as
the world grapples with the effects of
the
covid-19
pandemic
,
new
versions of the
deadly virus have put health officials on alert and triggered new lockdowns.
the united kingdom, brazil, south africa and denmark have all had variants of sars-cov-2 (the virus that causes covid-19 disease)
pop up with varying degrees of severity. it
has us wondering: what exactly
are
variant
s
and how dangerous are they?
all viruses mutate
all viruses naturally mutate, and sars-cov-2 is no different.
sars-cov-2
has mutated thousands of times since it was first discovered more than a year ago. m
ost
variants
, of any virus,
die off quickly if the mutation makes it less effective at attaching to a host and spreading. but sometimes a virus mutates and develops a kind of competitive advantage over other viruses, allowing it to spread more easily.
“
what viruses do is they introduce mutations into their genome pretty quickly when replicating, changing the virus’ structure a little, and those mutations that confer a benefit to the virus can grow and become a predominant strain
,” said dr. john p. haran,
clinical director of the umass center for microbiome research,
in an
interview with umass news
.
while some variants spread because their mutation has made them more effective, others spread because of circumstance. a new variant may be weaker than the version it was copied from, but it spreads quickly because of the environment it is exposed to — a phenomenon researchers call the
“founder effect”.