A phase III clinical trial involving more than 4,800 children aged five to 36 months has shown that the R21/MatrixM malaria vaccine has reduced symptomatic malaria cases by between 68 and 75% during the year following its administration. administration. The vaccine has been developed by researchers at the University of Oxford and will be manufactured by the Serum Institute of India (SII) and constitutes a low-cost immunization that will help reduce deaths from this disease in sub-Saharan Africa.
The researchers immunized more than 4,800 young children in a trial in Burkina Faso, Kenya, Mali and Tanzania and found that the average effectiveness was 78% in the age group of five to 17 months during the first year, a period in which The effectiveness was found to be very similar across all sites and in different transmission environments. So far, the Serum Institute of India has manufactured 25 million doses that will be available in the next three to four months. The results of the study have been published in The Lancet.
No other vaccine has reported an efficacy greater than 55% in the same age group. A booster dose every year maintained good efficacy for the next six to 12 months. The vaccine also decreased infection rates in children measured at 12 and 18 months after vaccination, suggesting a potentially beneficial effect in reducing malaria transmission.
Importantly, there have been no serious adverse effects related to immunization. The R21/Matrix-M vaccine was well tolerated, with pain at the injection site and fever being the most common adverse events. The number of adverse events of special interest and serious adverse events did not differ significantly between the vaccine groups. There were no treatment-related deaths.
A breakthrough in the fight against malaria
Malaria is the leading cause of death among young children in Africa, causing more than 600,000 deaths annually worldwide. Recently, two vaccines achieved and completed prequalification by the World Health Organization (WHO) and initial deployments will begin early this year.
“The continued high efficacy of this new vaccine in field trials is very encouraging and consistent with the high efficacy and excellent durability observed in a smaller four-year Phase IIb trial. These data support an important role for unique high-density nanoparticle visualization of the conserved repeat region of the malaria parasite circumsporozoite protein, a feature in the design of the R21 vaccine, in providing such high vaccine efficacy and, therefore, Therefore, an important new tool. for malaria control,” said Professor Adrian Hill, chief investigator of the phase 3 R21/Matrix-M trial.
Significantly greater immune responses to the R21/Matrix-M vaccine and slightly higher vaccine efficacy were observed in children aged five to 17 months compared to malaria vaccines aged 18 to 36 months, supporting the planned rollout of the vaccine initially starting at five months of age in young African children.
The new malaria vaccine “provides greater protection and, at the same time, will allow more extensive vaccination programs against malaria than we had until now”
The vaccine is licensed to the Serum Institute of India, which is the world’s largest vaccine manufacturer and a long-time partner of the University of Oxford. This is critical because vaccinating people at high risk of contracting malaria will be important in stopping the spread of the disease, as well as protecting those vaccinated. Matrix-M adjuvant is manufactured by Novavax AB and provided to the Serum Institute of India for formulation into the final vaccine pharmaceutical product.
Jaime Jesús Pérez Martín, specialist in Preventive Medicine and Public Health, deputy director general of Public Health of the Region of Murcia and president of the Spanish Association of Vaccinology (AEV), who has not participated in the study, explained in statements to SMC Spain that, “as a novelty”, the new vaccine “provides greater protection and, at the same time, will allow more extensive vaccination programs against malaria than we had until now, since a second vaccine will be available that It has a large number of doses prepared for use. Also as an added advantage we could have an increase in the duration of protection.”
“In addition, the vaccine uses a new adjuvant, Matrix-M, which has not been in use until now but can be configured as a very promising adjuvant for use in numerous vaccines. In our country, this adjuvant has only been used in Novavax COVID vaccines, but unfortunately we have had few available, so our experience with said preparation is limited. We hope that the benefits of this adjuvant can be confirmed in other vaccines.”
In the opinion of Consuelo Giménez Pardo, Professor of the Parasitology Area at the University of Alcalá (UAH) and director of the University Master in Humanitarian Health Action (UAH-Médicos del Mundo), and also according to her statements to the aforementioned media: “The main The challenge facing the malaria vaccine is the integration of vaccination into the health system, as an intervention in the strategy for the control and elimination of malaria. Thus, it should be able to be integrated into the vaccination schedule that is already in operation.”
“But in malaria vaccines, there are no panaceas. It must be taken into account that in subunit vaccines the demonstrated efficacy is reduced and is limited to the range between five and seven months of age, for adults these figures decrease to 34% efficacy, in addition to that, according to the available evidence “It does not seem that the protection lasts over time, so vaccinated children would be exposed to malaria again from a very young age.”
“In general terms, efforts should be aimed at improving capacities, both in human resources and infrastructure, to efficiently monitor and manage resistance to insecticides, as well as to have appropriate new products (insecticides, treatments and vaccines). and accessible, useful in the control of malaria,” concludes the expert.
