Malaria is a serious and fatal disease that affects millions of people every year, particularly in sub-Saharan Africa. According to the World Health Organization (WHO), there were an estimated 241 million cases of malaria worldwide in 2020, resulting in approximately 627,000 deaths[1,2]. Sadly, this disease particularly affects young children under five years of age, who account for two-thirds of all malaria deaths. However, there is good news on the horizon with the development of the R21 malaria vaccine, which brings promising news for the future.
This World Malaria Day let’s know more about the R21 malaria vaccine:
1. First developed by Oxford University
The R21 malaria vaccine was first developed by a team of researchers at Oxford University in the UK. It is indicated for preventing malaria in children from 5-36 months of age, the most vulnerable group at risk of malaria-related deaths[3].
2. Vaccine moves to phase III trial following positive phase II results
The R21 vaccine has undergone clinical trials in Thailand, the UK, and several African countries, in collaboration with the World Health Organization (WHO) and other partners. Currently, the vaccine has completed its phase II trial and is in phase III trial, with 4,800 children being enrolled in Burkina Faso, Kenya, Mali, and Tanzania. Results from these ongoing phase III trials are expected to be reported later this year[3].
3. R21 becomes the first malarial vaccine to exceed the WHO’s 75% efficacy target
The R21 malaria vaccine has demonstrated high efficacy in phase II trials, including amongst children who received a booster dose of R21 at one year following a primary three-dose regimen. The vaccine has been found to be 77% effective at preventing malaria over 12 months. It has met the World Health Organization’s Malaria Vaccine Technology Roadmap goal of a vaccine with at least 75% efficacy[3].
“This new vaccine, called R21, is an improved version of another vaccine, called RTS, S, which the World Health Organization approved last October for wider use in regions with significant malaria transmission. RTS, S was the first-ever vaccine for human parasitic infection. We need to evaluate R21 under more real-world settings. We are optimistic about the new vaccine, but we also recognize that early data is often more promising than when things are actually used in practice.” says Dr. Mekhala Chandra, MD (Consultant, TATA 1mg).
4. The vaccine showed high levels of safety during clinical trials
The safety of the R21 malaria vaccine is being monitored closely during clinical trials. So far, the vaccine has been well-tolerated, with no serious adverse events being reported[3].
5. The R21 malaria vaccine is the need of the hour
According to the latest World Malaria report, there were 247 million cases of malaria in 2021 with an estimated 619,000 malaria deaths globally, with the majority occurring in Sub-Saharan African countries. Children under the age of five accounted for about 80% of all malaria deaths in that region. Meanwhile, India contributes 1.7% of malaria cases and 1.2% of deaths globally. Also, over the last two peak years of the pandemic (2020–2021), COVID-related disruptions spiked 13 million more malaria cases. The R21 malaria vaccine will be hailed as a rare ray of light in a fight over many years[1,2].
6. The vaccine targets the first stage of the parasite’s life cycle
When the Anopheles mosquito carrying the malaria parasite bites a person, it transmits the parasite through the bloodstream, where it shapeshifts through stages of its life cycle. The R21 vaccine targets the ‘sporozoite’, which is the first stage of the malarial parasite’s life cycle when transmitted from mosquitoes to human hosts. It then stimulates the production of antibodies to prevent the parasite from infecting the liver (the first organ to be affected in malaria) and replicating. This prevents the development of the disease and provides immunity against future infections[4,5].
7. Ghana becomes the first country to approve the R21 malaria vaccine
Ghana has become the first country to approve the R21 malaria vaccine, with children under the age of three in line to benefit. The license has been granted by the country’s Food and Drugs Authority (FDA Ghana). Following Ghana, Nigeria has also granted provisional approval to the vaccine[3,6].
8. Serum Institute of India to produce 200 million doses annually
Oxford University has teamed with the Serum Institute of India (SII) to produce up to 200 million doses of the R21 vaccine annually. The SII has also announced the setting up of a vaccine manufacturing unit in Ghana[3].
9. Indian scenario of the R21 vaccine
Currently, there is no information from the drug authorities on the availability of this vaccine in India.
10. Future prospects
If successful, the R21 malaria vaccine has the potential to be a game-changer in the fight against malaria, particularly in sub-Saharan Africa, where the burden of the disease is highest. The vaccine could provide a safe and effective way to prevent malaria in young children, who are at the highest risk of severe disease. In addition to reducing the number of malaria cases and deaths, the R21 vaccine could also provide a more sustainable solution to malaria control. Current interventions such as insecticide-treated bed nets and indoor residual spraying are only effective in the short term, and the development of resistance to insecticides is a growing concern. A malaria vaccine could offer a more long-term and effective solution to curb this life-threatening disease[3].
Overall, the future prospects of the R21 malaria vaccine are promising, and if successful, the vaccine could be a significant development in the fight against malaria.
(The article is written by Monalisa Deka, Senior Health Content Editor, and reviewed by Dr. Swati Mishra, Medical Editor)
Reference
1. World Malaria Report. Available online:
https://www.who.int/india/health-topics/malaria/summary-of-world-malaria-report-2021
2. WHO. Malaria Fact Sheet. Available online:
https://www.who.int/news-room/fact-sheets/detail/malaria
3. Serum Institute of India. Press Release. Available online: https://www.seruminstitute.com/press_release_sii_130423.php
4. Datoo MS, Natama HM, Some A, et al. Efficacy and immunogenicity of R21/Matrix-M vaccine against clinical malaria after 2 years follow-up in children in Burkina Faso: a phase 1/2b randomized controlled trial. 2022. The Lancet. Infectious Disease. 22(12).1728-1736. Available online: https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00442-X/fulltext#:~:text=In%20a%20large%20phase%203,this%20efficacy%20waned%20over%20time.w.t
5. Bertolino P and Bowen DG. Malaria and the liver: immunological hide-and-seek or subversion of immunity from within? Front Microbiol. 2015; 6: 41. Available online: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4332352/#:~:text=The%20liver%20stage%20of%20the,and%20thus%20establishes%20productive%20infection.
6. Oxford University Innovation. Available online:https://innovation.ox.ac.uk/news/university-oxford-malaria-vaccine-receives-regulatory-clearance-use-ghana-nigeria/