Could a common vaccine used for decades to protect against tuberculosis help shield health workers from COVID-19? While developing a specific immunisation against the coronavirus sweeping the planet will likely take many months, researchers are studying the potential benefits of the BCG shot, which many people around the world receive as children.
Laboratories and pharmaceutical firms are racing to find medicines to tackle COVID-19, which has infected more than a million people, killed at least 50,000 and for which there is currently no known treatment, vaccine or cure.
Children vaccinated with BCG suffer less from other respiratory illnesses, it is used to treat certain bladder cancers and it could protect against asthma and autoimmune diseases such as type 1 diabetes.
Researchers want to test whether the tuberculosis vaccine could have a similar effect against the new coronavirus, either by reducing the risk of being infected, or by limiting the severity of the symptoms.
The BCG vaccine does not directly protect against the coronavirus, but provides a boost to the immune system which may lead to improved protection and a milder infection, Radboud university said of the study.
The idea is that the innate immune system can be prepared, or “trained” to better combat attacks, thanks in particular to live attenuated vaccines, such as BCG or measles, which contained a weakened sliver of the original pathogen.
In the case of COVID-19, in addition to infection by the virus itself, some patients have also suffered excessive immune responses, with the uncontrolled production of pro-inflammatory proteins, cytokines.
“Vaccination, in particular against BCG, might help to better orchestrate this inflammatory immune response,” said Laurent Lagrost, Inserm research director who works on links between inflammation and the immune system.
The vaccine acts as a “military exercise in peacetime” so that the body can “fight the enemy effectively in wartime,” he said in an interview this week with French broadcaster BFMTV.