Slowing the spread of infectious disease: what is “herd immunity” and why does it matter?

When you are vaccinated against an infectious disease (for example, the flu, or measles) you are not only reducing your own risk of contracting the disease, you are protecting your whole community. Most of us are able to get vaccinated against certain diseases, but for those who are immunocompromised, or otherwise unable to be safely vaccinated, herd immunity is crucial. The concept of herd immunity is simple – most, if not all, of the healthy population gets vaccinated against a disease, making it more difficult for those germs to be spread. This makes it less likely for the community to get the disease.

Herd immunity is most beneficial for those in the community who are unable to be vaccinated, so there is a decreased risk for them to contract the disease. The hope is, over time with more people being vaccinated, the disease becomes so rare that the risk is far less severe, or wiped out totally. This is particularly true for diseases like the measles in the US (until a recent surge in new cases occurred due to anti-vaccination movements). For diseases like the flu, vaccinations and herd immunity are also vital, even though there are many new strains evolving. That’s why it’s especially important to get the flu vaccine every year, to increase the chance of protection from each year’s flu strain.

To better visualize how positively impactful herd immunity can be for the community, check the graphic from the National Institute of Allergy and Infectious Disease below:

As of recently, the biggest talking point in the news about infectious disease is about the coronavirus, or COVID-19. While there is no vaccine available against COVID-19 at the moment, it’s important to keep in mind that we should be making priority to keep our other vaccinations up-to-date. This way, we are not only protecting ourselves and our community from other infectious diseases, we are also taking a burden off our healthcare system and keeping urgent cares and clinics available for those who may have COVID-19. In the meantime, while we wait to see how the response to COVID-19 develops, make sure to follow the advice of health experts such as CDC and WHO (World Health Organization) on how to best protect yourself!

What are your thoughts on this newly emerging infectious outbreak or vaccines/herd immunity? Share in the comments below!