Our motivation

With the objective of contributing to the fight against the COVID-19 pandemic, members of the student council of Ecole Polytechnique - class of 1981 (Kès 81) performed an analysis of the rate of expansion of the disease in several countries in relation to the use of protective masks.
This analysis is not a substitute to in-depth scientific studies but its results are compelling enough to be widely shared.

The analysis and following recommendations are the signatories' only and do not reflect the position of the class of 1981 nor of any of its representative entities. Its vocation is to be completed and amended following an open-source model.

Countries where the use of protective masks is prevalent have not experienced an exponential pandemic growth even though they have different policies in terms of tests, confinement, border control, or even different health systems and hygiene practices.

The analysis is based on the comparison between the development rate of the epidemic by country compared to a theoratical calculation based on the observed use of protective masks and their published efficiency.

The analysis shows that the calculations are close to the observed data which clearly supports a correlation. Given the magnitude of the discrepancy for the rate of replication between countries promoting the use of masks (R0 at circa 1) and the others (R0 at circa 3), an underlying causal link is highly likely. This hypothesis is shared by numerous specialists in Asia, notably in China and South Korea, but not recognised in most Western countries.

The hypothesis that the generalised use of protective masks (or any other mean of limiting the propagation via aerosol or hand-to-face contact) significantly slows down the epidemic seems therefore extremely likely. Its contribution to the control of the pandemic propagation could be of the same magnitude as confinement, with other measures having only a second order effect. The main objective of the systematic use of masks is not only to protect the wearer (as is the case for medical staff) but to reduce the replication rate R0 and bring it down from 3 to circa 1.

We therefore recommend to launch the three following measures as soon as possible:

  1. Promote then make compulsory the use of protective masks in public spaces - be it homemade while the availability of certified products remains insufficient.
  2. Invest in local manufacturing of protective masks following the example set by China in mobilising their industry.
  3. Confirm by an in-depth scientific studies the above conclusions so as to target the most efficient measures.

The members of Kès 1981