The first vaccine developed in Spain to be tested on people to prevent covid-19 was first designed twenty years ago. It is a vaccine that had the initial objective "of shortening the treatment in patients infected with tuberculosis," explains Pere Joan Cardona, researcher at the Germans Trias i Pujol Hospital in Badalona who created it. As over the years it has been seen that, in general, vaccines against tuberculosis have reduced the incidence of respiratory diseases, scientists think that this vaccine could be used as protection against covid-19.
The vaccine initially designed and produced by Cardona - the first batches were made by him in the hospital laboratory - does not induce the formation of specific antibodies against the new coronavirus, but uses a different mechanism, known as trained immunity. "This is a mechanism about which there has been a lot of scepticism but of which there was already evidence in insects for years," the researcher explains. This vaccine is made up of fragments of the tuberculosis bacteria enriched with pieces of the wall of the microbe itself, which are known to help stimulate immunity. These substances produce a series of changes in the regulation of the DNA of some of the the immune system's cells, making them respond very quickly to any infection and reduce the concentration of invading viruses or bacteria in a short time. It is this ability to enhance the body's first response to infection that researchers want to use against coronaviruses.
To be able to do this safely and with guarantees of effectiveness, there is no other option but to launch the corresponding clinical trials. Although there are already some population-based studies suggesting that TB vaccines protect against covid-19, more specific studies are needed to demonstrate this, some of which are already underway. The clinical trial to study the usefulness of the Badalona vaccine that has just received the green light will take place in Argentina and is expected to involve 350 people over nine months. "In addition, we are working to carry out other trials in Italy, Spain and Mexico, which would total 1,500 people," explains Luis Ruiz, director of Ruti Immune, the company created to test, produce and market the vaccine. "The main objective of the trial is to demonstrate that the vaccine generates trained immunity in humans," he adds.
After these trials, it would have to be proven with more participatory studies that the vaccine protects against covid-19. In addition to this, there are about twenty trials worldwide to test the protection that TB vaccines provide against covid-19. The results of these studies are expected soon. If protection is confirmed, this would be very good news for the Badalona vaccine, as it would guarantee that the mechanism of trained immunity is useful in fighting the pandemic. On the other hand, Ruti Inmune, which has the participation of Archivel Farma, expects to increase its capacity to produce doses from two to twenty million per year during 2021.
One proven advantage of the Badalona vaccine is that it is safer than most other tuberculosis vaccines. Since it is made from fragments of the bacteria and not from whole inactivated or attenuated bacteria, it produces fewer side effects. Unlike the rest, this means it can be given to people who have a weakened immune system from diseases such as HIV or cancer. One of the other interesting aspects of this vaccine, and of tuberculosis vaccines in general, is that they induce an immunity that serves to fight a very wide range of diseases. In this sense, "not only can it be used for covid-19, but if there is another disaster like this one, which seems to happen periodically, it can also be used," explains Cardona. "It can even be useful for flu epidemics," he adds.