(Recasts with expert comment, U.S. background, quotes)
By Kate Kelland
LONDON, Oct 23 (Reuters) - Researchers called on Friday for
more research into using blood from recovered COVID-19 patients
- or so-called convalescent plasma - as a potential treatment,
after a small trial of hospitalised patients in India found it
was of no benefit
The Indian results, published in the BMJ British Medical
Journal, found that the plasma, which delivers antibodies from
COVID-19 survivors to infected people, did not help hospitalised
patients fight off the infection, and failed to reduce death
rates or halt progression to severe disease.
The findings are a setback for a potential therapy that U.S.
President Donald Trump touted in August as a "historic
breakthrough", and one experts say has been used in some 100,000
patients in the United States already, despite limited evidence
on its efficacy.
Scientists not directly involved in the India study, which
involved around 460 patients, said its results were
disappointing but should not mean doctors give up hope
altogether on convalescent plasma.
They said further and larger trials are needed, including in
COVID-19 patients with milder disease and those newly infected.
"With just a few hundred patients, (the India trial) is
still much too small to give clear results," said Martin
Landray, a professor of medicine and epidemiology at Britain's
Oxford University.
"One could well imagine that the treatment might work
particularly well in those earlier in the course of the disease
or who have not been able to mount a good antibody response to
the virus of their own," he said. "But such speculation needs to
be tested – we can’t just rely on an educated guess."
While the United States and India have authorised
convalescent plasma for emergency use, other countries,
including Britain, are collecting donated plasma so that the
treatment could be widely rolled out if it is shown to be
effective.
The Indian researchers enrolled 464 adults with COVID-19 who
were admitted to hospitals across India between April and July.
They were randomly split into two groups - with one receiving
two transfusions of convalescent plasma alongside best standard
care, and the other getting best standard care only.
After seven days, use of convalescent plasma seemed to
improve some symptoms, such as shortness of breath and fatigue,
and led to higher rates of so-called negative conversion - a
sign that the virus is being neutralised by antibodies.
But this did not translate into a reduction in deaths or
progression to severe disease by 28 days.
Ian Jones, a Reading University professor of virology,
agreed with Landray that plasma may be more likely to work very
soon after someone contracts COVID-19.
He urged these and other researchers to continue to conduct
trials, and to do so in newly diagnosed patients.
"We still do not have enough treatments for the early stage
of disease to prevent severe disease and until this becomes an
option, avoiding being infected with the virus remains the key
message," he said.
(Reporting by Kate Kelland
Editing by Peter Graff and Frances Kerry)