Herd Immunity

Black & white sheep tightly packed in a herd on a farm

Herd immunity is something that happens when a large number of people in a community develop immunity (the body’s own protection) against a contagious disease like influenza.  This immunity can be developed naturally when the body makes antibodies after a viral infection that can help fight the infection better the next time.  But importantly herd immunity can also happen through vaccination.

Why is it important?  The idea of herd immunity is based on the thought that, as a community, we can protect our most vulnerable people.  Newborns and people with compromised immune systems are one example.  They either cannot receive vaccines, or they can’t develop immunity to diseases.

For immunosuppressed individuals, their immune systems are weak, which places them at risk.  Even healthy individuals may encounter vaccine failure—an estimated 2-10% of healthy people do not respond to vaccination.

When enough people develop immunity against a disease, however, they can reduce the spread to the people that cannot develop immunity on their own or receive immunisation in the form of vaccines.  In other words, as more people develop immunity, fewer people are sick, and it becomes more difficult for the immunocompromised to come in contact with a sick person.

For this reason, we suggest, even if you don’t tend to get the flu yourself, you can help to protect the rest of the community by getting your flu shot anyway.  Up to 80% of people are asymptomatic carriers of the virus (aren’t aware they are infected), and you wouldn’t know you had passed it on to someone vulnerable.

There is much debate around the world about natural herd immunity of Covid-19.  It is the general opinion in New Zealand that while natural immunity of a community is possible, vaccination-driven immunity reduces illness more effectively.  Call past and talk to a pharmacist today about your flu vaccination.  #heretohelp