The World Health Organization (WHO) has designated the variant B.1.1.529 a variant of concern (VOC), named Omicron, on the basis of advice from WHO’s Technical Advisory Group on Virus Evolution (hereafter referred to as TAG-VE) on 26 November 2021. Following the group’s announcement an increasing number of countries are introducing temporary travel measures, including temporarily prohibiting the arrival of international travellers from Southern African countries and others where the new variant is being detected, including from South Africa, which first reported the variant to WHO on 24 November 2021.
WHO commends South Africa and Botswana for their capacities in surveillance and sequencing and for the speed and transparency with which they notified and shared information with the WHO Secretariat on the Omicron variant in accordance with the International Health Regulations (2005) (IHR). These actions have allowed other countries to rapidly adjust their response measures in the context of the COVID-19 pandemic. WHO calls on all countries to follow the IHR (2005) and to show global solidarity in rapid and transparent information sharing and in a joint response to Omicron (as with all other variants), leveraging collective efforts to advance scientific understanding and sharing the benefits of applying newly acquired scientific knowledge and tools.
As noted in the WHO announcement, the Omicron variant has a large number of mutations, some of which are concerning. Preliminary evidence suggests an increased risk of reinfection with this variant as compared to other VOCs. Current SARS-CoV-2 polymerase chain reaction (PCR) diagnostics continue to be effective in detecting this variant.
It is expected that the Omicron variant will be detected in an increasing number of countries as national authorities step up their surveillance and sequencing activities. WHO is closely monitoring the spread of the Omicron variant, and studies are ongoing to understand more about these mutations and their impact on transmissibility, virulence, diagnostics, therapeutics and vaccines. The TAG-VE will continue to evaluate the Omicron variant, and WHO will communicate new findings with IHR States Parties and the public as needed.
While scientific research is underway to understand how the variant behaves, WHO advises the following:
- Countries should continue to apply an evidence-informed and risk-based approach when implementing travel measures in accordance with the IHR, including the latest Temporary Recommendations issued by the WHO Director-General on 26 October 2021 following the 9th Emergency Committee for COVID-19 and as recommended in the documents WHO policy and technical considerations for implementing a risk-based approach to international travel in the context of COVID-19 issued in July 2021.
- National authorities in countries of departure, transit and arrival may apply a multi-layered risk mitigation approach to potentially delay and/or reduce the exportation or importation of the new variant. Such measures may include screening of passengers prior to travelling and/or upon arrival, including via the use of SARS-CoV-2 testing or the application of quarantine to international travellers. These measures, nonetheless, need to be defined following a thorough risk assessment process informed by the local epidemiology in departure and destination countries and by the health system and public health capacities in the countries of departure, transit and arrival. All measures should be commensurate with the risk, time-limited and applied with respect to travellers’ dignity, human rights and fundamental freedoms, as outlined in the IHR (2005).
- Blanket travel bans will not prevent the international spread, and they place a heavy burden on lives and livelihoods. In addition, they can adversely impact global health efforts during a pandemic by disincentivizing countries to report and share epidemiological and sequencing data. All countries should ensure that the measures are regularly reviewed and updated when new evidence becomes available on the epidemiological and clinical characteristics of Omicron or any other VOC.
- Any travel-related risk mitigation measures should be part of an overall national response strategy which, for VOCs, includes the following, in line with the announcement published on 26 November 2021:
- enhancing surveillance and sequencing efforts to better understand circulating SARS-CoV-2 variants, not only among travellers, but also within the community
- submitting complete genome sequences and associated metadata to a publicly available database, such as GISAID
- reporting initial cases/clusters associated with VOC infection to WHO through the IHR mechanism
- where capacity exists and in coordination with the international community, performing field investigations and laboratory assessments to improve understanding of the potential impacts of the VOC on COVID-19 epidemiology and severity, effectiveness of public health and social measures, diagnostic methods, immune responses, antibody neutralization or other relevant characteristics
- continue to calibrate national public health and social measures according to the changing epidemiological situation and national systems’ capacities to reduce COVID-19 circulation overall, including at points of entry, using a risk-based and scientific approach .
- Since the beginning of the SARS-CoV-2 outbreak, WHO has been monitoring the international travel measures implemented by countries and sharing this information with National IHR Focal Points via the Event Information Site (EIS). As of 28 November 2021, 56 countries were reportedly implementing travel measures aimed at potentially delaying the importation of the new variant. Countries should continue sharing their public health rationale and relevant scientific information for additional health measures with WHO under the provisions of Article 43 of the IHR (2005).
- Essential international travel –including travel for emergency and humanitarian missions, travel of essential personnel, repatriations and cargo transport of essential supplies–should continue to be prioritized at all times during the COVID-19 pandemic.
- In addition, all travellers should be reminded to remain vigilant for signs and symptoms of COVID-19, to get vaccinated when it is their turn and to adhere to public health and social measures at all times and regardless of vaccination status, including by using masks appropriately, respecting physical distancing, following good respiratory etiquette and avoiding crowded and poorly ventilated spaces. Persons who are unwell, or who have not been fully vaccinated or do not have proof of previous SARS-CoV-2 infection and are at increased risk of developing severe disease and dying, including people 60 years of age or older or those with comorbidities that present increased risk of severe COVID-19 (e.g. heart disease, cancer and diabetes) should be advised to postpone travel to areas with community transmission.