All About Vaccines
June 24, 2020

There is a lot of discussion about vaccines right now and if one will be developed for the COVID-19 virus. So this is a great time to discuss how vaccines work and their safety. When the body develops an infection from a bacteria or virus, our immune systems use white blood cells to stop the attack. We will discuss the 3 main white blood cells that are released:

  1. Macrophages – swallow and digest germs, as well as dead or dying cells. Macrophages leave behind parts of the germ known as antigens. The body identifies antigens as a danger and stimulates antibodies to attack.
  2. B-lymphocytes – produce antibodies to attack antigens
  3. T-lymphocyctes – attacks cells in the body that have been infected.

The first time the body is infected, it takes a few days for the immune system to make the necessary cells and defend the body. After that first infection, the immune system remembers how to protect the body. A few T-lymphocytes (also known as memory cells) remain so the body can create a quick defense next time. When familiar antigens are found, the B-lymphocytes produce antibodies to attack them.

Vaccines trick the body into thinking that the body has an infection. The immune system creates T-lymphocytes and antibodies. This is why minor symptoms, such as a fever, can occur after receiving a vaccine and should be expected as the body builds immunity. After the “imitation” infection resolves, the body is still producing B-lymphocytes and T-lymphocytes. This can take a few weeks, so it is possible to still
develop the disease if you come into contact with it.

There are many different ways to develop a vaccine. The approach is based on the infections the vaccine will prevent (virus or bacteria), how the germ infects the cell, how the immune system responds to it, as well as environmental factors (such as where the disease is in the world). The different types of vaccines will be discussed in a future newsletter.


Yes! Vaccines are made from weakened or dead germs, proteins or complex sugars called polysaccharides. Vaccines must pass many safety tests before they are approved. Newly developed vaccines are given to a small number of people to test for dose and safety. They are then given to hundreds or thousands to study safety of the vaccine. After approval for general use, each lot (or batch) is tested and approved by Health Canada before it is used. Any adverse effects are reported and tracked by Health Canada. Every serious event is reviewed in detail.


Your body comes into contact with millions of germs per day! Vaccines introduce only a small amount of the bacteria or virus. Administering more than 1 vaccine at a time is not a problem as our immune systems are used to dealing with
many more germs at a time.


Shringix is the newest vaccine to protect against varicella zoster, also more commonly known as the shingles virus. This is the same virus that causes chicken pox. After we recover from chicken pox, the virus remains in our body and can reactivate in the form of shingles. Shingles usually begins with flu like symptoms that develops into a painful, blistering rash that may last several weeks. For some, a serious complication called postherpetic neuralgia may occur, resulting in long lasting nerve pain.

The risk of shingles increases as we age and our immune response lowers. One of the best ways to protect yourself against shingles after the age of 50 is through vaccination. Shingrix is a non-live vaccine that has been studied in over 29,000 people. It is given as a two dose series, with the second dose given two to six months after the first. This vaccine has shown to be over 90% effective and remain effective for over four years. The vaccine is well received with the most common side effects being pain, redness and swelling at the injection site, as well as flu like symptoms. If you would like more information on
Shingrix, feel free to discuss this vaccine with one of our pharmacists today.