Studies underway to see if TB vaccine lessens COVID-19 symptoms

Trials have started around to world to see whether the BCG vaccine, which is routinely offered to babies in Nunavut to protect them from tuberculosis, could also help lessen the symptoms of COVID-19 among health workers.

There is evidence that the BCG vaccine can activate the immune response to provide cross-protection. In previous studies, Danish researchers found the vaccine prevents about 30 per cent of infections in the first year after it’s given.

Dr. Anna Banerji, a pediatric infectious disease specialist at the University of Toronto, who has worked widely in Nunavut, said she still has doubts about this vaccine’s ability to tackle the new coronavirus.

“They have likely given BCG in China … and clearly that didn’t work. Inuit babies get BCG but they still have extremely high rates of TB,” said Banerji, who has promoted immunization programs among Nunavut babies with antibodies to the respiratory syncytial virus.

All Nunavut babies are offered the Bacille Calmette-Guérin, or BCG, vaccine. It’s believed to offer 80 per cent protection against TB for 15 years. Yet in Nunavut, rates of TB remain roughly 30 times higher than elsewhere in Canada.

While the BCG vaccine doesn’t prevent TB in all cases, it’s believed to help prevent the more serious related diseases that children might get, such as TB-related meningitis, according to the Public Health Agency of Canada.

Nunavut’s Department of Health said in a statement to Nunatsiaq News that it is aware of past and ongoing studies regarding vaccines and treatments for COVID-19.

“The Department of Health is committed to using evidence-based protocols to treat all infectious and communicable diseases. When clinical trials produce a viable treatment or vaccine that is approved for use in Canada, the Department of Health will employ it in Nunavut,” the statement said.

Meanwhile, researchers are giving a serious second look to the BCG vaccine, which was first developed 100 years ago, after a 2016 study found the vaccine was associated with a reduction in “all-cause mortality.”

To test how the BCG works in the fight against COVID-19, infectious disease researchers in Australia will roll out a clinical trial involving 4,000 health care workers, the Murdoch Children’s Research Institute in Melbourne announced on March 28.

The director-general of the World Health Organization, Tedros Adhanom, who has called for global support and assistance in the fight against COVID-19, has endorsed the new trial, the institute said.

The trial, led by Nigel Curtis, a clinician-scientist who leads the institute’s Infectious Diseases Research Group, plans to build on previous studies, the institute said.

“We hope to see a reduction in the prevalence and severity of COVID-19 symptoms in health-care workers receiving the BCG vaccination,” Curtis said in the release.

Similar trials are being conducted in several other countries.

Dr. Ignatius Fong, an infectious disease specialist at the University of Toronto, told Nunatsiaq News that he felt that BCG wouldn’t be a treatment for COVID-19, but it “may make the disease milder in those who get infected.”

“There are many trials ongoing in the world now and we may have some preliminary results in a few weeks,” Fong said.