1 August 2020 | New Scientist | 9says Gilbert. “Immunity to
pathogens and vaccines is not
necessarily the same,” she says.
“The vaccine may provide
longer-lived immunity.” Fears
of decreasing immunity after
infection are probably overstated
too, she says: “It’s usual for
antibodies to reach a peak level
and then decline over time.”
Once we have one or more
effective vaccines, Gilbert thinks it
should be given first to healthcare
workers, both to protect them
and to prevent transmission
within hospitals and care homes.
“That is where the vaccine can
have most impact,” she says.
The hope of many is that normal
life can resume once a vaccine is
available, but this will take time.
“It won’t be available to everyone at
the same time and the vaccine may
not work very well in older people.
If that is the case, we need the rest
of the population to be vaccinated
to prevent transmission and
protect the vulnerable.” ❚
AS THE World Health
Organization (WHO) baldly
reminds us, “there are no specific
vaccines or treatments for
COVID-19”. However, trials of
treatments are taking place.
Some have shown promise
in helping those infected
by calming an overreacting
immune system or targeting the
coronavirus – either by destroying
it or stopping it from replicating.
Dexamethasone, a widely
available steroid that dampens
the immune response, became
the first medicine shown to
reduce deaths in covid-
patients. The RECOVERY trial
of more than 2000 people
found that it reduced deaths
in people on mechanical
ventilators by a third – and by
a fifth in those who received
oxygen but not ventilation.
“The trial showed it is
beneficial to those who are
severely affected,” says Sheuli
Porkess at the Association
of the British Pharmaceutical
Industry. It is now being used
by the National Health Service
in the UK to treat covid-19.In June, the US bought up
virtually all global stocks of
the drug remdesivir, an antiviral
that suggested promise against
Ebola. The move came after
one trial found that it reduced
recovery time by four days in
covid-19 patients.
However, other studies have
yielded mixed results: one in April
showed no clinical benefit, while
an analysis last month by Gilead,
the company behind the drug,
indicated a reduced risk of death
in those severely affected bycovid-19. Gilead cautions that
more rigorous trials are needed.
The drug has received emergency
or conditional approval in
a number of countries. The
litmus test will come in a few
weeks with the results of the
international Solidarity trial.
Trials are also looking at
whether the anti-inflammatory
tocilizumab, which is already
used to treat arthritis, could be
beneficial against covid-19.
Another recent development
relates to an inhaler-based
treatment that delivers a protein
called interferon beta to the
lungs. A preliminary finding
showed that it reduced the risk
of patients going on to develop
severe covid-19 by 79 per cent,
compared with a placebo group.
However, this was a small, early
trial of the drug, called SNG001,
developed by UK firm Synairgen.
The blood plasma of covid-
survivors offers another possible
treatment because it contains
antibodies to the coronavirus.
An alliance of companies formed
in May to pool research on itsuse as a therapy for the disease.
There are no trial results so far.
New drugs might still emerge.
Last week, an analysis of
thousands of known drugs that
have been approved or are under
clinical investigation found 13
that inhibited the coronavirus’s
replication in cultured cells.
As well as trying to use existing
drugs to tackle covid-19, some
pharmaceutical companies are
exploring entirely new ones.
In addition, researchers
have started to rule out
certain drugs. For example,
hydroxychloroquine and
lopinavir-ritonavir haven’t been
shown to provide any benefit,
at least in hospital settings.
For now, the focus remains
on treating the most severe,
short-term problems caused
by the illness. But with growing
evidence pointing to longer term
symptoms, treatments will be
needed to tackle those too. ❚Dexamethasone was
the first drug shown
to cut covid-19 deathsThe hunt for treatmentsAdam VaughanJO
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Reduction in deaths of ventilated
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promising medicines?
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