In every community, there are individuals such as infants, older adults, and organ transplant recipients who rely on the immunity of others to keep them healthy and safe from disease. You may have already come across the term “community immunity.” Community immunity happens only when a large number of individuals in a community are immune to a disease through vaccination and/or prior illness. The most safe and efficient way to achieve community immunity is through vaccination, which is the introduction of a weakened or dead virus or bacteria into the body aimed at priming your immune system without making you ill.
The aim of vaccination is to limit or stop the spread of contagious diseases by reducing the ability of viruses and bacteria to be transmitted from one person to another. The exact number of individuals needed to achieve community immunity varies. Canada’s National Immunization Strategy has established vaccination coverage goals of 95 percent for all childhood vaccines by two and seven years of age. Vaccination coverage of 80 percent is the objective for seasonal influenza and has been established based on the importance of protecting Canadians at high risk for influenza-related complications, hospitalizations, and death.
Community immunity is always important to keep contagious vaccine-preventable diseases under control. During the COVID-19 pandemic, however, reaching immunity that benefits others is more challenging because of new variants, vaccine hesitancy and refusal, and the fact that children under the age of 12 are currently ineligible for vaccination. Despite these challenges, early reports on achieving community immunity against COVID-19 estimated that approximately 70 percent of the population would need to be vaccinated. More recently, estimates have set the goal closer to 80 to 90 percent for vaccinated communities.
Community immunity is still within our grasp. As of August 31, 2021, 67.8 percent of Canada’s population was fully vaccinated. That means we’re well on our way to community immunity. But until we reach our goal, there are individuals in every Canadian community who remain at risk of COVID-19 and need our help to stay protected. We must continue to limit the spread of COVID-19 by encouraging vaccination and following public health measures.