GUIDING PRINCIPLES FOR IMMUNIZATION ACTIVITIES DURING THE COVID-19 PANDEMIC
Due to the global circulation of the virus causing COVID-19 and the current pandemic, there is the risk of disruption to routine immunization activities due to both COVID-19 related burden on the health system and decreased demand for vaccination because of physical distancing requirements or community reluctance. Disruption of immunization services, even for brief periods, will result in increased numbers of susceptible individuals and raise the likelihood of outbreak-prone vaccine-preventable diseases (VPDs) such as measles.1 Such VPD outbreaks may result in increased morbidity and mortality predominantly in young infants and other vulnerable groups, which can cause a greater burden on health systems already strained by the COVID-19 response. The high potential for VPD outbreaks makes it imperative for countries to maintain continuity of immunization services wherever services can be conducted under safe conditions. Prior disease outbreaks and humanitarian emergencies have underscored the importance of maintaining essential health services such as immunization, and effectively engaging communities in planning and service delivery. 2,3 Yet the complexity and global reach of the COVID-19 response with respect to mandatory physical distancing (also referred to as social distancing) and economic impact on households is unprecedented for public health.
This document provides guiding principles and considerations to support countries in their decision-making regarding provision of immunization services during the COVID-19 pandemic and is endorsed by the WHO’s Strategic Advisory Group of Experts on Immunization. It is complemented by a range of WHO technical materials on response and mitigation measures for COVID-19.4 Each country will need to make individual risk assessments based on the local dynamics of COVID-19 transmission, immunization and health system characteristics, and current VPD epidemiology in their setting.
GUIDING PRINCIPLES 1. Immunization is a core health service that should be prioritized for the prevention of communicable diseases and safeguarded for continuity during the COVID-19 pandemic, where feasible.5 Immunization delivery strategies may need to be adapted and should be conducted under safe conditions, without undue harm to health workers, caregivers and the community.6
- VPD surveillance should be maintained and reinforced to enable early detection and management of VPD cases, and where feasible, contribute to surveillance of COVID-19.
- National authorities will need to continuously monitor the dynamics of COVID-19 in their country or region. National Immunization Technical Advisory Groups (NITAGs) have an important role in providing advice with respect to the maintenance, adaptation, suspension and/or reinstatement of immunization services.
- If provision of immunization services is negatively impacted by COVID-19, countries will need to design strategies for catch-up vaccination for the period post COVID-19 outbreak and make plans which anticipate a gradual recovery. Implementation of catch-up will require strategies to track and follow-up with individuals who missed vaccinations, assess immunity gaps, and re-establish community demand. Innovation and creativity will be required.
- Based on the current understanding of transmission of the COVID-19 virus and recommendations for physical distancing, mass vaccination campaigns should be temporarily suspended. Countries should monitor and re-evaluate at regular intervals the necessity for delaying mass vaccination campaigns.
- The conduct of outbreak response mass vaccination campaigns will require a careful risk-benefit analysis on a case-by-case basis, assessing risks of a delayed response against the risks associated with an immediate response, both in terms of morbidity and mortality for the VPD and the potential impact of further transmission of the COVID-19 virus.
- Where feasible, influenza vaccination of health workers, older adults, and pregnant women is advised.7
CONSIDERATIONS FOR ROUTINE IMMUNIZATION AND VPD SURVEILLANCE
- The decision to maintain immunization services will be influenced by local mandates for physical distancing and guided by health system context, the local burden of VPDs, the status and anticipated status of local COVID-19 transmission (classified as no cases, sporadic, clusters, or community transmission), and factors such as population demographics and migration patterns.
- Where health system capacity is intact and essential health services are operational (e.g., adequate human resources, adequate vaccine supply), fixed site immunization services and VPD surveillance should be executed while maintaining physical distancing measures and appropriate infection control precautions, equipped with the necessary supplies for those precautions.8
- The appropriateness of implementing alternative strategies (e.g. outreach or mobile services), as well as activities requiring community interaction for VPD surveillance, must be assessed in the local context and should be adapted to ensure the safety of the health workers and community. Innovative methods for vaccination delivery should be explored to optimize service delivery.
- Where the provision of limited services is feasible, immunization of vulnerable populations at increased risk of morbidity and mortality due to VPDs should be prioritized for vaccination against outbreak-prone diseases such as measles, polio, diphtheria and yellow fever.
CONSIDERATIONS FOR MASS VACCINATION CAMPAIGNS
- Based on the current understanding of the transmission modes of the COVID-19 virus and the recommended prevention measures of physical distancing, it is advised to temporarily suspend the conduct of mass vaccination campaigns due to the increased risk of promoting community circulation. Countries should monitor and re-evaluate at regular intervals the necessity for the delay of mass vaccination campaigns.
- Under circumstances of a VPD outbreak, the decision to conduct outbreak response mass vaccination campaigns will require a risk-benefit assessment on a case by case basis and must factor in the health system’s capacity to effectively conduct a safe and high-quality mass campaign in the context of the COVID-19 pandemic. The assessment should evaluate the risks of a delayed response against the risks associated with an immediate response, both in terms of morbidity and mortality for the VPD and the potential impact of further transmission of the COVID-19 virus.
- Should an outbreak response vaccination campaign be pursued, stringent measures are required to uphold standard and COVID-19 infection prevention and control, adequately handle injection waste, protect health workers and safeguard the public.
- Should an outbreak response vaccination campaign be delayed, a periodic assessment based on local VPD morbidity and mortality, as well as regional and international epidemiology will be required to evaluate risk of further delay.
CONSIDERATION FOR RE-ESTABLISHING IMMUNIZATION SERVICES
- In circumstances where immunization services must be diminished or suspended, countries should reinstate and reinvigorate immunization services at the earliest opportunity to close immunity gaps, once reduced local transmission of the COVID-19 virus permits primary health care services to resume. *If resources for catch-up are limited, catch-up immunization activities should place priority on outbreak-prone VPDs such as measles, polio, diphtheria, and yellow fever.
- Countries should implement effective communication strategies and engage with communities to allay concerns, enhance community linkages and re-establish community demand for vaccination.
SOURCES This content is made available courtesy of the WHO. WHO reference number: WHO/2019-nCoV/immunization_services/2020.1
- Suk et al. Post-Ebola Measles Outbreak in Lola,Guinea, January–June 2015. Emerging Infectious Diseases. 2016; 22(6):1106-1108.
- Vaccination in Acute Humanitarian Emergencies: A Framework for decision-making https://www.who.int/immunization/documents/who_ivb_17.03/en/
- COVID-19: Strategic Planning and Operational Guidance for Maintaining Essential Health Services During an Outbreak. 20 March 2020. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance
- WER, 23 November 2012, 23 No. 47, 2012, 87, 461–476 https://www.who.int/wer/2012/wer8747.pdf?ua=1