Nicholas A., an associate of the Harvard Modeling Lab. Menzies said that each model has “warts” because they use somewhat different assumptions about lethality rates and test accuracy. But all come to the same conclusion: Although parts of the country were heavily infected in the spring – more than 20 percent of the residents of the New York metropolitan area are considered immune, for example – the nationwide average is much lower.
More than 200,000 Americans have already died, and models estimate that if people return to old habits, such as gathering indoors without a mask, more than 300,000 and possibly 400,000 may die before one Vaccine should be widely available.
The main proponents of the idea that herd immunity is somehow closer are American and European medical professionals who oppose the lockdown. He says that most people in the world are immune to viruses, which are caused by “T-cell immunity” from those common centers caused by four relatively benign coronaviruses that have been circulating for years. .
But this theory is unfounded. Helper T-cells are white blood cells that, once “primed” by initial infection, can lapse into tissues for decades until they are reunited with the same virus and destroy it, By triggering the production of antibodies and summoning other virus-killers. .
(Shane Crotte, a virologist at the La Jolla Institute for Immunology, offered the metaphor of a Lego car. Antibodies recognize the car’s morphology and disable it. But T-cells individual Lego blocks, even the inner ones. Too. For example, having already been parked inside a human airway cell, the primary helper can effectively move part of the car to attract the attention of T-cells, which are toxic proteins. Can recruit “killer T-cells” to take them out. Both garage and car.)
The immunity given by a common cold coronavirus lasts for a year or two, immunologists say, and then a person can catch the same cold again. Antibodies against it go away; Primitive T-cells remain.
Dr. Kratty said that T-cells can reduce the odds of dying from new, dangerous coronaviruses, but this has not been proven. There is no evidence that they prevent infection from it.