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Herd immunity: Is it the answer to stopping the spread of COVID-19?

What is herd immunity? And will it work against the coronavirus?

PHOENIX — Herd immunity: That is a phrase we have heard and read a lot lately in the debate over the best way to stop the spread of COVID-19.  

Arizona is deep in the coronavirus pandemic if you ask health experts. Over the last few weeks, the number of cases in the Grand Canyon State have exploded.  

Arizonans have been asked by state health officials to physical distance, wear a mask and wash their hands in an effort to stem the tide of the virus.    

However, there are some people that believe that is not the right approach, citing it keeps us from gaining herd immunity. 

But what is herd immunity? And will it work against the coronavirus? 

Deepta Bhattacharya, associate professor of immunobiology at the University of Arizona, explained herd immunity is when a significant portion of a population is exposed to a virus and becomes immune to it.  

“Herd immunity is when enough people have acquired resistance to the infections that transmission is slowed down so that very few new infections are reported as a result, Bhattacharya said.  

Bhattacharya said herd immunity is usually achieved when about 70% of the population gains that resistance.  

“What we are seeing now, even in the hardest of hardest hit spots...only about 20 percent of people have been infected by the virus and show some signs of immunity to it,” Bhattacharya said.

Experts say there are two ways to accomplish herd immunity: With a vaccine or naturally.  

Bhattacharya said scientists are working on vaccines that consists of antibodies that help fight the virus, as well as, vaccines that are made up proteins that allow the human body to make its own antibodies  

The vaccines are basically proteins of the virus. It is not the actual virus but they are proteins of the virus that you are immunized against and so then your own body is making antibodies against those proteins, so if you’re ever exposed to the virus naturally you’ll already have those antibodies that can prevent it from getting into your cells, Bhattacharya explained.  

While a number of companies are racing to develop and test a vaccine, we are still months and perhaps years from a viable cure for COVID-19. And some might be wondering why we did not just try to accomplish herd immunity naturally. 

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Doctors from the Mayo Clinic say herd immunity can be accomplished if a virus is spread throughout a community because people naturally develop antibodies against the virus.  

Scientists say there are some issues with developing herd immunity naturally for COVID-19. 

For one, it is still not clear to researchers if a person who recovered from the virus can maintain immunity.  

Second, research has shown some people have contracted the virus more than once.  

Further research is needed to determine the protective effect of antibodies to the virus in those who have been infected,” according to a Mayo Clinic report 

Nearly 230 million Americans would have to recover from coronavirus in order to accomplish herd immunity naturally and stop the pandemic. 

In May, Johns Hopkins University reported one million people had recovered from the virus worldwide.  

View John Hopkins University data dashboard here. 

Health experts say a push for natural herd immunity could lead to overwhelming the health care system and more people dying.     

“This amount of infection could also lead to serious complications and millions of deaths, especially among older people and those who have chronic conditions,” a Mayor Clinic report explained.  

All eyes were on Sweden early on in the pandemic as the country chose to pursue natural herd immunity. The country of about 10 million people did not enact an official lockdown and kept schools open, according to an NBC report 

Sweden reported 78,504 cases and 5,667 deaths related to COVID-19 as of Thursday. The death rate in Sweden is much higher than that of its Nordic neighbors Finland, Norway and Denmark.   

View the cases and deaths around the world from COVID-19.

Many health experts say the best approach to combating COVID is continuing to physical distance, wear a mask in public and wash your hands regularly.  


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