there, such as disease germs like viruses or bacteria. When viruses or bacteria invade the body, they attack and multiply. This invasion is called an infection. The immune system recognizes these intruders as foreign or ‘non-self’, and produces proteins called antibodies to fight them. Think of antibodies as the soldiers of the immune system.

Immunity memory

The immune system does more than find and destroy these disease germs. It also remembers them. If the same germs enter the body again, the immune system quickly dispatches antibody troops to destroy them before they can make you sick. This is why someone who contracts a disease like measles or chickenpox can be exposed to it many times without catching it again.

However, there is one issue with this system: the first time a person is exposed to a disease, the immune system can’t create antibodies quickly enough to prevent illness. It will eventually fight off the infection, and provide future immunity from the same disease. But it doesn’t prevent the disease the first time. The danger with that is that some illnesses can have profound complications and may even be fatal, so vaccination becomes a crucial way of prevention.

Vaccination as prevention

Vaccination is a crucial means of disease prevention by which an individual can develop immunity without getting sick first. Vaccines contain the same germs that cause disease. But the disease germs in the vaccine have either been killed, are only a part of the disease germ, or are weakened to the point that they cannot cause illness.

Vaccines help develop immunity by imitating an infection. When an individual is vaccinated, the vaccine stimulates the immune system to produce antibody troops, exactly as it would if it were exposed to the disease. But the ‘imitation infection’ does not cause illness. It may cause minor symptoms, such as fever, but this is normal, and should be expected as the body builds immunity.

A powerful medicine

Vaccines are extremely efficient in the fight against infection. Most vaccines produce immunity around 90 -100% of the time. A good example is the human papilloma virus vaccine which has an efficacy rate of 96.7%.

Human papilloma virus (HPV) is one of the most common sexually transmitted infections. Three out of four sexually active people will get HPV at some point in their lives. Most carriers show no signs or symptoms and can pass the virus on to others without knowing it. Most HPV infections will clear on their own, but for some, the cells infected with the virus can become cancerous over time.

Each year in Canada, approximately:

  • 1,400 women will get cervical cancer & 400 will die from the disease
  • 229,000 women will develop precancerous changes to the cervix
  • 436 women will get vulvar or vaginal cancer & 128 will die from the disease
  • 36,000 people will develop genital warts

The great news is that we have excellent vaccines that provide very good protection against HPV. Gardasil 9 is the newest vaccine against HPV and it provides protection against 9 different types of the virus (while previous vaccines covered 2 or 4 types only). Gardasil 9 protects against approximately 90% of cervical cancers and 90% of genital warts.

The HPV vaccine is recommended for:

  • Females 9 to 45 years of age
  • Males 9 to 26 years of age
  • Males 27 years of age and older who have sex with males

Unlike women, men rarely develop antibodies to natural infection, at least not at a high enough level to provide protection. So young men should consider having vaccines that stimulates rigorous antibody production.

One still needs to keep in mind that because even the new vaccine does not protect against 100% of cancers, paps will still be necessary.

Most medicines treat or cure diseases. Vaccines actually prevent them. This is what makes vaccination such a powerful medicine in the fight against disease.