A new weapon against Covid-19? Especially for diabetics. Several researchers from different countries announced on Thursday the first results of clinical trials on the possible effectiveness of BCG, one of the oldest vaccines in the world, in the face of the coronavirus responsible for the current global pandemic.
Thus, since Wednesday and until Friday, the Institut Pasteur de Lille, in the North, is hosting the 3rd international congress of BCG, acronym of bilié de Calmette et Guérin. The first took place in 1948 in Paris. BCG is above all this century-old vaccine used against tuberculosis and remained compulsory in France from 1950 to 2007, to fight against this scourge.
“Immunity might have a memory”
But for a year and a half, around fifteen countries have been carrying out work to verify its potential anti-Covid power. Many specialists were thus invited to Lille to take stock of scientific advances, at the initiative of Professor Camille Locht, research director at Pasteur Lille. It is also in this institute that the original strains of BCG have been preserved for a century.
“We started from a series of observations showing that vaccinated children were protected from other infectious respiratory diseases,” explained Camille Locht a year ago to 20 Minutes. This is particularly the case in Africa where the BCG vaccination rate is very high. “
This efficiency against other related pathologies seems moreover a specificity of live vaccines such as BCG. “Immunity might have a memory,” the researcher still wonders. We believe that it is this adaptive mechanism that would make it possible to be effective. “
A vast study still to be consolidated
Unfortunately, the potency of this vaccine could not be proven in a study carried out in the Netherlands on elderly people in retirement homes. “No clear sign of protective effects, regrets Camille Locht. We just observe a small difference in the severity of the disease if we are vaccinated or not, but nothing conclusive. “
On the other hand, another study, in the United Arab Emirates, on healthcare personnel, shows more encouraging results. “The virus infection seems to decrease with vaccination, but the results are statistically weak,” notes Camille Locht.
A little more solid is the study led by Australian infectious disease specialist Nigel Curtis. The latter managed to develop a large-scale clinical trial in five countries: Australia, Brazil, Spain, Great Britain and the Netherlands. “We see different things in immune responses depending on whether or not you are vaccinated. But the results have yet to be consolidated”, cautiously indicates his Lille counterpart.
Hope for type 1 diabetics
In fact, it was in the United States that the trials provided the most spectacular conclusions. Initially, the study, which began two years ago with people with type 1 diabetes, did not target Covid. “And then, with the arrival of the epidemic, it was refocused,” says Camille Locht. After three vaccinations, we observe that BCG, this time, protects 100% ”. An epilogue which largely maintains hope.
“If BCG manages to show real effectiveness, it will be useful for the next epidemics of respiratory viruses”, estimates the researcher. Because the more vaccines we have, the less difficult the epidemic will be to fight worldwide.
The debate continues on BCG