2021-06-24-世界卫生组织-WHO_SAGE_roadmap_for_prioritizing_uses_of_COVID-19_vaccines_in_the_context_of_limited_supply_draft_document_31页_506kb

WHO SAGE Roadmap for Prioritizing Uses of COVID-19 Vaccines in the Context of Limited Supply Summary

Core Content

The WHO SAGE Roadmap for Prioritizing Uses of COVID-19 Vaccines in the Context of Limited Supply is a strategic document designed to guide countries in making informed decisions about vaccine distribution when supply is limited. It outlines a three-step process that includes a Values Framework, a Prioritization Roadmap, and vaccine-specific recommendations. The Roadmap was initially developed in November 2020 and updated on 29 June 2021 to incorporate new data and evolving pandemic conditions.

Main Points

Rationale

• The Roadmap was created to help countries prioritize vaccine use in a pragmatic and ethical manner, given the limited and unreliable vaccine supply in most middle- and low-income countries.
• It is not intended for global allocation; this is managed by the COVAX Facility.
• The Values Framework serves as the foundation, emphasizing principles such as equal respect, equity, and reciprocity.

Process of Development

• The Roadmap was developed by the SAGE Working Group on COVID-19 Vaccines, with input from RITAG chairs, NITAG members, and WHO Secretariat.
• It was updated in June 2021 to reflect new evidence, including vaccine efficacy against VOCs, transmission dynamics, and public health strategies.
• The final version was reviewed and endorsed by SAGE.

Guiding Considerations

• The Roadmap must remain aligned with the WHO SAGE Values Framework.
• It is designed to be clear and concise for use in regional and national discussions.
• It will be revisited regularly as new information emerges and in ongoing dialogue with RITAGs and NITAGs.
• Countries are encouraged to refer to the Global Vaccination Strategy for broader goal-setting.

Key Assumptions

• All vaccines considered have received emergency use listing or full regulatory approval.
• Vaccines are assumed to be effective against VOCs, especially after two doses.
• Non-pharmaceutical interventions remain in place during vaccine rollout.
• The Roadmap does not account for natural immunity or seropositivity rates.
• Chronic morbidity and long-term sequelae are not yet included due to limited evidence.
• Risk of severe disease is closely correlated with risk of death, and reciprocity is a key ethical principle.

Epidemiologic Setting Scenarios

Three main epidemiologic settings are identified:

1. Community Transmission: Ongoing spread of the virus in the population.
2. Sporadic Cases or Clusters: Limited spread with potential for further outbreaks.
3. No Cases: Transmission has been stopped through public health measures.

Each setting informs the public health strategy and priority-use group selection.

Vaccine Supply Scenarios

Three stages of vaccine supply are outlined:

1. Stage I: Very limited vaccine availability (1–10% of population).
2. Stage II: Limited vaccine availability (11–20% of population).
3. Stage III: Moderate vaccine availability (21–50% of population).

These stages determine the priority-use groups and the strategy for vaccine deployment.

Priority Uses of Vaccines

The Roadmap identifies priority-use groups based on epidemiologic settings and vaccine supply stages. These groups are prioritized to align with the Values Framework and to maximize public health impact.

• Stage Ia: Health workers at high to very high risk of infection and transmission.
• Stage Ib: Older adults (age-based risk).
• Stage II: Groups with comorbidities or health states at significantly higher risk of severe disease or death.
• Stage III: Social/employment groups at elevated risk due to inability to physically distance.

Staging and Group Size

• Staging is sequential, meaning that Stage I groups are prioritized before Stage II and Stage III.
• Group size is a key factor in assigning priority-use groups, but within a stage, groups are not ranked.
• Countries may need to select specific groups within a stage if vaccine supply is insufficient to cover all assigned groups.

Special Considerations

Gender

• The Roadmap does not use gender to prioritize vaccine use to avoid exacerbating existing gender-based inequities.
• It emphasizes equal respect for both men and women in all priority-use groups.

Pregnant Women

• Pregnant women are included in Stage II as part of the group with comorbidities or health states at higher risk.
• They are prioritized due to the increased risk of severe disease and adverse neonatal outcomes.
• Safety data for pregnant women is limited but suggests no harmful effects from vaccines.
• Antibodies are transported to infant cord blood and breast milk, indicating maternal and neonatal protection.

Children

• Children are included in Stage III due to their increased risk of transmission and impact on social and economic functions.
• They are considered as part of social/employment groups that cannot effectively distance themselves.

Comorbidities

• Groups with comorbidities that increase the risk of severe disease are prioritized in Stage II.
• These include individuals with HIV, diabetes, hypertension, and other conditions that increase vulnerability.

Community Engagement and Communication

• The Roadmap emphasizes the importance of community engagement, effective communication, and legitimacy in vaccine prioritization.
• These elements are crucial to ensure public trust and ethical decision-making.

Conclusion

The WHO SAGE Roadmap provides a structured and ethical approach to vaccine prioritization under limited supply. It supports national and regional decision-making by integrating epidemiologic data, vaccine characteristics, and ethical principles. The document is dynamic, with plans for future updates to reflect new evidence and evolving pandemic conditions. It encourages equitable and pragmatic distribution to optimize health, socioeconomic, and equity outcomes.