Nat Med: Barrier Immunity Is Expected to Reduce COVID-19 Outbreak Spread

May 16, 2020 /

BioON/--- While attention remains focused on COVID-19 deaths and new cases, another statistic --- the number of people recovering --- may be equally important in achieving the goal of minimizing pandemic infection rates after the lifting of the local admission orderpatients recovering from infection may be immune, i.epresumed immune, which may allow them to safely replace susceptible people in certain high-contact occupations, such as medical personnelFor the expected short-term protection from reinfection--- known as barrier immune --- may allow rehabilitation patients to expand their interaction with infected and susceptible populations, which may reduce overall transmission rates while allowing for expanded interactionimages from NatureMedicine, 2020, doi:10.1038/s41591-020-0895-3new models of this viral behavior suggest that barrier-based intervention strategies may reduce the risk of higher levels of interpersonal communication needed to support the expansion of economic activityThe number of Americans infected with the new coronavirus SARS-CoV-2 may be much higher than officially reported, which could be good news for efforts to protect larger communities using their supposed immunityHowever, there are two important considerations for this strategyThe first is that the duration of immunity to SARS-CoV-2 reinfection remains unknown; however, those who survived the associated virus (such as SARS-CoV) persisted antibodies for about two years, while those who survived merS-CoV infection had about three years of immunityThe second problem is to determine, on a broad scale, who is likely to protect themselves from SARS-CoV-2 infections, which will require reliable serological testing levels, which are not available in the United States"Our model describes how serological tests are used to identify people who have been infected with SARS-CoV and recover from COVID-19, which may help reduce future transmission and promote increased economic engagement," said Joshua Weitz, a professor at the Georgia Institute of Technology's School of Biological Sciences,The idea is to think ahead about how to use the information collected in a new way to identify the recovering person, thereby helping to serve the collective gooda team of researchers from the Georgia Institute of Technology, Princeton University and McMaster recently published a paper in the journal Nature Medicine entitled "Modeling ShieldimmunitytostortCOVID-19spreadin" describing the model behind the concept of barrier immunityBased on the Framework of SEIR (vulnerable-exposed-ininfectious-recovered, susceptibility-exposure-infection-rehabilitation), they studied the potential effects of assumed immunity in rehabilitation patients using a computational model of the epidemiological dynamics of COVID-19, for example, in a population of 10 million inhabitants, the model predicts that, in the worst-case scenario, the implementation of transitional barrier immunization strategies could help reduce the death toll from 71,000 to 58,000, while the enhanced barrier immunization programme could reduce the number of deaths from 71,000 to 20,000The model also suggests that barrier immunization strategies may enhance the effectiveness of social isolation strategies that may still exist after the resumption of higher levels of economic activityscientists have only recently begun to identify individuals with protective antibodies to the new coronavirus The specificity of the antibody test is not 100%, which means that this test may result in false positives However, targeted use of antibody tests in populations with high exposure rates will result in an increase in positive predictions, even if not ethely tested Serological antibody tests differ from the widely used polymerase chain reaction (PCR) test, which is used to determine whether people are currently infected with the virus Among health care providers, serological tests can identify people who recover, who may then interact with patients and reduce concerns about infection Other caregivers may help reduce the risk of transmission in nursing homes, restaurants, emergency medical services, grocery stores, retailing, and other necessary business premises Throughout society, a relatively small number of immune individuals may replace those with unclear immunity conditions, thereby reducing the risk of transmission of recovering individuals and those who are still in the immune initial state "We want to consider serological testing as an intervention," Weitz said Finding out who is immune to the coronavirus may play a significant role in trying to reduce the risk of interacting with people who may be infected with the disease Weitz said serological tests for people who are immune may start with health care providers who are more likely to be infected with the coronavirus because they are exposed to infected people Since many infections do not produce unique COVID-19 symptoms, many people may have recovered from the disease without knowing that they are infected themselves, potentially expanding the number of people recovering "There may be more people who can help reduce communication in their own field and in other specialized areas," Weitz said The reality is that people with high levels of contact may have higher infection rates than other groups "
but the use of antibody information against individuals creates potential privacy concerns that require these people to make informed decisions that accept additional risks for the greater benefit of society." he added, "This model says that if we can identify immune individuals, then it is possible that some individuals do not have to reduce their level of interaction with others because of their lower risk of such interactions." Rather than trying to reduce human interaction (which is helpful, but not good for the economy), we may be able to maintain human interaction while reducing risk "
ultimately, responding to the epidemic will require the development and mass production of a vaccine that can increase immunity levels in the general population by more than 60 per cent Until then, Weitz believes, barrier immunity could be one way to address this challenge he said, "We have no cure." Before we have a vaccine, we will have to use a variety of combinations of strategies to control COVID-19, and barrier immunity may be one of them (biovalleybioon.com) References: 1.Joshua S Weitzetal.
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NatureMedicine, 2020, doi:10.1038/s41591-020-0895-3.
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