Table of Contents
The World Health Organization (WHO) has provided important health recommendations for 2023, focusing on various vaccines and immunization programs. These recommendations aim to prevent diseases such as malaria, dengue, meningitis, and COVID-19. The WHO’s advice is based on extensive research and the expertise of its Strategic Advisory Group of Experts on Immunization (SAGE) and the Malaria Policy Advisory Group (MPAG). These recommendations were endorsed by the WHO Director-General after their recent biannual meeting held in September 2023.
Malaria Prevention for Children
The WHO has recommended a new vaccine called R21/Matrix-M for the prevention of malaria in children. This vaccine is the second malaria vaccine to be recommended by the WHO, following the RTS,S/AS01 vaccine recommendation in 2021. Both vaccines have been proven safe and effective in preventing malaria in children, and their widespread implementation is expected to have a significant impact on public health. Malaria is a mosquito-borne disease that disproportionately affects children in the African Region, causing nearly half a million deaths per year.
The demand for malaria vaccines is unprecedented, but the available supply of the RTS,S vaccine is limited. The addition of the R21 vaccine to the list of WHO-recommended malaria vaccines is expected to provide sufficient vaccine supply to benefit all children living in areas where malaria is a public health risk. This is a significant step towards achieving the WHO’s vision of a malaria-free future.
Dr Tedros Adhanom Ghebreyesus, the WHO Director-General, expressed his excitement about the availability of two safe and effective malaria vaccines, stating, “Demand for the RTS,S vaccine far exceeds supply, so this second vaccine is a vital additional tool to protect more children faster, and to bring us closer to our vision of a malaria-free future.”
Dr Matshidiso Moeti, the WHO Regional Director for Africa, emphasized the importance of this recommendation for the continent, stating, “This second vaccine holds real potential to close the huge demand-and-supply gap. Delivered to scale and rolled out widely, the two vaccines can help bolster malaria prevention and control efforts and save hundreds of thousands of young lives in Africa from this deadly disease.”
Key Features of the R21 Malaria Vaccine
The updated WHO recommendation for the R21 malaria vaccine is based on evidence from an ongoing clinical trial and other studies. These studies have shown the following key features of the vaccine:
-
High efficacy during the high transmission season: In areas with highly seasonal malaria transmission, where the disease is limited to 4 or 5 months per year, the R21 vaccine has been shown to reduce symptomatic cases of malaria by 75% during the 12 months following a 3-dose series. A fourth dose given a year after the third maintained efficacy. This high efficacy is similar to the seasonal efficacy demonstrated by the RTS,S vaccine.
-
Good efficacy in an age-based schedule: The R21 vaccine has shown good efficacy (66%) during the 12 months following the first 3 doses. A fourth dose given a year after the third maintained efficacy.
-
High impact in various transmission settings: Mathematical modeling estimates indicate that the R21 vaccine is expected to have a high public health impact in a wide range of malaria transmission settings, including low transmission settings.
-
Cost effectiveness: The cost of the R21 vaccine, estimated at US$ 2 – US$ 4 per dose, is comparable to other recommended malaria interventions and childhood vaccines, making it a cost-effective solution.
-
Similarity to RTS,S vaccine: There is no evidence to date showing that either the R21 or RTS,S vaccine performs better than the other. The choice of which vaccine to use in a country should be based on programmatic characteristics, vaccine supply, and affordability.
-
Safety: The R21 vaccine has been shown to be safe in clinical trials, and safety monitoring will continue as with any new vaccine.
The next steps for the R21/Matrix-M vaccine include completing the ongoing WHO prequalification process, which would enable international procurement of the vaccine for broader rollout. At least 28 countries in Africa plan to introduce a WHO-recommended malaria vaccine as part of their national immunization programs, and Gavi, the Vaccine Alliance, has approved providing technical and financial support for the rollout of malaria vaccines in 18 countries. The RTS,S vaccine is scheduled to be rolled out in some African countries in early 2024, while the R21 malaria vaccine is expected to become available to countries in mid-2024.
Recommendations on Dengue Vaccine
Dengue is a significant public health burden in endemic countries and is expected to increase in incidence and geographic expansion due to climate change and urbanization. The WHO has issued recommendations for a live-attenuated quadrivalent dengue vaccine developed by Takeda (TAK-003).
The vaccine has demonstrated efficacy against all four serotypes of the dengue virus in baseline seropositive children (4-16 years) in endemic countries, and it has shown efficacy against serotypes 1 and 2 in baseline seronegative children. Based on this evidence, SAGE recommends considering the introduction of the vaccine in settings with a high dengue disease burden and high transmission intensity to maximize its public health impact and minimize potential risks in seronegative individuals.
SAGE recommends introducing the vaccine to children aged 6 to 16 years, preferably 1-2 years prior to the age-specific peak incidence of dengue-related hospitalizations. The vaccine should be administered in a 2-dose schedule with a 3-month interval between doses. In addition to vaccine introduction, SAGE emphasizes the importance of a well-designed communication strategy and community engagement.
Recommendations on Meningitis Vaccine
SAGE has recommended that all countries in the African meningitis belt introduce a novel pentavalent meningococcal conjugate vaccine targeting serogroups A, C, Y, W, and X (Men5CV) into their routine immunization programs. The vaccine should be administered in a single-dose schedule at 9 to 18 months of age.
In high-risk countries and countries with high-risk districts, a catch-up campaign should also be conducted at the time of the vaccine introduction, targeting all individuals aged 1 to 19 years.
Recommendations on COVID-19 Vaccine
SAGE has reviewed updated data on the epidemiology of COVID-19, including death rates among priority-use groups, vaccine effectiveness against the Omicron variant, and pre-clinical and clinical data on novel monovalent vaccines.
Based on this data, SAGE recommends a simplified single-dose regime for primary immunization with most COVID-19 vaccines. This simplified regime improves acceptance and uptake while providing adequate protection, especially considering that most people have had at least one prior infection.
Monovalent vaccines targeting the Omicron variant have been shown to provide modestly enhanced protection compared to bivalent variant-containing vaccines and monovalent index virus vaccines. However, when monovalent vaccines are not available, any WHO emergency-use listed or prequalified vaccine, whether bivalent or monovalent, can be used as they continue to provide benefits against severe disease in high-risk groups.
IA2030 Progress and Recommendations
Progress against the IA2030 indicators, which aim to improve global immunization coverage and control vaccine-preventable diseases, has been stalled due to the impact of the COVID-19 pandemic. Six of the seven impact goal targets are off-track, with only the target for the introduction of new vaccines remaining on track, thanks to the introduction of new vaccines in low-income countries in 2022.
While there are promising signs of recovery, progress is uneven, particularly in low-income countries and vulnerable populations living in fragile and conflict-affected settings. The low coverage of measles-containing vaccines has increased the risk of large, disruptive outbreaks.
To address these challenges, the WHO has developed a shared action agenda for 2023-2024. This agenda sets out a series of short-term and high-level priorities to align the efforts of countries, regions, global partners, and other stakeholders. The action agenda focuses on six trajectories:
- Catch-up and strengthening of immunization programs
- Promotion of equity in immunization
- Regaining control of measles
- Making the case for investment in immunization
- Accelerating the introduction of WHO-recommended vaccines
- Advancing vaccination in adolescence
These trajectories aim to address the current gaps in immunization coverage and ensure that every individual, regardless of their socioeconomic status or geographical location, has access to life-saving vaccines.
In conclusion, the WHO’s health advice for 2023 includes significant recommendations for malaria prevention in children, dengue vaccination, meningitis vaccination, and COVID-19 vaccination. These recommendations are based on extensive research and aim to improve global health outcomes by preventing and controlling these infectious diseases. Additionally, the WHO highlights the need for accelerated progress in immunization programs and the importance of addressing the challenges posed by the COVID-19 pandemic. By implementing these recommendations and working together, we can strive towards a healthier future for all.