Covid: what we now know about the means to protect yourself

- It's in the air

At the start of the pandemic, health authorities insisted a lot on hand washing to prevent transmission of Covid.

But in the course of 2020, a consensus emerged among scientists: more than through soiled hands that we wear to our nose or mouth, this disease is transmitted massively via aerosols, clouds of particles that we emit when we breathe and, more again, when we speak, shout or sing.

In a closed and poorly ventilated room, these aerosols can float in the air for a long time and move throughout the space, greatly increasing the risk of infection.

Despite this, the importance of aeration - which disperses these contaminated clouds, like cigarette smoke - is not always well understood by the general public.

"I think there was a communication error: we were not clear enough on the aeration, we scientists", recently assured AFP Arnaud Fontanet, member of the Scientific Council which guides the government French.

"When scientists talk about barrier gestures, we have to make it clear to people that aeration is part of it," he added.

- Flip-flop on the masks

As a direct consequence of the awareness of aerosol transmission, the discourse on masks has radically changed in two years.

At first the World Health Organization and many governments repeated that masks should be used only by caregivers, patients and their close relatives, and not by the general public.

A surgical mask, May 19, 2020 in Toulouse Lionel BONAVENTURE AFP / Archives

But in the eyes of supporters of the general wearing of masks, this speech was above all intended to avoid a shortage among caregivers.

From spring 2020, a change of course: the mask has become an essential tool in the fight against the pandemic, and its use has even been made compulsory at times.

As more contagious variants emerge, simple, less filtering fabric masks have been abandoned in favor of the surgical mask, which has become a symbol of the Covid years.

And with Omicron's takeover, which is extremely contagious, many scientists are now advising to switch to the FFP2 mask indoors.

More fitted to the face and more filtering, this mask is therefore more protective, but also more restrictive to wear.

- Vaccines: a turbo effect ...

The pandemic has taught us that it is possible to design new vaccines against an unprecedented disease and then start administering them worldwide in less than a year.

Previously, this process took ten times longer.

In early January 2022, just over a year after the start of the global vaccination campaign, around half of the planet's population is fully vaccinated against Covid, according to the UK University of Oxford website Our world in data.

On the other hand, what was foreseeable from the start has been confirmed: access to vaccines is very unequal between poor and rich countries.

"If we put an end to this inequality, we put an end to the pandemic", hammered the director general of the WHO, Tedros Adhanom Ghebreyesus, in his message of the New Year. His goal is to "vaccinate 70% of the people in all countries by July. "

- ... but not magic

Vaccination has been the primary tool in the fight against the pandemic: without it, the toll would have been much heavier since it protects against serious forms of the disease.

However, some of the hopes she had raised have not been confirmed.

Originally, it was hoped that quickly vaccinating the planet would put an end to the pandemic.

We now know that this will not be the case, because vaccines do not prevent the transmission of Covid and their effectiveness decreases over time.

This efficacy is also lower against the latest variants - now Omicron and, before it, Delta - than it was against the historical strain of the coronavirus SARS-CoV-2.

All this prompted rich countries to step up their recall campaign to restore the effectiveness of vaccines against the infection.

But it is not yet clear how long this effect will last.

Betting everything on reminders, even if it means having to multiply them, could therefore only be a short-term strategy, warn specialists.

"No country will be able to get out of the pandemic with booster doses", warned Tedros Adhanom Ghebreyesus at the end of December.

"Vaccines will not end the pandemic on their own," Maria Van Kerkhove, WHO technical manager for Covid, added Monday on Twitter, citing other complementary tools: "Surveillance, testing, 'isolation, treatments, ventilation, masks or distancing ".

© 2022 AFP