This report summarizes SAGE discussions, conclusions, and recommendations. All recommendations were made using evidence-based methods.
The SAGE meeting in March 2024 celebrated the achievements of the Expanded Programme on Immunization (EPI). A modelling study published in May 2024, estimated that since the EPI was established 50 years ago, 154 million lives have been saved through immunization efforts against 14 vaccine-preventable diseases. Of the lives saved, measles accounts for 60%; 40% of the reduction in infant mortality since 1974 can be attributed directly to vaccination.
With these achievements of EPI in mind, this report reflects on the current context, the status of vaccines and immunization, and a vision for maximizing the benefits of immunization in the future.
Immunization Agenda 2030 (IA2030)
SAGE recognized the longstanding challenges to achieving high and equitable vaccination coverage and that the negative impact of the COVID-19 pandemic lingers. Nevertheless, new vaccine introductions increase the opportunity for saving more lives and there are examples where the introduction of new vaccines increased demand for vaccination and contributed to increasing routine immunization coverage.
It was recognized that strengthening health systems, including addressing the shortfalls, capacity and motivation of the health workforce, is beyond the mandates of immunization programs alone and encouraged a collaborative approach between national health programs with coordinated support from bilateral and multilateral development partners.
Respiratory syncytial virus
Both nirsevimab and the RSVPreF vaccine have received market authorization in more than 40 countries. There has been a global access commitment by the manufacturer to supply RSVPreF at an affordable price to low-income countries (LICs) and LMICs through public sector purchases, including through GAVI. Currently, there is no such price commitment enabling LICs and LMICs access to nirsevimab.
Given the global burden of RSV disease, SAGE recommended that all countries introduce products for the prevention of severe RSV disease in infants. Decisions to use maternal RSVPreF vaccination and/or nirsevimab should consider cost, financing, supply, anticipated coverage and feasibility of implementation within the existing health system.
Poliomyelitis
SAGE expressed concern about a significant increase in paralytic poliomyelitis cases caused by wild poliovirus type 1 (WPV1) detected in the endemic zones of Afghanistan and Pakistan in 2024. They also expressed concern about at the continuing detection of circulating vaccine-derived poliovirus 2 or cVDPV type 2 (cVDPV2), which is likely to continue beyond 2024. SAGE reiterated the need for timely responses with nOPV2 campaigns, with >90% coverage in and around the areas of emergence.
Vaccine SAGE experts reiterated that routine polio vaccine coverage of ≥95% is essential for poliovirus eradication. The importance of identifying and vaccinating zero-dose children in endemic and outbreak-affected areas and enhancing environmental surveillance for polioviruses was emphasized.
Since many countries desire to switch to IPV-only schedules ahead of synchronized bOPV cessation, SAGE requested that WHO develop a risk-grading criteria framework to define eligibility for a safe transition ahead of bOPV cessation and to present it to SAGE in 2025. The criteria should encompass vaccine coverage, indicators for sanitation, population density and proximity to outbreak areas.
SAGE acknowledged the use of OPV as the primary tool for outbreak response because of its ability to elicit mucosal immunity. However, the suboptimal immunogenicity of OPV in low- and middle-income country settings where WPV1 or cVDPV outbreaks occur was recognized. Therefore, SAGE recommended the concomitant use of IPV and nOPV2 (bOPV if type 1 or type 3 viruses circulate) in initial outbreak response vaccination campaigns.
Recent genetic and safety data from a clinical trial of co-administration of nOPV2 and bOPV, and additional information from the field, show that the main attenuation determinants for nOPV2 remain intact. Based on these data, SAGE revised its earlier recommendation and recommended concomitant administration of nOPV2 and bOPV as an option in areas where poliovirus types 1 and 2 co-circulate. IPV may be added to concomitant nOPV and bOPV administration.
Rubella and congenital rubella syndrome
As of 2023, rubella elimination has been achieved in 99 (51%) countries. Despite this progress, the remaining 19 countries without access to rubella-containing vaccines (RCV) continue to serve as reservoirs for the virus, with sustained transmission, including to other countries. These countries – all but 3 of which are LICs – account for most of the global burden of congenital rubella syndrome (CRS). The universal use of RCV would significantly advance global equity goals.
Without rubella vaccination, demographic trends such as lower birth rates leading to older age of infection are expected to increase the future risk of CRS.
Universal RCV introduction is expected to substantially reduce overall rubella prevalence and accelerate regional elimination efforts.
Based on the evidence provided, SAGE recommended lifting the requirement for ≥80% MCV coverage through routine immunization or campaigns before RCV introduction.
SAGE also reinforced the existing WHO policy for regular follow-up campaigns in all countries until they reach ≥90% routine coverage with measles and rubella vaccines.
Mpox and avian influenza
Mpox
A Global Strategic Preparedness and Response Plan has been developed, which includes a comprehensive approach addressing surveillance, case management, safe and scalable home care, communication and community protection. The recommended countermeasures include vaccines, therapeutics, diagnostics and other relevant health products. The first phase of the strategy is to interrupt known chains of transmission, then expand protection to limit the potential spread in affected communities and, finally, increase population immunity in areas at risk for future outbreaks or outbreak expansion.
As more vaccines become available, preventive vaccination will be considered as per the recommendations in the 2024 WHO vaccine position paper. The first mpox vaccine (MVA-BN) was prequalified in September 2024 for use in adults aged ≥18 years; discussions are ongoing to have the LC16 vaccine emergency use listed by WHO. SAGE will continue to monitor the situation and update recommendations as required.
Avian Influenza
Human cases have been detected across all WHO regions. Continuous monitoring and response are in place for animal influenza viruses with zoonotic potential. A recent consultation was held to look at options for the use of an H5N1 vaccine in the interpandemic phase; SAGE will be presented with the outcomes of this consultation in due course.
COVID-19
Vaccine demand and uptake have dropped significantly in 2024. (editorial note: due to vaccine fatigue and hesitancy)
Post-COVID conditions include a constellation of post-acute and long-term health effects caused by SARSCoV-2. At the end of 2023, the cumulative number of such cases was estimated to be 409 million, with a point prevalence of 6–7% in adults and 1% in children. Three symptom clusters, namely, persistent fatigue, cognitive problems and respiratory problems, have been reported. Reinfection can lead to post-COVID conditions or exacerbate existing symptoms. Recovery rates are low, although some therapeutics show promise. Vaccination appears to have a protective effect in reducing the likelihood of post-COVID conditions.
While recognizing the steep decline in vaccine demand, SAGE emphasized the importance of revaccinating high-priority groups as per the recommendations in the roadmap, with due consideration given to cost–effectiveness, opportunity costs and delivery challenges.
SAGE also recommended that countries consider co-administering COVID-19 vaccines with seasonal influenza vaccines or other respiratory vaccines when epidemiologically appropriate and programmatically feasible.
Furthermore, SAGE underscored the importance for all countries to have access to variant-adapted monovalent COVID-19 vaccines.
WHO is currently working towards developing a comprehensive position paper on COVID-19 vaccines, which is expected to be published in 2025 and replace the current interim recommendations.
