Protecting Others

Community immunity helps protect everyone. When enough people are vaccinated for a pathogen, it makes it difficult for the pathogen to spread. Every person who has immunity makes is more difficult for the pathogen to spread, which is why vaccination is so important for achieving community immunity. If you’re vaccinated, it’ll be harder for the pathogen to use you to infect other people or to mutate into a new variant. The more infectious a pathogen is, the higher numbers of immune people are needed to stop the spread. For example, measles is very infectious. On average every one person infected with measles spreads the virus to 12-18 other people. Therefore, a much higher number of people immune to measles is needed to prevent the spread.  

Community immunity is especially important for those with a weakened immune system that cannot get vaccination for certain disease. This includes people with serious allergies to vaccine components, and people with weakened or failing immunity systems like those who have cancer, HIV/AIDS, or other health conditions.  

Community immunity is one of the reasons we no longer see once feared diseases in the US. Many of the vaccine-preventable diseases that we don’t see often in the US, are spreading in other countries or exist in the environment around us. If not enough people have immunity, such as from lower vaccination rates, we won’t be protected from these diseases. Community immunity only protects us if enough people continue to get vaccinated.