Complex Event Analysis - Report
Key Focus
Certainly, we have not seen an immune response related to T cells in overdrive in the very severe cases," said Sette.
Big implications for vaccines
So, assuming that a large portion of the population has some kind of T-cell reactivity to the SARS-CoV-2 virus, what does that mean for vaccine efforts.
There are several implications.
For Dr. Bruce Walker, an infectious disease physician-scientist who spends most of his time doing research in human immunology, it opens the door to a different type of vaccine, similar to the ones that are being used against certain cancers, like melanoma.
"What we know is that most vaccines that have been generated thus far have been based on generating antibodiesDo some people have protection against the coronavirus.
By Dr. Sanjay Gupta and Andrea Kane, CNN.
Updated 6:28 ET, Sun August 2, 2020.
We're now more than seven months into the coronavirus pandemic that has upended the lives of most of Earth's inhabitants. And while it is true that the scientific community has learned many things about the SARS-CoV-2 virus and the disease it causes, Covid-19, there are also many gaps in our understanding.
One big mystery: Why do some people get very sick and even die from their illness, while other similar people show no symptoms and may not realize they've been infected at all.
We know some of the big factors that put people at higher risk of having a severe, even fatal, course of disease: being over 60; being overweight or obese; having one or more chronic diseases such as diabetes, cardiovascular disease, kidney or lung disease, and cancer; and being a person of color -- Black African American, Latino Latinx or Native American.
But might the opposite also be true: Could certain people actually have some type of protection.
A recently published summary article in the journal Nature Reviews Immunology put forth a tantalizing possibility: A large percentage of the population appears to have immune cells that are able to recognize parts of the SARS-CoV-2 virus, and that may possibly be giving them a head start in fighting off an infectionSo, we have been suggesting to anybody that is running vaccine trials to also measure T-cell response," said Sette.
The herd (immunity) grows stronger
There are also implications for when we might achieve "herd immunity" -- meaning that enough of the population is immune to SARS-CoV-2, thanks either to infection or vaccination, and the virus can no longer be as easily transmitted.
"For herd immunity, if indeed we have a very large proportion of the population already being immune in one way or another, through these cellular responses, they can count towards the pool that you need to establish herd immunityThe implications of having some pre-existing immunity suggests that maybe you need a small proportion of the population to be impacted before the epidemic wave dies out," said Dr. John Ioannidis, a professor of medicine and epidemiology and population health at Stanford University.
In other words, if there is a level of herd immunity, that changes how fast the virus ripples through different communities and populations.
In fact, Sette and Crotty wrote in their paper, "It should be noted that if some degree of pre-existing immunity against SARS-CoV-2 exists in the general population, this could also influence epidemiological modelling ..."
Crotty points to a SARS-CoV-2 epidemiology paper that appeared in the journal Science at the end of May that tried to model transmission of the virus going forwardNo momentum supporting factor found
Challenge supporting factors
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