Reinfection with SARS-CoV-2: Discrete SIR (Susceptible, Infected, Recovered) Modeling Using Empirical Infection Data (Preprint)

2020 ◽  
Author(s):  
Andrew McMahon ◽  
Nicole C Robb

BACKGROUND The novel coronavirus SARS-CoV-2, which causes the COVID-19 disease, has resulted in a global pandemic. Since its emergence in December 2019, the virus has infected millions of people, caused the deaths of hundreds of thousands, and resulted in incalculable social and economic damage. Understanding the infectivity and transmission dynamics of the virus is essential to determine how best to reduce mortality while ensuring minimal social restrictions on the lives of the general population. Anecdotal evidence is available, but detailed studies have not yet revealed whether infection with the virus results in immunity. OBJECTIVE The objective of this study was to use mathematical modeling to investigate the reinfection frequency of COVID-19. METHODS We have used the SIR (Susceptible, Infected, Recovered) framework and random processing based on empirical SARS-CoV-2 infection and fatality data from different regions to calculate the number of reinfections that would be expected to occur if no immunity to the disease occurred. RESULTS Our model predicts that cases of reinfection should have been observed by now if primary SARS-CoV-2 infection did not protect individuals from subsequent exposure in the short term; however, no such cases have been documented. CONCLUSIONS This work concludes that infection with SARS-CoV-2 provides short-term immunity to reinfection and therefore offers useful insight for serological testing strategies, lockdown easing, and vaccine development.

10.2196/21168 ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. e21168
Author(s):  
Andrew McMahon ◽  
Nicole C Robb

Background The novel coronavirus SARS-CoV-2, which causes the COVID-19 disease, has resulted in a global pandemic. Since its emergence in December 2019, the virus has infected millions of people, caused the deaths of hundreds of thousands, and resulted in incalculable social and economic damage. Understanding the infectivity and transmission dynamics of the virus is essential to determine how best to reduce mortality while ensuring minimal social restrictions on the lives of the general population. Anecdotal evidence is available, but detailed studies have not yet revealed whether infection with the virus results in immunity. Objective The objective of this study was to use mathematical modeling to investigate the reinfection frequency of COVID-19. Methods We have used the SIR (Susceptible, Infected, Recovered) framework and random processing based on empirical SARS-CoV-2 infection and fatality data from different regions to calculate the number of reinfections that would be expected to occur if no immunity to the disease occurred. Results Our model predicts that cases of reinfection should have been observed by now if primary SARS-CoV-2 infection did not protect individuals from subsequent exposure in the short term; however, no such cases have been documented. Conclusions This work concludes that infection with SARS-CoV-2 provides short-term immunity to reinfection and therefore offers useful insight for serological testing strategies, lockdown easing, and vaccine development.


2020 ◽  
Author(s):  
Andrew McMahon ◽  
Nicole C. Robb

Background: The novel coronavirus SARS-CoV-2, which causes the COVID-19 disease, has resulted in a global pandemic. Since its emergence in December 2019, the virus has infected millions of people, caused the deaths of hundreds of thousands and resulted in incalculable social and economic damage. Understanding the infectivity and transmission dynamics of the virus is essential for understanding how best to reduce mortality whilst ensuring minimal social restrictions to the lives of the general population. Anecdotal evidence is available, but detailed studies have not yet revealed whether infection with the virus results in immunity. Objective: The objective of the study was to use mathematical modelling to investigate the reinfection frequency of COVID-19. Methods: We have used the SIR (Susceptible, Infected, Recovered) framework and random processing based on empirical SARS-CoV-2 infection and fatality data from different regions to calculate the number of reinfections that would be expected to occur if no immunity to the disease occurred. Results: Our model predicts that cases of reinfection should have been observed by now if primary SARS-CoV-2 infection did not protect from subsequent exposure in the short term, however, no such cases have been documented. Conclusions: This work concludes that infection with the SARS-CoV-2 virus provides short-term immunity to reinfection and therefore provides a useful insight for serological testing strategies, lockdown easing and vaccine design.


2021 ◽  
Author(s):  
Miguel López ◽  
Alberto Peinado ◽  
Andrés Ortiz

AbstractSince the first case reported of SARS-CoV-2 the end of December 2019 in China, the number of cases quickly climbed following an exponential growth trend, demonstrating that a global pandemic is possible. As of December 3, 2020, the total number of cases reported are around 65,527,000 contagions worldwide, and 1,524,000 deaths affecting 218 countries and territories. In this scenario, Spain is one of the countries that has suffered in a hard way, the ongoing epidemic caused by the novel coronavirus SARS-CoV-2, namely COVID-19 disease. In this paper, we present the utilization of phenomenological epidemic models to characterize the two first outbreak waves of COVID-19 in Spain. The study is driven using a two-step phenomenological epidemic approach. First, we use a simple generalized growth model to fit the main parameters at the early epidemic phase; later, we apply our previous finding over a logistic growth model to that characterize both waves completely. The results show that even in the absence of accurate data series, it is possible to characterize the curves of case incidence, and even construct short-term forecast in the near time horizon.


2021 ◽  
Vol 292 ◽  
pp. 03091
Author(s):  
Jiacheng Wang ◽  
Xianhao Xu ◽  
Zihan Xu

COVID-19 emerged in Wuhan, China, at the end of 2019 and then soon evolved into a global pandemic. The novel coronavirus inducing this pandemic is under extensive study held by researchers all over the world. We give out a comprehensive review of what we have known about this novel coronavirus, including the pathogenesis. Passive immunity, different strategies, and targets for vaccine development and antiviral drugs are introduced as therapeutic strategies. At last, many other properties of SARS-Cov-2 are discussed.


2021 ◽  
Vol 12 (2) ◽  
pp. 222-234
Author(s):  
Zeba Firdaus ◽  
Sushil Kumar Singh ◽  
Tryambak Deo Singh ◽  
Meenakshi Singh

The novel coronavirus, which emerged in China in late December 2019, is officially named as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). The rapid spread of the virus across the continent has disrupted human life in every aspect leading to health and economic crises. The World Health Organization (WHO) declared the novel coronavirus outbreak as a global pandemic on March 11, 2020. In spite of complete lockdown and quarantine efforts in many countries, the occurrence of infections continues to rise, with more than 88 million laboratory-confirmed cases and over 1.9 million deaths worldwide as on January 10, 2021. Since the beginning of the outbreak, lot of intriguing studies about the phylogenetic evolution, epidemiology, pathogenesis, transmission, clinical characteristics, and possible treatment of Corona Virus Disease 2019 (COVID-19) have been published. This review aims to provide an insight into the progress in this regard and provides a reference for future studies including general awareness. We have discussed the origin, transmission, and infection mechanism of coronaviruses in host cells as well as available treatment options with relevant case studies. Furthermore, the stages of vaccine development, types of vaccines, and candidate vaccines with their phases of clinical trial are also incorporated. In a nutshell, the article is an attempt to retrieve the latest information available on virus behavior, efficacy of the available drugs, and development of candidate vaccines on SARS-CoV-2.


Author(s):  
Ekta Shirbhate ◽  
Preeti Patel ◽  
Vijay K Patel ◽  
Ravichandran Veerasamy ◽  
Prabodh C Sharma ◽  
...  

: The novel coronavirus disease-19 (COVID-19), a global pandemic that emerged from Wuhan, China has today travelled all around the world, so far 216 countries or territories with 21,732,472 people infected and 770,866 deaths globally (as per WHO COVID-19 update dated August 18, 2020). Continuous efforts are being made to repurpose the existing drugs and develop vaccines for combating this infection. Despite, to date, no certified antiviral treatment or vaccine prevails. Although, few candidates have displayed their efficacy in in vitro studies and are being repurposed for COVID-19 treatment. This article summarizes synthetic and semi-synthetic compounds displaying potent activity in their clinical experiences or studies against COVID-19 and also focuses on mode of action of drugs being repositioned against COVID-19.


Axioms ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 18
Author(s):  
Marouane Mahrouf ◽  
Adnane Boukhouima ◽  
Houssine Zine ◽  
El Mehdi Lotfi ◽  
Delfim F. M. Torres ◽  
...  

The novel coronavirus disease (COVID-19) pneumonia has posed a great threat to the world recent months by causing many deaths and enormous economic damage worldwide. The first case of COVID-19 in Morocco was reported on 2 March 2020, and the number of reported cases has increased day by day. In this work, we extend the well-known SIR compartmental model to deterministic and stochastic time-delayed models in order to predict the epidemiological trend of COVID-19 in Morocco and to assess the potential role of multiple preventive measures and strategies imposed by Moroccan authorities. The main features of the work include the well-posedness of the models and conditions under which the COVID-19 may become extinct or persist in the population. Parameter values have been estimated from real data and numerical simulations are presented for forecasting the COVID-19 spreading as well as verification of theoretical results.


2021 ◽  
Vol 100 (4) ◽  
pp. 74-79
Author(s):  
I.M. Kagantsov ◽  
◽  
V.V. Sizonov ◽  
V.G. Svarich ◽  
K.P. Piskunov ◽  
...  

The novel coronavirus infection (SARS-CoV-2), which first appeared in Wuhan, China in December 2019, has been declared a global pandemic by WHO. COVID-19 affects people of all age groups. The disease in children is usually asymptomatic or mild compared to adults, and with a significantly lower death rates. Data on kidney damage in children with COVID-19, as well as the effect of coronavirus infection on the course of diseases of the genitourinary system, are limited, the risks of contracting a new coronavirus infection in children with significant health problems, including those with chronic kidney disease, remain uncertain. The pandemic has affected the activities of surgeons treating diseases of the urinary system in children. Since the prospects for the end of the pandemic are vague, it is necessary to formulate criteria for selecting patients who can and should be provided with routine care in the pandemic. The purpose of this review is to highlight the features of the clinical manifestations and treatment of children with COVID-19, occurring against the background of previous renal pathology or complicating its course.


2020 ◽  
Vol 6 (27) ◽  
pp. eabb9153 ◽  
Author(s):  
Xiaojun Li ◽  
Elena E. Giorgi ◽  
Manukumar Honnayakanahalli Marichannegowda ◽  
Brian Foley ◽  
Chuan Xiao ◽  
...  

COVID-19 has become a global pandemic caused by the novel coronavirus SARS-CoV-2. Understanding the origins of SARS-CoV-2 is critical for deterring future zoonosis, discovering new drugs, and developing a vaccine. We show evidence of strong purifying selection around the receptor binding motif (RBM) in the spike and other genes among bat, pangolin, and human coronaviruses, suggesting similar evolutionary constraints in different host species. We also demonstrate that SARS-CoV-2’s entire RBM was introduced through recombination with coronaviruses from pangolins, possibly a critical step in the evolution of SARS-CoV-2’s ability to infect humans. Similar purifying selection in different host species, together with frequent recombination among coronaviruses, suggests a common evolutionary mechanism that could lead to new emerging human coronaviruses.


2021 ◽  
Vol 10 (2) ◽  
pp. 01-05
Author(s):  
Augustine Owusu-Addo ◽  
Atianashie Miracle A ◽  
Chukwuma Chinaza Adaobi ◽  
Larissa Agbemelo-Tsomafo

COVID-19, also known as the ‘novel coronavirus disease 2019’, is a respiratory illness and the causative pathogen is officially named as ‘SARS-CoV-2’. Infections with SARS-CoV-2 have now been amplified to a global pandemic – as of April 3, 2020, nearly 1,018,000 cases have been confirmed in more than 195 countries, including more than 300,000 cases within the United States. Public safety guidelines are followed worldwide to stop the spread of COVID-19 and stay healthy. Despite COVID-19 is a respiratory illness with mode of invasion through the respiratory tract, not the gastrointestinal tract, an average food consumer is anxious and concerned about the food safety. Could an individual catch the deadly contagious COVID-19 from groceries brought home from the supermarket – or from the next restaurant takeout order? This brief review elucidates the epidemiology and pathobiological mechanism(s) of SARS-CoV-2 and its implications in food-borne infections, transmission via food surfaces, food processing and food handling.


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