Quantification of the South African Lockdown Regimes, for the SARS-CoV-2 Pandemic, and the Levels of Immunity They Require to Work

TL;DR

This study quantifies South African lockdown regimes for COVID-19, analyzing their effectiveness based on the basic reproduction number, and estimates the immunity levels needed for these measures to be effective, highlighting their limited success.

Contribution

It provides a detailed quantification of lockdown regimes' effectiveness and immunity thresholds, offering insights into their actual impact during the pandemic.

Findings

Level-5 lockdown had $r_0=1.93$, not sufficient to contain the virus.

Level-3 and Level-4 lockdowns had $r_0$ of 2.34 and 1.69 respectively.

Lockdowns failed to meet objectives of curtailing the pandemic.

Abstract

This research quantifies the various South African lockdown regimes, for the SARS-CoV-2 pandemic, in terms of the basic reproduction number, $r_0$. It further calculates the levels of immunity required for these selfsame lockdown regimes to begin to work and predicts perceived values, should infections have been underestimated by a factor of 10. The latter results are compelling. The first, level-5 lockdown was a valiant attempt to contain the highly infectious, SARS-CoV-2 virus, based on a limited knowledge. Its basic reproduction number ($r_0 = 1.93$) never came anywhere close to the requirement of being less than unity. Obviously, it could be anticipated that the same would apply for subsequent, lower levels of lockdown. The basic reproduction number for the level-3 lockdown was found to be $2.34$ and that of the level-4 lockdown, $1.69$.The suggestion is therefore that the level-4 lockdown might have been marginally `smarter' than the `harder', level-5 lockdown, although its basic reproduction number may merely reflect an adjustment by the public to the new normal, or the ever-present error associated with data sets, in general. The pandemic's basic reproduction number was calculated to be $3.16$, in the Swedish context. The lockdowns therefore served to ensure that the medical system was not overwhelmed, bought it valuable time to prepare and provided useful data. The lockdowns nonetheless failed significantly in meeting any objective to curtail the pandemic.