BCG vaccine: What is it and could it protect against coronavirus?

Vaccine usually given to protect children from tuberculosis

(Getty Images/iStockphoto)

The Bacillus Calmette-Guerin (BCG) vaccine is usually administered to protect children from contracting tuberculosis, but a new study suggests it might also help protect against other infections, such as Covid-19.

It was first developed in 1921, but research conducted by the University of Exeter has found evidence that it may train the immune system to respond to a wide-range of viruses.

As a new trial begins to see whether or not the BCG vaccine could protect people from coronavirus, here’s everything you need to know about it.

What is the BCG vaccine?

The BCG vaccine was developed to protect against tuberculosis, which is also known as TB.

It was launched in 1921 and is typically administered to adults aged 16 to 35 who might be at risk of TB because of the work they do.

For example, healthcare workers are often given the BCG jab.

It is 70 to 80 per cent effective against the most severe forms of TB.

How is the BCG vaccine administered?

The BCG vaccine is usually given in the upper arm as an injection.

It typically leaves a small scar.

What is tuberculosis?

The NHS describes TB as a potentially serious bacterial infection that affects the lungs and sometimes other parts of the body, such as the bones, joints and kidneys.

It can also sometimes lead to menangitis.

Symptoms include weight loss, high temperature, loss of appetite, and swellings in the neck.

TB can be serious but can be cured if treated with the right antibiotics.

You can read more about TB on the NHS website.

Who should have the BCG vaccine?

The BCG vaccine is recommended to those with an increased risk of developing TB. This includes children who have recently arrived from countries with high levels of TB, such as those in Africa, the Indian subcontinent, parts of southeast Asia, parts of South and Central America, and parts of the Middle East.

Additionally those who have come into close contact with somebody infected with TB may be advised to get the BCG vaccine.

In the UK, routine BCG vaccinations were stopped in 2005 because of low rates of TB in the general population.

Why do people think the BCG vaccine could help protect people from coronavirus?

A new study conducted by the University of Exeter found that the vaccine stimulates the immune system in a way that could mean it protects the body from other viruses in addition to TB.

Professor John Campbell, of the University of Exeter Medical School, said: "Covid-19 has killed more than a million people globally, with well over 33 million people acquiring the disease, sometimes in its severest forms.

“BCG has been shown to boost immunity in a generalised way, which may offer some protection against Covid-19.”

Now, the University of Exeter is taking part in a trial that will see the BCG vaccine given to 10,000 people globally.

The study will look at whether the BCG vaccine reduces coronavirus infections or the severity of Covid-19 symptom.

“We're excited to be contributing to the large-scale, international study where we are seeking to establish whether the BCG vaccine could help protect people who are at risk of Covid-19,” added Professor Campbell.

"If it does, we could save lives by administering or topping up this readily available and cost-effective vaccination."