On November 26, 2021, The WHO has classified B.1.1.529 as a variant of concern, called Omicron, on the advice of the WHO Technical Advisory Group on Virus Evolution (TAG-VE). This decision was based on evidence submitted to 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 the disease it causes. Here is a summary of what is currently known.
Current knowledge about Omicron
Researchers in South Africa and around the world are conducting studies to better understand many aspects of Omicron and will continue to share the results of these studies as they become available.
portability: It is not yet clear whether omicron is more transmissible (eg, spreads more easily from person to person) than other variants, including delta. The number of people testing positive for the virus has increased in areas of southern Africa affected by this variant, but epidemiological studies are underway to understand whether this is due to Omicron or other factors.
the severity of the disease: It is not yet clear whether omicron infection causes more serious disease compared to infection with other variants, including delta. Preliminary data suggest that there are increasing rates of hospitalization in South Africa, but this may be due to increased overall numbers of people becoming infected, rather than as a result of omicron-specific infections. There is currently no information to suggest that the symptoms associated with Omicron are different from those of the other variants. The primary infections reported were among college students – younger individuals who tend to have milder disease – but understanding the severity level of the Omicron variant will take days to several weeks. All variants of COVID-19, including the worldwide dominant delta variant, can cause severe illness or death, particularly for the most vulnerable, so prevention is always key.
Previous infection efficacy of SARS-CoV-2
Preliminary evidence suggests that there may be an increased risk of reinfection with Omicron (eg, people who have previously been infected with COVID-19 can be re-infected more easily with Omicron), compared to other variables of concern, but information is limited. More information on this will be available in the coming days and weeks.
Vaccine efficacy: The World Health Organization is working with technical partners to understand the potential impact of this alternative on our current countermeasures, including vaccines. Vaccines remain essential to reduce severe illness and death, including against the dominant circulating virus, Delta. Current vaccines remain effective against severe disease and death.
Effectiveness of current tests: The widely used polymerase chain reaction (PCR) tests continue to detect infections, including omicron infection, as we have seen with other variants as well. Studies are underway to determine if there is any effect on other types of tests, including rapid antigen detection tests.
Effectiveness of current treatmentsCorticosteroids and IL6 receptor blockers will continue to be effective in the management of patients with severe COVID-19. Other treatments will be evaluated to see if they are still effective given changes in parts of the virus in the Omicron variant.
Studies are underway
At present, the World Health Organization is coordinating with a large number of researchers around the world to better understand Omicron. Studies currently underway or soon underway include assessments of transmissibility, severity of infection (including symptoms), performance of vaccines and diagnostic tests, and efficacy of treatments.
WHO encourages countries to contribute to the collection and sharing of hospital patient data through the WHO COVID-19 Clinical Data Platform in order to quickly describe clinical characteristics and patient outcomes.
More information will appear in the coming days and weeks. WHO’s TAG-VE will continue to monitor and evaluate data as it becomes available and assess how mutations in Omicron alter the behavior of the virus.
Recommended actions for countries
Because Omicron has been classified as a variant of concern, there are several actions WHO recommends countries take, including strengthening surveillance and case sequencing; sharing of genome sequences in publicly available databases, such as GISAID; Notify WHO of initial cases or clusters; Conduct field investigations and laboratory evaluations to better understand whether Omicron has different characteristics of transmission or disease, or affects the efficacy of vaccines, treatments, diagnosis, or public health and social measures. More details in the November 26 announcement.
Countries must continue to implement effective public health measures to reduce the spread of COVID-19 in general, using risk analysis and a science-based approach. They should increase some general health and medical capabilities to manage the increase in cases. WHO provides countries with support and guidance regarding preparedness and response.
In addition, it is critically important to urgently address inequalities in access to COVID-19 vaccines to ensure that vulnerable groups everywhere, including health workers and the elderly, receive their first and second doses, along with equitable access to treatment and diagnosis.
Recommended actions for people
The most effective steps that individuals can take to reduce the spread of the COVID-19 virus is to maintain a physical distance of at least one meter from others; Wear a suitable mask. open windows to improve ventilation; avoid poorly ventilated or crowded places; keep hands clean coughing or sneezing into an elbow or a bent tissue; And vaccinate when it’s their turn.
WHO will continue to provide updates as more information becomes available, including at subsequent TAG-VE meetings. In addition, the information will be available on WHO’s digital and social media platforms.