Irish scientist instrumental in Covid-19 vaccine trial

Trial tests BCG vaccine’s potential to protect adults against the coronavirus

An Irish scientist is playing a lead role in one of the largest vaccine trials underway against Covid-19.

An immunologist originally from Wexford, Prof David Lynn is the director of systems biology at the South Australian Health & Medical Research Institute (SAHMRI) in Adelaide. Prof Lynn's work is focused on the BCG jab and whether it can protect adults against the coronavirus. Ordinarily BCG is given to infants to prevent tuberculosis.

He works alongside his wife and fellow scientist Dr Miriam Lynn from Dublin, also an immunologist.

The clinical trial will involve 10,000 healthcare workers in Australia, the Netherlands and Spain.


The trial is expanding to Europe due to the success Australia has had in controlling the Covid-19 pandemic. South Australia has had just one case in the last 20 days, said Prof Lynn.

The trial will first test whether BCG vaccination leads to fewer cases of Covid-19. Second, even if there is no difference in infection rates, it will test whether those who got the BCG jab suffered less severe disease.


Samples from volunteers will be used to look for antibodies to Covid-19 and investigate how the immune system responds after a BCG jab. It is suspected that the vaccine will prep defensive genes in innate immune cells, which are the first responders to germs. BCG seems to prime these frontline cells to respond better and faster.

Prof Lynn pointed to studies in Africa showing that BCG in infants reduced death by up to 50 per cent up to the age of five. This was, he says, was not explainable by a reduction in tuberculosis. "There is quite strong evidence now that the BCG vaccine can have beneficial non-specific effects," says Prof Lynn.

Studies in developed countries also indicate that BCG cuts down on serious respiratory illness, sepsis and hospital visits in children, says Prof Lynn. “We have known about its ability to modulate the immune system for quite some time.”

Health policy experts warn that countries must wait for clinical trials to prove or disprove whether BCG can reduce its symptoms before considering its use. “[BCG] is viewed as a potential interim solution, while a specific vaccine is in development,” said Prof Lynn. Most experts believe a vaccine will not be widely available for another 12 to 18 months.

If shown to work, BCG could be worth stockpiling for future emergencies. “It could be kept in the toolbox as a non-specific solution to respond rapidly to future pandemics,” said Prof Lynn.