The effectiveness of all anti-COVID measures, a puzzle for scientists

What measures are the most effective against COVID-19? After almost two years of pandemic, and a tangle of studies and essays, it is difficult to compare, according to a vast recently published compilation study.

“We still lack excellent quality results on SARS CoV-2,” the virus that causes COVID-19, “and on the effectiveness of public health measures,” summarizes this study published Wednesday in the British Medical Journal ( BMJ), one of the leading journals in the scientific world.

This study is one of the first to comprehensively evaluate the entire palette of options against COVID-19.

Since the onset of the pandemic at the beginning of 2020, the world has been a laboratory of measures of all kinds, from strictly medical to social and even political: border closures, confinements in different degrees of the population, obligation to wear a mask, forced or recommended vaccination …

Studies have been partial on each of these solutions. This new report published by the BMJ encompasses them all and assigns them a level of importance based on their scientific rigor.

70 studies

From some 70 studies, researchers conclude that “washing hands, wearing a mask and applying physical distance” are effective measures to reduce the spread of the virus.

However, this impact is not decisive, and as for the rest of the options, the researchers are not even certain about how they were studied or applied.

“Due to the heterogeneity of the studies, it was not possible to develop a meta-analysis on the effects of quarantines and isolation measures, strict confinements, (as well as) the closure of borders, schools and workplaces,” they acknowledge. .

A meta-analysis allows not only to analyze in depth the results of different studies, but also to combine them, for example, to develop public policies.

The authors of this report acknowledge that they have not even been able to assess the rigor of research on the effects of room or closed room ventilation. And this despite the fact that this measure is massively recommended and used to fight a virus that is transmitted by air.

The BMJ article does not rule out the usefulness of these measures. It simply explains that in many cases, the studies that were done did not contain enough data, or were not done with the breadth or time necessary.

In some cases, the problem is the field of study, contrary to the work that has been done with anti-COVID vaccines or medical treatments.

Social measures, such as confinement or the use of masks, have been used simultaneously in all countries, and therefore it is difficult to address them in isolation. In some cases the measure was mandatory, in others a simple recommendation.

What follows from the experiences is that some initiatives, such as hand washing, are actually indications of other effective ways to act against the virus.

Washing your hands a priori should not have a great impact on an airborne virus. But people who wash their hands have other types of protective behaviors such as “avoiding crowds, keeping a distance and wearing a mask” estimate other researchers in a comment published separately in the same journal.

But scientists do not falter in their attempt to establish a general pattern, based on separate studies.

“We need more abundant and better quality research,” explains scientists, including Australian professor Paul Glasziou. The lack of rigor “is a tragedy in this pandemic,” they warn.