Kicking goals against TB

Six TB vaccine contenders, developed by five different research institutions, are now being tested in three countries: South Korea, France and Australia (at JCU).

“The testing is standardised in each lab. In addition to the six potential new vaccines, we’re also testing the existing vaccine – BCG – and we have a control group which will receive no vaccine,” said Associate Professor Andreas Kupz, JCU’s TB Vaccinology Group leader.

“It’s a blind study, so none of us knows which vial contains which contender.”

To make it through to the next round of the competition, the vaccines will need to pass three challenges.

Tests on mice will assess the efficacy of the potential vaccines – how effective they are at preventing or slowing the disease’s progression in the lungs.

The contenders will also be tested for safety, particularly in terms of potential effects on vulnerable, immune-compromised recipients.

“The third hurdle is a mathematical one – an algorithm which was actually devised by some of our colleagues in the JCU TB Immunology Group and bioinformatics specialist Dr Ashley Waardenberg,” Associate Professor Kupz said.

“It’s a mathematical model that helps to prioritise global funding for potential new TB vaccines. It assesses the new candidate’s chances of outperforming the existing vaccine, BCG. This is important because trialling a new vaccine can cost up to a billion dollars.

“Unfortunately, the fact that our colleagues developed the model doesn’t give us a home-ground advantage, but we’re very proud of their work, which is attracting interest as an evaluation tool for vaccines for other infectious diseases such as influenza and COVID-19.”

The first round of the TB vaccine tournament will conclude in September 2023.  A maximum of three contenders will progress to round two.

“Of course, we hope our vaccine will make it to the next round, but this really is like the World Cup for us – we’re excited to have come this far. We’re working with the best in the world, and taking part in the testing is helping us further develop our skills,” Associate Professor Kupz said.

“It will be great if our JCU vaccine outperforms others from around the world. But at the end of the day, if this tournament uncovers one promising new vaccine against TB, that could save millions of lives and we’ll have been part of a great achievement.”

During the first-round tests two methods of vaccine delivery will be trialled: two laboratories will test the usual method of administering the vaccine as a subcutaneous injection, while another two sites will test intranasal inhalation.

“JCU’s TB researchers have already done quite a bit of work on nasal administration, similar to nasal sprays and asthma puffers,” Associate Professor Kupz said.

“We’re interested in those approaches because they allow us to better target the lung, which is the main site of TB infection.

“There’s a lot of work to be done on how to deliver a standard dose this way, but scientific interest is growing. If we can vaccinate babies that way rather than with a needle, vaccination day is going to be a lot easier for everyone involved.

“In the second round of the tournament, all of the potential vaccines that are still in the competition will be tested in nasal and subcutaneous administration at all involved laboratories, so we’ll be watching those results with interest.”

ABOUT TB and BCG

• Tuberculosis (TB) claimed 1.6 million lives globally in 2021.*
• Drug-resistant strains are increasing.
• The current TB vaccine, Bacille Calmette–Guérin (BCG), was introduced over a century ago (in 1921).
• It is still universally used to prevent TB in children, but protection wanes in adolescence. This leaves adults vulnerable to contracting the disease – and transmitting it to others.
• The need to develop a new vaccine that provides greater immunity is imperative.

* https://www.who.int/news-room/fact-sheets/detail/tuberculosis

Source: James Cook University