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In the search for a cure for COVID-19, scientists have also searched for older solutions that have helped humanity rid itself of infectious diseases. The BCG vaccine, for example, is an old vaccine, originally developed for tuberculosis, but which has a stimulating effect on the immune system and, therefore, offers an effective preventive action against other infections. It could also have an effect against COVID-19. This hypothesis is under study, and one of the researchers who relied on it, in the Netherlands, is the Romanian Mihai Netea, immunologist and professor at Radboud University in Nijmegen.
“The BCG vaccine is currently being studied around the world, there are between 10 and 12 studies being done in Europe, as well as in Africa, Australia and the United States. The study that we published (in early September, not) is actually started just before the COVID crisis, because we knew and suspected that the BCG vaccine might have beneficial effects against infections. The study started a year and a half or two ago, when we tried to use it against all types of infections, including flu , pneumonia, etc., in people over 65 years old ”, explained in Digi24 professor Mihai Netea.
What the Dutch study found before the COVID pandemic
“After following a group of patients who received BCG and a group of patients who received a placebo, I practically counted the number of infections they had during a year and noticed that people who received BCG had about 80 percent fewer respiratory infections than patients who received a placebo. This means that, for example, out of every ten people, around four had a respiratory viral infection in the control group and only one person had this infection in the group vaccinated with BCG, ”explained Mihai Netea.
“But that does not mean that we know what is happening against COVID-19,” said the professor. “Most of the respiratory infections that we saw were not COVID-19, they were pneumonia, flu, etc. The study started before the pandemic,” said Mihai Netea.
But, he says, there are some big global initiatives, even in the United States, where The effect of BCG on SARS-CoV-2 infection is currently being studied. In the Dutch study, conducted in a total of 200 patients, only a few COVID infections were recorded, their number being too small to be relevant.
When will we know for sure if BCG can also help against coronavirus?
“What we can say for sure is that, for example, there were no side effects from the vaccine, I had no problems and I realized that during the first wave of coronavirus in the Netherlands and Greece, where these studies were conducted, patients receiving BCG (and later got infected with SARS-CoV-2 – no.) they had fewer symptoms, but in that period not enough infections were collected, so we can draw a definitive conclusion ”, explained the researcher.
Three other large BCG studies are currently being conducted in the Netherlands: one on high-risk medical personnel, one on healthy elderly patients over 65 and one on hospital patients, also over 65, but who had a increased risk of COVID-19. All of these studies have several thousand patients each.
“We hope to see the effect of the vaccine before the end of the year.”said Professor Netea.
How long does the protective effect of the BCG vaccine last?
Because the BCG vaccine has this very broad effect on several types of infections, including bacterial ones, the estimated effect of its effectiveness is four to five years.
“If we can show that it has these beneficial effects, during this period, it can give us time to develop any specific vaccine against COVID-19 “, Mihai Netea pointed out.
“In fact, we do not know how long the vaccines that are being developed at this time will last (against COVID, no). There are some specific vaccines against other infections that can provide protection for up to 30-40 years. Instead, the vaccine against The flu, unfortunately, provides protection for only one year, so we don’t yet know exactly what will happen to the vaccines that are being developed now. From our studies we’ve done so far with the BCG vaccine, it appears to give protection for up to four or five years ”, added the researcher.
What is the secret to the “power” of the BCG vaccine?
In experimental studies, the BCG vaccine has been found to protect against both bacterial and viral infections, and even parasitic infections. For example, there have been studies on malaria.
“We have shown to healthy volunteers that it can protect against viral infections and can also provide partial protection against malaria in humans,” said Professor Netea.
How is that possible? “BCG very strongly activates the innate immune system, which has a very broad action, against all types of pathogens, both bacteria, viruses and parasites”, Explained the researcher.
What about the “cytokine storm”?
It is known that in COVID the phenomenon called “cytokine storm” often occurs, the overreaction of the immune system, which can lead to death. Under these conditions, isn’t the oversupply dangerous, an artificial stimulation of the immune system? Professor Netea was asked.
“We also asked ourselves this question and everyone wondered when we started this study. However, what is happening is different. What the vaccine does is Activate immune system. When the virus enters the body, an activated immune system prevents the virus from multiplying. As a result, we have a lot fewer viral particles in our blood, in our body, when we get vaccinated with BCG. These few viral particles will give a much less inflammation and much less cytokines, to protect the patient. When someone is not vaccinated, it can happen that at first there is a low immune response, which leads to an excessive multiplication of the virus, which in turn leads to systemic inflammation, with the cytokine storm, and this can lead to the death of the virus. patient. So basically it all depends on when the immune system is activated. If it is activated in time, at first, it can stop the viral multiplication. However, we should never give the BCG vaccine to someone who is already infected and is in the hospital. We will never treat you, precisely because of the risk of triggering an immune overreaction. But administered before, preventively, against the virus, it is successful. At least that’s what we think“Explained Professor Mihai Netea.
Is there enough BCG stock?
The Romanian researcher assures that if the efficacy of the BCG vaccine is also tested in the case of the coronavirus, the problem that could arise is related to stocks.
At the moment, the BCG vaccine can be produced, there are seven or eight manufacturers worldwide, and around 160 million doses are produced each year. The problem is that of these 160 million doses, 130 million are needed, since newborns in developing countries are all vaccinated against tuberculosis with this vaccine. So practically there are around 20-30 million doses left, which is definitely not enough.
“Once we can show that the BCG vaccine has a beneficial effect against COVID-19, it will be necessary for the current production in the world to accelerate very sharply to produce as many doses as possible.” noted Professor Mihai Netea.
Read also: Why are children better protected from the virulence of SARS-CoV-2 infections?
The approval of a vaccine should not be “pressured” politically
“In my opinion, no vaccine (anti-COVID – no) will be marketed, at least in the countries of the European Community or in the United States, if it does not have a very strong safety record. It would not be wise to speed up the vaccine too much, because it can exist, even if, for example, a vaccine generally has the effects that we want, protective effects, if it is initially approved without being absolutely sure that it has all the positive effects and that it does not have side effects, when there would be some complications in vaccinated people, at that time there could be a decrease in public confidence. The best thing would be to continue these studies, to show that the vaccine is effective, to show that it is safe, and when we know for sure that it is effective, that it has a very high level of safety, then we can administer it. Of course, any vaccine can have some side effects, but as long as they are less than the positive effect they give, this can be done at the population level. But these studies must be carried out to the end, without rushing and without pushing from a political point of view the approval of a vaccine ahead of its time, ”said Professor Mihai Netea.
Until then, if ongoing studies show it, maybe the old BCG vaccine is the time valve we need until a specific cure for COVID is found.
Editor: Luana Pavaluca
