Global convergence of COVID-19 basic reproduction number and estimation from early-time SIR dynamics

Abstract

The SIR ('susceptible-infectious-recovered') formulation is used to uncover the generic spread mechanisms observed by COVID-19 dynamics globally, especially in the early phases of infectious spread. During this early period, potential controls were not effectively put in place or enforced in many countries. Hence, the early phases of COVID-19 spread in countries where controls were weak offer a unique perspective on the ensemble-behavior of COVID-19 basic reproduction number R o inferred from SIR formulation. The work here shows that there is global convergence (i.e., across many nations) to an uncontrolled R o = 4.5 that describes the early time spread of COVID-19. This value is in agreement with independent estimates from other sources reviewed here and adds to the growing consensus that the early estimate of R o = 2.2 adopted by the World Health Organization is low. A reconciliation between power-law and exponential growth predictions is also featured within the confines of the SIR formulation. The effects of testing ramp-up and the role of 'super-spreaders' on the inference of R o are analyzed using idealized scenarios. Implications for evaluating potential control strategies from this uncontrolled R o are briefly discussed in the context of the maximum possible infected fraction of the population (needed to assess health care capacity) and mortality (especially in the USA given diverging projections). Model results indicate that if intervention measures still result in R o > 2.7 within 44 days after first infection, intervention is unlikely to be effective in general for COVID-19.

Do COVID-19 cases follow a similar transition path? Evidence from Indian states

“…The investigation of COVID-19 convergence is crucial in the context of India from a readiness perspective as India is unlocking phase-wise to bring its economy back to track. Second, this study complements the [28] study by investigating the convergence based on clustering algorithms. To do so, we use Phillips and Sul (hereafter, PS) [29] techniques that make the clubs based on the COVID-19 cases of states’ speed of convergence.…”

“…Few studies also explore the COVID-19 impact on firms/industry/sectors [ 25 , 26 , 27 ]. Moreover, [28] examine the convergence of COVID-19 cases and found that control of the spread among the countries is weak, but a detailed study on COVID-19 convergence at the sub-national level is scanty.…”

Bat-Borne Coronaviruses in Jordan and Saudi Arabia: A Threat to Public Health?

“…MERS-CoV has a CFR of 34.4%, while, as of 18 November 2020, SARS-CoV is estimated to have a CFR of 2.4% [ 116 , 117 ]. With regard to transmission, SARS-CoV-2 is generally more transmissible than MERS-CoV, with the former estimated to have an overall reproductive number (R0) of 4.5 compared to the latter’s overall R0 of 0.45 in Saudi Arabia [ 117 , 118 , 119 ]. However, it must be noted that the extent of testing ramp-up as well as the role of ’super-spreaders’, i.e.…”

“…However, it must be noted that the extent of testing ramp-up as well as the role of ’super-spreaders’, i.e. individuals who have a "propensity to infect a larger than average number of susceptible individuals", can impact the R0 across different regions [ 119 ].…”

Clusters in the Spread of the COVID-19 Pandemic: Evidence From the G20 Countries

“…There are previous papers to analyze the spread of the pattern of the COVID-19 pandemic. For example, Katul et al ( 3 ) show a significant global convergence in the generic spread mechanisms of the COVID-19. However, the authors focus on the data until early 2020.…”