On 26 November 2021, WHO designated the variant B.1.1.529 a variant of concern, named Omicron, on the advice of WHO’s Technical Advisory Group on Virus Evolution (TAG-VE). This decision was based on the evidence presented to the TAG-VE that Omicron has several mutations that may have an impact on how it behaves, for example, on how easily it spreads or the severity of illness it causes. Here is a summary of what is currently known.
Current knowledge about Omicron
in South Africa and around the world are conducting studies to better
understand many aspects of Omicron and will continue to share the
findings of these studies as they become available.
is not yet clear whether Omicron is more transmissible (e.g., more
easily spread from person to person) compared to other variants,
including Delta. The number of people testing positive has risen in
areas of South Africa affected by this variant, but epidemiologic
studies are underway to understand if it is because of Omicron or other
Severity of disease: It is not yet
clear whether infection with Omicron causes more severe disease
compared to infections with other variants, including
Delta. Preliminary data suggests that there are increasing rates of
hospitalization in South Africa, but this may be due to increasing
overall numbers of people becoming infected, rather than a result of
specific infection with Omicron. There is currently no information to
suggest that symptoms associated with Omicron are different from those
from other variants. Initial reported infections were among university
students—younger individuals who tend to have more mild disease—but
understanding the level of severity of the Omicron variant will take
days to several weeks. All variants of COVID-19, including the Delta
variant that is dominant worldwide, can cause severe disease or death,
in particular for the most vulnerable people, and thus prevention is
Effectiveness of prior SARS-CoV-2 infection
evidence suggests there may be an increased risk of reinfection with
Omicron (ie, people who have previously had COVID-19 could become
reinfected more easily with Omicron), as compared to other variants of
concern, but information is limited. More information on this will
become available in the coming days and weeks.
Effectiveness of vaccines:
WHO is working with technical partners to understand the potential
impact of this variant on our existing countermeasures, including
vaccines. Vaccines remain critical to reducing severe disease and death,
including against the dominant circulating variant, Delta. Current
vaccines remain effective against severe disease and death.
Effectiveness of current tests: The
widely used PCR tests continue to detect infection, including infection
with Omicron, as we have seen with other variants as well. Studies are
ongoing to determine whether there is any impact on other types of
tests, including rapid antigen detection tests.
Effectiveness of current treatments:
Corticosteroids and IL6 Receptor Blockers will still be effective for
managing patients with severe COVID-19. Other treatments will be
assessed to see if they are still as effective given the changes to
parts of the virus in the Omicron variant.
the present time, WHO is coordinating with a large number of
researchers around the world to better understand Omicron. Studies
currently underway or underway shortly include assessments of
transmissibility, severity of infection (including symptoms),
performance of vaccines and diagnostic tests, and effectiveness of
WHO encourages countries to contribute the collection and sharing of hospitalized patient data through the WHO COVID-19 Clinical Data Platform to rapidly describe clinical characteristics and patient outcomes.
information will emerge in the coming days and weeks. WHO’s TAG-VE will
continue to monitor and evaluate the data as it becomes available and
assess how mutations in Omicron alter the behaviour of the virus.
Recommended actions for countries
Omicron has been designated a Variant of Concern, there are several
actions WHO recommends countries to undertake, including enhancing
surveillance and sequencing of cases; sharing genome sequences on
publicly available databases, such as GISAID; reporting initial cases or
clusters to WHO; performing field investigations and laboratory
assessments to better understand if Omicron has different transmission
or disease characteristics, or impacts effectiveness of vaccines,
therapeutics, diagnostics or public health and social measures. More
detail in the announcement from 26 November.
should continue to implement the effective public health measures to
reduce COVID-19 circulation overall, using a risk analysis and
science-based approach. They should increase some public health
and medical capacities to manage an increase in cases. WHO is
providing countries with support and guidance for both readiness and
In addition, it is vitally important that
inequities in access to COVID-19 vaccines are urgently addressed to
ensure that vulnerable groups everywhere, including health workers and
older persons, receive their first and second doses, alongside equitable
access to treatment and diagnostics.
Recommended actions for people
most effective steps individuals can take to reduce the spread of the
COVID-19 virus is to keep a physical distance of at least 1 metre from
others; wear a well-fitting mask; open windows to improve ventilation;
avoid poorly ventilated or crowded spaces; keep hands clean; cough or
sneeze into a bent elbow or tissue; and get vaccinated when it’s their
WHO will continue to provide updates as more
information becomes available, including following meetings of the
TAG-VE. In addition, information will be available on WHO’s digital and
social media platforms.
Source: World Health Organization Website