New discovery of a long-standing vaccine may help fight SARS-CoV-2

There is currently no vaccine against SARS-CoV-2 virus that caused the Covid-19 pandemic to be spread globally. However, scientists in several countries are testing tuberculosis vaccines to see if this vaccine can boost the immune system to reduce respiratory symptoms in people with Covid-19. or not.

Scientists are testing the BCG vaccine against tuberculosis to assess its ability to cope with the Covid-19 epidemic. Artwork: Reuters

Researchers in Australia and Europe are experimenting to assess the possibility of the Bacille Calmette-Guerin (BCG) vaccine introduced in the 1920s to fight tuberculosis, whether it can be used against Covid-19. or not. Clinical trials focused on two groups of people at high risk for Covid-19, including health workers and the elderly.

Here are the results that scientists have discovered and the problems they are still investigating more about the potential of this vaccine.

How can the vaccine against tuberculosis assist in treating other diseases?

The BCG vaccine contains a strain of TB bacteria that is still alive but weakened to help the body produce antibodies that attack the TB bacteria again. This process is called the adaptive immune response because the body creates a defense mechanism against a certain pathogenic microbe or disease after encountering these pathogens. Most vaccines produce immunity adapted to a specific disease.

However, unlike other vaccines, the BCG vaccine also has the ability to boost the innate immune system - a defense mechanism that already exists in the body to stop pathogenic or infectious microorganisms. A Guinea-Bissau study found that children who were vaccinated with BCG had a 50% lower mortality rate than those who were not vaccinated. This death rate is even lower than that of tuberculosis deaths. Several other studies have found similar reductions in respiratory cases among adolescents and the elderly.

What scientists still do not know

Scientists currently do not have data on the effectiveness of BCG vaccine for corona virus in general and SARS-CoV-2 virus in particular.

In addition, there are many types of BCG vaccines with different abilities to protect against different types of tuberculosis bacteria. Scientists will now need to determine which BCG vaccine has the best ability to boost the immune system against the Covid-19 disease.

Who should get the BCG vaccine?

Scientists say it will take several months for the results of the BCG vaccine against Covid-19 resistance. Meanwhile, experts also recommend that people should not rush to get the vaccine because it has not been tested extensively in adults and may even be harmful. In addition, if a BCG vaccine "fever" against Covid-19 occurs, this could create a shortage of vaccines to prevent tuberculosis in children.