The first three months of the COVID-19 epidemic: Epidemiological evidence for two separate strains of SARS-CoV-2 viruses spreading and implications for prevention strategies

Abstract

About one month after the COVID-19 epidemic peaked in Mainland China and SARS-CoV-2 migrated to Europe and then the U.S., the epidemiological data begin to provide important insights into the risks associated with the disease and the effectiveness of intervention strategies such as travel restrictions and lockdowns ("social distancing"). Respiratory diseases, including the 2003 SARS epidemic, remain only about two months in any given population, although peak incidence and lethality can vary. The epidemiological data suggest that at least two strains of the 2020 SARS-CoV-2 virus have evolved during its migration from Mainland China to Europe. South Korea, Iran, Italy, and Italy's neighbors were hit by the more dangerous "SKII" variant. While the epidemic in continental Asia is about to end, and in Europe about to level off, the more recent epidemic in the younger US population is still increasing, albeit not exponentially anymore. The peak level will likely depend on which of the strains has entered the U.S. first. The same models that help us to understand the epidemic also help us to choose prevention strategies. Containment of high-risk people, like the elderly, and reducing disease severity, either by vaccination or by early treatment of complications, is the best strategy against a respiratory virus disease. Lockdowns can be effective during the month following the peak incidence in infections, when the exponential increase of cases ends. Earlier containment of low-risk people merely prolongs the time the virus needs to circulate until the incidence is high enough to initiate "herd immunity". Later containment is not helpful, unless to prevent a rebound if containment started too early.

Population-level COVID-19 mortality risk for non-elderly individuals overall and for non-elderly individuals without underlying diseases in pandemic epicenters

“…It is argued that lockdowns may be even harmful as a response to COVID-19 itself, if they broaden rather than flatten the epidemic curve. 56 Information from seroprevalence and universal screening studies suggest that the frequency of infections is much larger than the documented cases and thus the overall infection fatality rate is much lower than previously thought. 57–59 It seems that the vast majority of infections are either asymptomatic or mildly symptomatic and thus do not come to medical attention.…”

“…29 It is even argued that lockdowns may be even harmful as a response to COVID-19 itself, if they broaden rather than flatten the epidemic curve. 30 Information from large scale testing and seroprevalence studies should soon give us a more clear picture about the true frequency of infections and thus more accurate assessments of the overall infection fatality rate. Data from Iceland suggest that almost all infections are either asymptomatic or mildly symptomatic and thus do not come to medical attention.…”

HRNET: AI-on-Edge for Mask Detection and Social Distancing Calculation

“…Further, the discussion and studies done by Wittkowski [14] and Kissler et al [15], state that effectiveness on lockdown strategy is not known to impact the spread of the virus. Industries, such as hospitality, the airline, have taken a significant hit, followed by agriculture taking a global drop of more than 20% in demand, and manufacturing had shown a large drop in overall demand [16].…”

Spatiotemporal Analysis of COVID-19 Incidence Data

“…A new coronavirus, causing a severe acute respiratory syndrome (COVID- 19), and being transmitted between individuals, was originally identified as 2019nCoV in Wuhan (China) in December 2019 and subsequently named SARS-CoV-2 for its 80% genome homology to that of the HCoV SARS (SARS-CoV-1) and the resemblance of its clinical manifestations to those of the aforementioned virus [1][2][3]. The epidemic was rapidly spreading from China throughout the world, to become a pandemic that, as of today, has affected more than 118 million people, causing over 2.6 million deaths [4,5]. During the first phase of massive campaign of vaccination to prevent SARS-CoV-2 infection and the related disease COVID-19, we still need to use the common measures to attempt containing pandemic such as facial masks and disinfectants, avoiding people gathering and social distancing, massive testing and tracing, or more severe restrictions like quarantine, curfew or lockdowns of all near-contact activities.…”