COVID-19 lockdown: de-risking exit by protecting the lung with leukaemia inhibitory factor (LIF)

There are two key needs in COVID-19 management: (i) to reduce SARS-CoV-2 viral infection rate; and (ii) to reduce death rate of those infected - the subject of this commentary. The current WHO estimated global mortality rate is 3.4% (March 2020) and the global death toll has now past 200,000 (April 2020). Without therapy the COVID-19 pandemic is escalating exponentially: from the first reported death in Wuhan China 10th January 2020, it took 91 days for the global death toll to pass 100,000 - then a further 16 days to reach 200,000. A vaccination program will take 1–2 years to roll out, once safety and efficacy is proven. Anti-virals are being sought mainly amongst repurposed drug candidates but also with combinatorial screening of libraries, for example to block virus binding angiotensin converting enzyme 2 (ACE2) - ACE2 providing the receptor on cells that allows viral entry. Cell-based approaches include stem cells and exosomes but these will never meet scale of need whilst also carrying risk of viral transmission if contaminated. Countries have introduced Population control with social distancing and lockdown to isolate individuals: this has reduced infectivity rate - “R” - where R denotes the average number of people an infected person will spread the illness to. But, after lockdown, the virus remains: the probability of R increasing again is high. The new danger is exit from lockdown. Here, leukaemia inhibitory factor (LIF) represents an untapped resource to boost the lung's own resistance to developing COVID-19 - reducing risk of severe disease as nations cautiously leave lockdown to return to normality.