Close to Herd Immunity? New Study Finds Common Cold May Provide Coronavirus Immunity

A new peer-reviewed study out of Singapore, published in the Nature Research Journal, has hopeful news regarding the coronavirus pandemic. The study revealed that the common cold may provide some level of immunity to the novel coronavirus. This also may indicate that we are much closer to herd immunity than has been reported.

There are hundreds of millions of cases of the common cold every year, according to the Centers for Disease Control and Prevention (CDC). Coronaviruses account for 15% to 30% of all “common colds” contracted annually.

The scientists who conducted the study, which has been peer-reviewed, examined whether T cell responses to other coronaviruses carried over to the virus that causes COVID-19, SARS-CoV-2.

According to Genscript, memory T cells play a vital role in protecting the body from pathogens. These cells “have been trained to recognize specific antigens, [and] they will trigger a faster and stronger immune response after encountering the same antigen.”

The scientists studied 23 people who had been infected with SARS-CoV from the 2003 SARS outbreak. They found that 17 years later, all those infected and examined still possessed “long-lasting memory T cells” that recognized and reacted to a specific structural protein called SARS-NP.

This is great news. There has been rising concern that those infected with COVID-19 may be able to get the disease again due to speculation that the antibodies produced after infection with COVID-19 potentially only last for a few months.

However, this study gives hope that even if the antibodies dissipate relatively quickly, the memory T cells may remain for far longer.

The study provided even more good news by revealing that the memory T cells, which had been created to respond to SARS-NP, “displayed robust cross-reactivity to SARS-CoV-2 NP.”

In other words, the memory T cells from those who contracted SARS-CoV during the 2003 outbreak also recognized and responded to the novel strain of the coronavirus, SARS-CoV-2 (COVID-19). The 2003 outbreak consisted of a different strain of coronavirus that infected at least 8,000 people worldwide.

Since very few people were originally infected with SARS-CoV, the scientists then examined whether memory T cells produced in response to other coronaviruses, like the 15% to 30% of annual common colds, would respond to SARS-CoV-2.

They tested 37 people who had been unexposed to COVID-19 and found that 19 of the 37 unexposed individuals with memory T cells for other coronaviruses responded to SARS-CoV-2.

A similar study out of Germany found an even better result with 81% of those tested showing some level of immunity to SARS-CoV-2 due to preexisting memory T cells produced from common colds.

According to Daniel Horowitz, an author at Conservative Review, “the study provides new evidence for the theory that herd immunity could be achieved at an approximately 20% infection rate for most cities, thanks to T cell cross-immunity from other coronaviruses.”

It’s been widely reported that the United States may need to see a 70% infection rate with COVID-19 in order to reach herd immunity.

If, however, like the Singapore study suggests, around 50% of those who have had a different coronavirus in the past have some level of immunity to SARS-CoV-2, then if an additional 10% to 20% of people become infected with COVID-19, that 70% level herd immunity threshold could be quickly reached.

Gabriela Gomes, a professor at the University of Strathclyde, in Glasgow, Scotland, told The Atlantic that she also suspects the threshold for herd immunity to be at or less than 20%. “We just keep running the models, and it keeps coming back at less than 20 percent. It’s very striking,” she said.

As several antibody tests have revealed, the true number of positive coronavirus cases could be up to 10 times higher than the official tally. CDC Director Robert Redfield confirmed this suspicion in June based on antibody tests.

The United States has currently had 3,830,000 confirmed cases of COVID-19.

If the number of people that have had COVID-19 is 10 times the official tally, that means that up to 38,300,000 have had COVID-19, which is 11.67% of the total population of the United States.

In other words, if T cell research and mathematical modeling align, we could be on the verge of obtaining herd immunity to the novel coronavirus.

You can follow this author on Twitter @MettlerZachary

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