Could this be the answer to defeating corona?

Research suggests that countries with strong BCG vaccine programmes have lower Covid-19 death rates

With the death toll rising and no end in sight to coronavirus lockdown, it might seem that several dark weeks lie ahead. As well as claiming over 1,000 lives here, the Covid-19 crisis has shown how vulnerable my frontline colleagues in the NHS are. But a possible development may offer a chink of light.

As a cancer immunologist, I have been involved with a number of clinical trials involving vaccines and other immune therapies. One of these is a mycobacterial product known as IMM-101, which has proved an effective treatment in both melanoma and pancreatic cancer studies. Intriguingly, a number of participants in trials I have worked on have remarked that, since having this “vaccine”, they have not suffered any flu or cold symptoms, often having succumbed every winter previously. Many were elderly, with more than one serious illness.

More recently, I was asked by colleagues in Norway, with whom I have collaborated on a therapeutic HIV vaccine programme, to help with a Covid-19 inoculation they have manufactured, and which is being produced for trials. I suggested swapping the vaccine’s current adjuvant (an ingredient added to boost the immune response) with IMM-101. The result has now been supplied for pre-clinical studies.

It is encouraging that our candidate vaccine – along with several others around the world – is being made and tested, but, soberingly, it will not be available for some months. That’s why I would like to propose that, as a short-term immunity boost, NHS workers should be provided with IMM-101 shots.

IMM-101 is available immediately, and is safe, having been approved for cancer trials. It could quickly be used on frontline staff and I have asked colleagues to help design and agree on the best form a trial could take.

There will be obstacles to progress.

There is no proof that this will work on Covid-19, I am told repeatedly when I have proposed this. Statisticians tell me that anecdotes are meaningless. But IMM-101 shares properties with the BCG vaccine, which protects against tuberculosis, and may help us fill in the gaps.

My colleagues and I have dissected the mechanism of action of IMM-101 and have shown that it stimulates the innate immune system that protects us from attack by viruses. The cells stimulated by IMM-101 include natural killers (NKS) and secrete cytokines which are known to kill viruses.

Many of these properties are shared with the BCG vaccine. BCG is not as effective, nor as safe, as IMM-101 in the context of immune-boosting clinical trials (unlike the BCG, an IMM-101 shot can be given again if the reaction fades; the BCG can also cause ulcers and infections at the injection site). None the less, given its common basic properties with IMM-101, BCG does provide some fantastic statistical support for our proposal.

In particular, colleagues from America have published a paper in which they have tried to address a question that has been puzzling us all. Why are the mortality rates so different from country to country? For Covid-19, it appears that there may be a relatively simple answer. In the US, Italy and Spain, there have never been comprehensive BCG vaccine programmes, whereas countries like Japan, with a strong programme, have a low mortality rate. The UK used to have a programme when I was young but stopped it. We may therefore have a very mixed mortality rate depending on BCG exposure.

Support for this hypothesis comes from another source. A recent study showing that prior BCG exposure boosted the response to flu vaccination has led to colleagues proposing to inoculate frontline workers in the Netherlands. This has already been approved by their government. We have an even better product in IMM-101; it boosts the antiviral defences more effectively than BCG without the latter’s negative effects.

Here is an opportunity for Britain to make a significant contribution to the scientific battle against Covid-19 – and protect thousands of the country’s health workers at the same time. We can’t let it pass us by.