Evidence-based recommendations on non-pharmaceutical interventions to reduce influenza transmission in community settings for national and local health authorities.
What this guideline saysGMJ summary
This WHO guideline provides 21 evidence-based recommendations on public health and social measures (PHSM) to reduce transmission of influenza viruses during epidemics and pandemics. PHSM are non-pharmaceutical interventions implemented by individuals, communities and governments to prevent or slow disease spread when vaccines and antivirals may be unavailable or in short supply.
The guideline covers personal protection measures (hand hygiene, mask wearing, respiratory etiquette), environmental measures (ventilation, surface cleaning), active case-finding (isolation, contact tracing), social measures (school and workplace adaptations, restrictions on gatherings) and travel-related measures. Recommendations are graded using GRADE methodology based on systematic reviews of evidence from influenza studies and, where relevant, COVID-19 pandemic data.
Strong recommendations include: performing hand hygiene, practising respiratory hygiene and cough etiquette, increasing ventilation, voluntary home isolation of symptomatic individuals, and providing travel health advice. The guideline emphasizes that PHSM must be implemented with full respect for human rights, equity considerations, and proportionality to the assessed severity of the outbreak, using the pandemic influenza severity assessment (PISA) framework.
Key pointsfor clinicians
- Hand hygiene with soap and water (or alcohol-based handrub when hands not visibly soiled) is recommended to reduce influenza transmission (strong recommendation, moderate certainty evidence)
- Symptomatic or influenza-positive individuals should wear masks when in contact with others; universal mask wearing in crowded indoor settings suggested during high/extraordinary severity pandemics (conditional recommendation, moderate certainty)
- Voluntary home isolation of symptomatic/infected individuals recommended in all circumstances; mandatory isolation only suggested in exceptional circumstances of high/extraordinary severity (strong/conditional recommendations, very low certainty)
- Increase mechanical or natural ventilation in households and non-residential buildings to minimum 10 litres per second per person in non-residential settings (strong recommendation, low certainty)
- Contact tracing not recommended except for first cases of emerging strain to characterize disease; short serial interval makes it inefficient (conditional recommendation against, very low certainty)
- Proactive school closure and workplace measures (including remote work) suggested only during pandemics of high or extraordinary severity (conditional recommendation, very low certainty)
- Travel restrictions including border closures not recommended; travel health advice should be provided (conditional recommendation against / strong recommendation for, very low certainty)
- Syndromic entry/exit screening at points of entry not recommended; upon-arrival quarantine not recommended (strong/conditional recommendations against, very low certainty)
Summary of recommendationsextracted from the guideline
| Measure | Recommendation | Certainty | Strength |
|---|---|---|---|
| Hand hygiene | Recommended to reduce transmission | Moderate | Strong for |
| Mask wearing | Symptomatic individuals wear masks; all in crowded indoor settings during high/extraordinary severity | Moderate | Conditional for |
| Respiratory hygiene/cough etiquette | Recommended for individuals not wearing masks | Moderate | Strong for |
| Air purification | Not recommended in community settings | Moderate | Strong against |
| Modifying indoor humidity | Not recommended | Very low | Strong against |
| Surface cleaning/disinfection | Suggested to reduce transmission | Low | Conditional for |
| Ventilation | Recommended to increase mechanical or natural ventilation | Low | Strong for |
| Contact tracing | Not recommended except for first cases of emerging strain | Very low | Conditional against |
| Isolation – voluntary | Recommended for symptomatic/infected individuals | Very low | Strong for |
| Isolation – mandatory | Suggested only in exceptional circumstances (high/extraordinary severity) | Very low | Conditional for |
| Mass testing | Not recommended in community settings | Very low | Conditional against |
| Voluntary self-quarantine | Suggested for exposed individuals during high severity | Very low | Conditional for |
| Indoor hospitality/recreation measures | Not recommended | Very low | Conditional against |
| Restrictions on gatherings | Suggested to consider | Very low | Conditional for |
| School measures/closures | Measures suggested as alternative to closure; proactive closure only for high/extraordinary severity | Very low | Conditional for |
| Stay-at-home provisions | Not recommended | Low | Conditional against |
| Workplace measures/closures | Remote work encouraged; closures only for high/extraordinary severity | Very low | Conditional for |
| Entry/exit screening | Not recommended | Very low | Strong against |
| Travel advice | Recommended to inform individuals of risks | Very low | Strong for |
| Travel restrictions | Not recommended | Very low | Conditional against |
| Upon-arrival quarantine | Not recommended | Very low | Conditional against |
What changed in this edition
- Expanded from 2019 guidance to include new PHSM widely implemented during COVID-19 pandemic: air purification, mass testing, indoor hospitality/recreation measures, stay-at-home provisions, and upon-arrival quarantine
- Updated evidence base through systematic reviews incorporating COVID-19 pandemic data where relevant to influenza transmission
- Strengthened emphasis on equity and human rights considerations throughout PHSM design and implementation
- Added pandemic influenza severity assessment (PISA) framework for guiding selection and timing of interventions based on outbreak severity levels
ApplicabilityGeorgia and the region
For Georgia and the South Caucasus region, this guideline is highly relevant given limited pandemic preparedness resources and seasonal influenza burden. National influenza pandemic preparedness plans should integrate these PHSM recommendations, prioritizing low-cost, high-impact measures (hand hygiene, respiratory etiquette, ventilation) that can be implemented immediately. Countries should assess capacity for voluntary isolation support (paid sick leave, social protection), ventilation standards in schools and public buildings, and communication infrastructure for risk communication and community engagement. Regional collaboration through mechanisms like the Caucasus Field Epidemiology and Laboratory Training Program can strengthen surveillance and early response capacity. Special attention needed for vulnerable populations including rural communities, internally displaced persons, and those in crowded housing with limited access to water/sanitation. Pre-positioning RCCE strategies and establishing legal frameworks that respect human rights while enabling proportionate responses to different PISA severity levels should be national priorities.
Questions this guideline answers
When should highly disruptive PHSM like school closures or workplace closures be implemented?
The guideline recommends proactive school closure and workplace closures only during influenza pandemics of high or extraordinary severity as assessed by the PISA framework. These measures should be time-limited, proportionate to the assessed risk, implemented alongside social protection policies (e.g., paid sick leave), and relaxed when community transmission and health system impact reduce to acceptable levels. School measures (e.g., hybrid learning, staggered schedules, physical distancing) should be considered as sustainable alternatives to full closure.
What is the role of mask wearing during an influenza pandemic?
Individuals who are symptomatic or have tested positive for influenza should wear medical masks at all times when in contact with others to reduce spread (source control). Universal mask wearing in crowded indoor settings is suggested only during pandemics of high or extraordinary severity. Mask wearing should be paired with education on proper use and is complementary to, not a replacement for, other measures. Medical masks should be prioritized for healthcare workers and high-risk individuals if supply is limited.
Why is contact tracing not recommended for influenza despite being used during COVID-19?
Contact tracing is not recommended for influenza (except for first cases of emerging strains) because influenza has a short serial interval (time between successive cases) making tracing inefficient, a significant proportion of asymptomatic infections limiting effectiveness, and it is highly resource-intensive that would quickly overwhelm public health systems. For COVID-19, the longer serial interval and pre-symptomatic transmission patterns made contact tracing more feasible and potentially effective, though still resource-intensive. For influenza, resources are better directed to other interventions like voluntary isolation support and risk communication.
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- Issuer
- World Health Organization
- Type
- Guideline
- Edition
- 1st edition, 2026
- Replaces
- Non-pharmaceutical public health measures for mitigating the risk and impact of epidemic and pandemic influenza, 2019
- Status
- Current
- Published
- 2026-05-27
- Languages
- English (original); translations expected
- Scope
- Public health and social measures (PHSM) for influenza epidemics and pandemics in community settings; excludes healthcare facility-specific measures and pharmaceutical interventions (vaccines, antivirals)
- Audience
- National and local health authorities, policy-makers, stakeholders in education and other sectors involved in PHSM decision-making and implementation during influenza outbreaks
- Pages
- 161
- Licence
- CC BY-NC-SA 3.0 IGO
- ISBN
- 978-92-4-011665-8
- Evidence
- GRADE-rated recommendations based on systematic reviews of randomized controlled trials, observational studies and simulation models; evidence from influenza studies supplemented with COVID-19 data where relevant
- Next review
- Not specified; guideline will be updated as new evidence emerges
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