Herd Immunity: When will we achieve it?

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Posted at 6:00 AM, Feb 25, 2021
and last updated 2021-02-25 09:05:25-05

TUCSON, Ariz. (KGUN) — When a contagious disease enters a group, most people get sick because our bodies don’t have the immunity to fight off that foreign invader. But that’s where herd immunity comes in.

"Herd immunity basically refers to the number of people in a population that need to be immune to a specific infectious disease in order to keep it from spreading through the population," says Dr. Clifford Martin, Infectious Disease Specialist, Tucson Medical Center.

And it all comes down to epidemiology and statistics.

"There is a different threshold for human herd immunity for a disease that is different for every different type of virus or every different type of contagious disease," says Martin.

Take COVID-19 for example…

"The predictive models estimate that about 70% of the people need to have immunity in order to achieve that threshold to keep it spreading effectively," says Martin.

So how long before we get to that 70%? Doctors say...

"As long as the supply chain continues to go, as long as the pharmaceutical companies continue to manufacture it, I think that my best guess would be by the end of the year we'll be pretty close," says Martin.

Doctors say because we live in an instant-gratification kind of society, it’s easy to lose sight of the fact that the COVID-19 vaccine development and rollout is happening quite quickly. So bear with it, wear the mask and keep doing your best to make decisions that will help us achieve that 70% herd immunity we’re all waiting for.