2025-02-05-世界卫生组织-COVID-19_Global_Risk_Assessment_29页_664kb

COVID-19 Global Risk Assessment Summary (31 December 2024)

Core Content

The World Health Organization (WHO) conducted a global risk assessment for COVID-19 as of 31 December 2024, concluding that the global public health risk remains high, although the impact on human health has decreased compared to earlier years. Confidence in the available information is moderate, largely due to reduced surveillance activities and limited data reporting.

Main Points

1. Global Public Health Risk

• Overall Risk: High
• Confidence in Information: Moderate

The risk associated with SARS-CoV-2 remains high, but the overall impact on human health has decreased over time due to:

• High population immunity from infection, vaccination, or both
• Similar virulence of currently circulating JN.1 sublineages to previous Omicron sublineages
• Improved clinical case management and diagnostic testing

However, uncertainties persist, especially in regions affected by protracted crises and where surveillance is limited.

2. Virus Circulation and Mortality

• SARS-CoV-2 continues to circulate at significant levels, as evidenced by sentinel test positivity and wastewater surveillance.
• Case reports have declined, but this is likely due to reduced testing and data reporting, not a true decline in circulation.
• Estimated global confirmed cases: Over 776 million as of 27 October 2024
• Estimated global deaths: Over 7 million, with excess mortality estimates at least three times higher
• Weekly deaths: Declined from over 2300 in Q1 2024 to 1270 in Q3 2024
• Most at Risk Groups: Individuals aged 65+, those with underlying conditions, pregnant women, and unvaccinated individuals

3. Vaccine Coverage and Effectiveness

• Global Vaccine Coverage:
  • 67% of the population has received a complete primary series
  • 32% have received at least one booster dose
• High-risk Groups:
  • 83% of older adults (158 Member States) have received a primary series
  • 61% of older adults have received a booster
  • 89% of health and care workers have received a primary series
  • 31% have received a booster
• Vaccine Uptake in 2024:
  • Older adults: 1.68% uptake
  • Health and care workers: 0.96% uptake
• Vaccine Effectiveness:
  • Vaccines with WHO EUL/PQ remain effective against severe disease and death
  • Monovalent JN.1 vaccines are recommended for future formulations
  • No studies have yet been conducted on monovalent JN.1 vaccine effectiveness

4. Post-COVID-19 Condition (PCC)

• Approximately 6% of symptomatic infections develop PCC
• 15% of those with PCC have persistent symptoms up to 12 months
• Vaccination reduces the risk of PCC
• Understanding of PCC is still limited, affecting long-term care strategies

5. Variant Surveillance

• Circulating Variants:
  • JN.1 and its descent lineages make up 99.5% of all variants
  • BA.2.86 and JN.1 have immune escape properties but not increased severity
• Variants Under Monitoring (VUMs):
  • KP.2, KP.3, KP.3.1.1, JN.1.7, JN.1.18, LB.1, XEC
• Variants of Interest (VOIs):
  • BA.2.86 and JN.1
• Surveillance Challenges:
  • Reduced genomic sequencing and data submission
  • Wastewater surveillance is now the main method for monitoring variants
  • Limited data on variant impact and vaccine protection

6. Risk Assessment Questions and Outcomes

7. Risk Scenarios

• Base Case: Continued virus evolution with reduced severity, but potential for periodic transmission spikes
• Best Case: Future variants are less severe, and current vaccines remain effective
• Worst Case: Emergence of a more virulent and transmissible variant that overwhelms health systems
• Reset Case: Emergence of a completely new SARS-CoV-2 virus, requiring new vaccines and strategies

8. Strategic Framework and Recommendations

• WHO has transitioned from quarterly to bi-annual risk assessments
• The Strategic Preparedness, Readiness and Response Plan (SPRP) 2023-2025 focuses on integrating pandemic response into broader public health systems
• Standing Recommendations to Member States include:
  • Revising national plans and policies
  • Sustaining collaborative surveillance
  • Reporting data to WHO or open sources
  • Continuing vaccination based on WHO SAGE and national priorities
  • Supporting research for prevention and control

Key Information

• Global Surveillance Decline: Only 25% of countries report hospitalizations and 15% report ICU admissions
• Test Positivity and Wastewater Data: SARS-CoV-2 cases are estimated to be 2-19 times higher than reported
• Vaccine Uptake Gaps: Low in 2024, especially in low- and middle-income countries
• Future Risks: Possible emergence of more severe variants, and the need for ongoing vaccine composition updates
• WHO Actions:
  • Encouraging integration of SARS-CoV-2 into routine health services
  • Promoting co-administration with seasonal influenza vaccines
  • Working on new mortality estimates including 2022-2024 data

Conclusion

Despite the overall decline in the impact of SARS-CoV-2 on global health, the risk remains high due to ongoing virus evolution, limited surveillance, and low vaccine uptake in key populations. WHO emphasizes the need for sustained surveillance, improved vaccine coverage, and continued integration of pandemic response into broader public health systems to manage the ongoing threat of SARS-CoV-2.