Treating the host.
One of the key values of
therapeutics is their potential in stabilizing patients prior to
subsequent interventions or their use as adjuncts to those
interventions. The settings where this may occur are varied and include
response to traumatic injury to control damage, treat infection and
alleviate pain. Other notable examples include the development of
anaesthesiology and sedation to enable the performance of surgery and
complex procedures, as well the development of non-depolarising
neuromuscular-blocking drugs as adjuncts to those surgical procedures
and of adjunctive chemotherapy to improve quality of life and survival
time. Of particular interest in this pandemic context has been the
centuries old development of agents to promote survival with infections.
Historically the focus was upon
identifying agents that would kill the invading species and not damage
the host. In more recent times the focus has moved to delineating the
treatment of the host from treatment and elimination of the infective
agent.
In 2016, Fedson highlighted the
treating of the host concept, based upon an understanding that a
beneficial clinical phenotype has been observed with a treatment and
this can be employed for the purpose of treating the host (3). This was
done in the context of emerging virus diseases, and more recently in the
context of severe COVID-19 infection (5). Consistent with this view Yan
et al. (6) drew attention to the need for agents to alleviate H5N1
virus-induced lung injury due to the limited strategies for treating
influenza virus infection.
The concept of treating the host is entirely complementary to
opportunities arising in the area of drug repurposing that we have
highlighted recently (7). In the case of COVID-19 disease this would
mean identifying drugs that are focused, not on the elimination of the
virus, but upon the survival of the patient with severe COVID-19
disease. This includes drugs approved for other indications that have
the beneficial phenotype for treating severe COVID-19 disease. The
fundamental advantages of this approach are; firstly, to buy needed time
for the concurrent development of anti-viral or vaccines, secondly to
provide health authorities a treatment insurance as they begin to
release the public from social isolation. We have highlighted this key
aspect recently in the context of Covid-19 disease (8). However this
very obvious but distinct suite of solutions to reduce the morbidity and
mortality from COVID has the potential risk of cutting across fixed
interests and previously effective methods of succeeding in grant
funding rounds, including silos of ‘ology disciplines, and pressures
from news cycles and campaigning for ineffective policies.
What is needed is the appropriate framework for treating the host, a
strategy for positioning this approach, and then implementation.