Vaccines are one of the safest and most effective ways we can reduce our risk of suffering from infectious diseases that can make us sick, send us to the hospital, or worse, cause death.

All vaccines work by teaching our immune system to recognize a pathogen – a disease-causing organism. In the case of COVID-19 vaccines, this pathogen is the SARS-CoV-2 virus. When a vaccinated person comes into contact with SARS-CoV-2, their immune system (the body’s defence mechanism) responds by attacking the virus and preventing it from making them sick.

Getting a COVID-19 vaccine helps protect the person who is vaccinated AND helps protect the whole community. The more people who are vaccinated, the lower the individual risk of catching the disease. As COVID-19 vaccination rates increase, infections, hospitalizations, and deaths due to COVID-19 have decreased dramatically in every country that has achieved high vaccination rates.  

When enough people in a population are immune, the risk of the virus causing an outbreak decreases, and we say that the community is protected via herd immunity, or community immunity.

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Why is herd immunity so important?

Herd immunity is crucial, because it helps protect those members of a community who may be unable to be vaccinated or who may not produce a strong immune response after vaccination, due to a specific medical condition, for example.

It is critical that everyone get vaccinated as soon as they are eligible. It is also urgent that everyone across the globe has access to COVID-19 vaccines to protect themselves and their communities. COVID-19 vaccines have already saved lives; ensuring that COVID-19 vaccines are available globally has the potential to save millions more.

But how exactly do COVID-19 vaccines work?

COVID-19 vaccines allow our body to recognize the SARS-CoV-2 virus and to develop the immunity that will protect us from the virus – without getting sick.

There are many different ways to design safe and effective vaccines. Many COVID-19 vaccines contain instructions that teach our immune system how to make and recognize one small piece of the virus – typically the spike protein. After vaccination, our immune system responds by producing antibodies that can recognize the spike protein. In the future, if we are exposed to the virus, the antibodies we developed after vaccination will recognize this virus and stop it from spreading!

COVID-19 vaccines do not cause COVID-19 disease, regardless of the type of vaccine.

What types of COVID-19 vaccines are out there?

Just as there are many different makes and models of cars, there are many different types of COVID-19 vaccines. However, all COVID-19 vaccines are designed to prevent us from getting sick with COVID-19.

It is interesting to learn more about the technologies being used to develop COVID-19 vaccines, including how each vaccine works to strengthen the immune response so it can keep us healthy:

  • DNA- or RNA-based vaccines contain viral genetic material (such as mRNA) which provides the instructions for making a small piece of the virus (viral protein). Then, the immune system learns to recognize that piece.
  • Protein subunit vaccines contain a small piece of the virus (isolated or purified viral protein). Then, the immune system learns to recognize that piece.
  • Non-Replicating viral vector vaccines deliver the instructions (viral genetic material) needed to make a small piece of the virus (viral protein), packaged inside another harmless virus that cannot copy itself. Then, the immune system learns to recognize that piece.

Learn more about how vaccines are rigorously tested  to ensure they are safe and effective, and check out the different types of COVID-19 vaccines that have already been approved.