Bibliographic information
GuidelineWHO guideline on public health and social measures for mitigating the risk and impact of epidemic and pandemic influenza
Year of Publication2026
Issuing InstitutionWorld Health Organization
Recommendation
New
WHO suggests considering restrictions on gatherings to reduce the transmission of influenza viruses in the community during influenza epidemics and pandemics.
Recommended in favor
Conditional
Certainty of evidence
Very low
Notes and Remarks
- Influenza viruses are transmitted between individuals through the air (that is, through inhalation or the direct deposition of infectious respiratory particles on the facial mucosa) and to a lesser extent through indirect contact (that is, through fomites) (333). As mass gatherings and crowded areas tend to increase person-to-person close contact, measures that reduce such contact could potentially reduce the community transmission of influenza (333).
- A risk-based approach based on the three steps of risk evaluation, risk mitigation and risk communication to inform the decision to restrict, modify, postpone, cancel or proceed with the holding of any gathering should be applied in the decision-making process.
- Decision-making process for holding, modifying, postponing or cancelling gatherings during influenza epidemics and pandemics should be risk-based, with an emphasis placed on risk assessment, risk mitigation and risk communication. Risk assessment should involve all relevant stakeholders, including national and local health authorities, as well as event organizers.
- In the decision-making process, aspects such as indoor versus outdoor gatherings, types of activity (for example, singing), timing of the intervention (early in the pandemic versus late) and prevalence of the infection should be taken into account.
- Strategies to reduce risk during gatherings (for example, limitations on the size of gatherings, pre-event testing and mask wearing) should be considered based on pandemic severity, the potential for influenza transmission in these settings and the desired transmission-related outcomes.
- There is a risk that very stringent restrictions could push gatherings underground, as was seen during the COVID-19 pandemic, which may undermine efforts to reduce virus transmission.