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By Deena Beasley
Dec 14 (Reuters) - The Omicron coronavirus variant has been
detected in 77 countries since it was first identified three
weeks ago, fueling concerns that its large number of mutations
will help it spread faster and evade protection provided by
COVID-19 vaccines or prior infection.
Scientists await answers to these important questions:
IS IT MORE CONTAGIOUS?
The fast-spreading Delta variant remains dominant worldwide,
and it is unclear whether Omicron is inherently more contagious
than its predecessor, the World Health Organization (WHO) said
in a brief issued on Sunday.
Early data suggests that the new variant is spreading faster
than previous versions of the virus. In South Africa, the UK and
Denmark, the number of new Omicron infections has been doubling
every two days - "an alarming rate of growth," according to Dr.
Eric Topol, director of the Scripps Research Translational
Institute in La Jolla, California.
The Omicron variant accounted for about 44% of infections in
London on Monday and was expected to become the dominant version
of the virus there within 48 hours.
WHAT TYPE OF ILLNESS DOES IT CAUSE?
Scientists say it is still too early to know whether
Omicron causes more or less severe COVID-19 than previous
versions of the virus.
In South Africa, scientists have said they see no sign that
the Omicron variant is causing more severe illness. Hospital
data found that COVID-19 admissions were rising sharply in more
than half of the country's nine provinces, but there have been
comparatively few deaths and indicators such as the median
length of hospital stay have been reassuring.
Among the 43 people identified as having the Omicron variant
in the United States, most reported mild symptoms including
coughing, congestion and fatigue.
People so far infected with Omicron have largely reported
mild illness likely because many have at least some immunity
from vaccinations and/or prior infection.
A more clear picture of Omicron's severity will come from
analyzing outcomes for a larger number of infected people,
particularly older, unvaccinated, previously uninfected
patients.
CAN IT RE-INFECT PEOPLE OR EVADE VACCINE PROTECTION?
The Omicron variant has about 50 mutations not seen in
combination before, including more than 30 mutations on the
spike protein the coronavirus uses to attach to human cells.
Most current COVID-19 vaccines target that spike protein, making
the cluster of mutations potentially problematic.
In its latest report, the WHO said there were early signs
that vaccinated and previously infected people would not build
enough antibodies to ward off an infection from Omicron.
A small study from a South African research institute
suggested that Omicron could partially evade https://www.reuters.com/business/healthcare-pharmaceuticals/pfizer-covid-19-vaccine-partially-protective-against-omicron-bloomberg-news-2021-12-07
protection from two doses of the Pfizer Inc vaccine.
The drugmaker and its partner, BioNTech, said a third
booster dose https://www.reuters.com/business/healthcare-pharmaceuticals/biontech-pfizer-say-test-shows-3-doses-vaccine-neutralise-omicron-2021-12-08
of their vaccine was better able to neutralize Omicron in the
laboratory. These findings will need to be compared with how
vaccinated people fare in the real world against Omicron.
A UK government brief on Friday said early estimates suggest
vaccine protection against symptomatic disease is significantly
lower with Omicron infection compared to the Delta variant,
although a booster dose led to vaccine effectiveness of 70% to
75% soon after the extra shot.
ARE CURRENT TREATMENTS STILL EFFECTIVE?
Omicron's mutations are expected to reduce the effectiveness
https://www.reuters.com/business/healthcare-pharmaceuticals/lab-test-eli-lilly-regeneron-antibody-therapies-lose-out-against-omicron-2021-12-14
of certain manufactured antibody treatments, including some
sold by Regeneron Pharmaceuticals and Eli Lilly & Co
. Drugmaker GSK last week said its antibody-based
COVID-19 therapy with U.S. partner Vir Biotechnology was
effective against the Omicron variant in lab tests.
Experimental antiviral pills - such as Pfizer Inc's
Paxlovid and Merck & Co Inc's molnupiravir - target
parts of the virus that are not changed in Omicron. These drugs
are likely to become important weapons if vaccine-induced and
natural immunity are threatened.
(Reporting By Deena Beasley
Editing by Bill Berkrot)
