Pandemic analyst Trevor Bedford of the University of Washington believes that the CCP (Chinese Communist Party) Virus pandemic, or coronavirus, is slowing down in the United States, noting that cases of contagion could be declining as a result of herd immunity.
Through a 16-tweet thread, Bedford laid out what he believes could be a slowing of the CCP Virus pandemic. “I wanted to discuss the degree to which population immunity may be contributing to curbing COVID-19 [CCP Virus] in Florida, Arizona, and Texas, where recent surges have resulted in substantial epidemics,” he wrote.
“After increasing dramatically in June and July, daily case counts in Florida, Arizona, and Texas have begun to subside,” the Bedford added.
According to the Washington Examiner, Texas and Florida, two states considered hot spots because of the high number of infections since early in the summer, have been stabilizing their numbers in recent weeks, with fewer people being tested for the CCP Virus.
On average, Texas was running about 336,255 CCP virus tests per day, representing a 42 percent drop in cases of infection from 62,516 days ago, according to The Texas Tribune.
So far in the United States, there have been more than 5.4 million cases of the CCP Virus, but according to data from the John Hopkins University Coronavirus Resource Center, the actual number may be significantly higher, with more than 160,000 deaths.
However, according to Bedford, people who are vulnerable to the disease in the most affected areas, such as Southern states where there have been high peaks of infection, may develop some form of immunity.
As indicated by Newsweek, Bedford estimated that 20% of Florida’s population, some 4 million people, have been infected with the CCP Virus, although he assures that it may be only 10%.
“Assuming a large majority of infections leave enough immunity to be protected (which I believe to be the case) population immunity of 20 percent will have real impact if societal behavior has already reduced Rt to around 1.2,” Bedford said. Rt is actual transmission rate.
If the actual transmission rate of the virus at any given time is greater than one, then the number of cases will continue to increase, however if it is less than one, this will indicate a significant reduction in the number of infections.
“Even 10 percent population immunity starts to make a difference when Rt is around 1.2,” Bedford added.
According to a study by researchers in Singapore, 23 patients who recovered from SARS in 2003 retained memory T cells of the original pathogen in their systems 17 years later, so scientists are hopeful that the CCP Virus can produce T cells in infected patients that will allow long-term immunity.
In a study published Friday in the journal Science, researchers from Stockholm University in Sweden and Nottingham University in the United Kingdom set out to investigate herd immunity, finding that it could be achieved with a population-wide infection rate of about 40 percent.
According to the article, human populations are far from homogeneous in terms of age and activity levels. So the researchers created a mathematical model to show how such differences might affect the spread of the disease.
They then introduced age differences into the propagation models for the population, finding that the threshold of collective immunity could be reduced by about 40% since “the proportion of infected individuals in groups with the highest contact rates is greater than that in groups with low contact rates,” as reported by Newsweek.
“This shift is because transmission and immunity are concentrated among the most active members of a population, who are often younger and less vulnerable,” the researchers said.
“If non-pharmaceutical interventions are very strict, no herd immunity is achieved, and infections will then resurge if they are eased too quickly,” they added.
Youyang Gu, a computer scientist with the U.S. Centers for Disease Control and Prevention (CDC), attributes some of the declines in infection to social distancing measures in addition to population behavior changes, recognizing that the increase in herd immunity may play a role.
“Immunity may play a significant part in the regions that are declining,” Gu told MIT Technology Review. “I don’t think there is going to be another spike” of infections in Southern states,” he said.