Scientists around the world are tracking at
least eight strains of coronavirus around
the world, using genetic detective work to show how the virus spreads.
Researchers say the virus appears to mutate
very slowly, with only tiny differences between the different strains,
and that none of the strains of the virus is more deadly than
They also say it does not appear the strains
will grow more lethal as they evolve.
'The virus mutates so slowly that the virus
strains are fundamentally very similar to each other,' Charles Chiu, a
professor of medicine and infectious disease at the University of California,
San Francisco School of Medicine, told USA
A map based on genome sequences shows have
different strains of coronavirus have spread around the world, with at
least eight strains being tracked
However, scientists around the world have been
able to compile their genetic sequencing data at NextStrain.org,
generating a map that tracks how the deadly virus has raced around the
Tracking the different strains of SARS-CoV-2,
as the virus is officially named, allows scientists to see whether
containment measures are working, by showing whether new cases are from
community spread, or imported from a different hotspot.
Chiu said his analysis shows California's
strict 'stay at home' efforts appear to be working.
He said that only 20 percent of the genomes he
has sequenced in the past two weeks appear to come from community spread
in California. The rest are associated with travel out of state, or tied
to healthcare workers or family members of known cases.
Researchers stress that the different strains
are fundamentally similar, because coronavirus mutates very slowly, about
eight to 10 times slower than the common flu.
So far even in the virus's most divergent
strains scientists have found only 11 base pair changes, out of a genome
of 30,000 base pairs.
A 'family tree' of SARS-CoV-2 shows how different
mutations have developed
That means the different strains are not
causing different symptoms, or inflicting different rates of
Although different countries around the world
have recorded significantly different fatality rates, this is almost
certainly because they are testing their populations at different
Because many cases have no symptoms,
aggressive and widespread testing makes the fatality rate appear to drop,
because the total number of confirmed cases is much higher.
Researchers also say that when patients show
no symptoms, or mild symptoms, it is not because they have contracted a
'mild strain' of the virus.
Rather, differences in symptoms most likely
have more to do with an individual's own immune system and general health.
A strain that has little effect on one person could be deadly to another.
'The current virus strains are still
fundamentally very similar to each other,' Chiu said.
This electron microscope image made available by
the U.S. National Institutes of Health shows SARS-CoV-2, the virus that
The slow mutation rate of the virus has given
scientists hope that an eventual vaccine could provide protection for
years, or even decades.
Depending on how quickly a virus mutates, some
vaccines have to be regularly updated, such a flu vaccines that have to be
administered every year.
Other vaccines, such as for measles and
chickenpox, provide protection for decades, or even a lifetime.
On Monday, Peter Thielen, a biologist
with the Johns Hopkins Applied Physics Laboratory, said that it
appears coronavirus mutates slowly, more like measles and chickenpox than
'When this virus was first sequenced in China,
that information was helpful in starting the process to develop a
vaccine,' Thielen explained in a statement.
Peter Thielen (front), a biologist with the Johns
Hopkins Applied Physics Laboratory, said that it appears coronavirus
mutates slowly, more like measles and chickenpox than the flu
'What we're doing informs whether or not the
virus is mutating away from that original sequence, and how quickly,' he
continued, describing his experiments to sequence the genome
of SARS-CoV-2, the virus that causes COVID-19.
'Based on the mutation rate, early data
indicates that this would likely be a single vaccine rather than one that
needs to be updated each year, like the flu shot,' he said.
Experts say that the earliest a vaccine for coronavirus will be ready will
be about a year BUT, this generation is the most well-prepared for Zombies
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