The World Health Organization has given the green light to a new, more effective malaria vaccine, the first so far to meet the organization’s efficacy standards.
Malaria, a mosquito-borne disease, killed approximately 619,000 people worldwide in 2021 and global cases surpassed 247 million, up from 245 million the previous year and 96 percent of those cases were recorded in the region. WHO, where the disease is endemic and more than one billion people live.
The global health body now recommends the inexpensive R21/Matrix-M vaccine designed by Oxford University, only the second malaria vaccine endorsed by the WHO and the first to meet the agency’s 75 percent efficacy standard.
The first vaccine to earn WHO recommendation was the RTS vaccine in 2021, and despite what the WHO calls “unprecedented” demand for shots, supplies are extremely limited, with only around 18 million doses allocated. for the next two years.
While this vaccine received support from the WHO, it did not live up to the organization’s efficacy standards. However, it is still used to vaccinate people against malaria.
This week’s endorsement marks a big step forward in WHO’s mission to eradicate malaria in at least 30 countries by 2030, but with the first batch of vaccines not available until mid-2024, the disease will have enough time to put the lives of millions at risk.
The graph shows the incidence of malaria cases, or cases per 1,000 people at risk, over time. The incidence of malaria cases decreased from 82.3 per 1,000 in 2000 to 57.2 in 2019, before increasing by approximately four percent in 2020.
The graph above shows the death rate per 100,000 people at risk of malaria. The death rate halved between 2000 and 2015 and has continued to decline.
Approximately 40 million children live in countries affected by malaria and in 2021, 80 percent of malaria cases detected in the Africa region occurred among children under five years of age, up from 72 percent in 2015.
Children, as well as pregnant women and travelers who do not have basic immunity against the parasite that causes malaria, are at greatest risk of severe infection and death.
The new vaccine was tested in five locations in Burkina Faso, Mali, Kenya and Tanzania, where malaria outbreaks occur seasonally with most cases occurring between September and May.
The new R21 vaccine was shown to reduce symptomatic cases of malaria by 75 percent over 12 months following a three-dose injection series.
Like the 2021 RTS vaccine, the R21 vaccine requires a booster after 12 months to maintain protection.
The R21 shots also show a greater ability to protect people from the disease for a longer period of time than the older vaccine.
With a longer protection period, young children are much less likely to get sick and even less likely to experience symptoms such as fever, chills, headache, nausea, joint pain, and rapid heart rate.
The older RTS vaccine’s effectiveness in preventing disease in children ages five to 17 started at 74 percent, but a year later the protective effect had plummeted to 28 percent. In babies six weeks to three months, it fell to 11 percent a year later.
With the new vaccine, there was still 66 percent effectiveness in preventing malaria after one year, and giving a fourth dose of the R21 vaccine a year after the third prevented waning immunity.
The new vaccine was also shown to be safe in clinical trials.
Dr Tedros Adhanom Ghebreyesus, Director-General of WHO, said: “As a malaria researcher, I used to dream of the day when we would have a safe and effective vaccine against malaria. Now we have two.
“Demand for the RTS vaccine (approved in 2021) far outstrips supply, making this second vaccine a vital additional tool to protect more children more quickly and move us closer to our vision of a malaria-free future.”
Malaria infection occurs when a female Anopheles mosquito carrying the Plasmodium parasite bites an unsuspecting victim, transmitting the parasite, which is then transported to the liver, where it can remain inactive for up to a year.
When the parasite matures, it leaves the liver and poisons the bloodstream. Taking medication at the beginning of the infection to kill the parasite solves the problem about 93 percent of the time. But if left untreated, the condition is almost always fatal.
The female Anopheles mosquito becomes infected with the parasite that causes malaria. When it bites a human, that parasite matures in the body until it manifests symptoms that include fever, joint pain and, in most cases where it is not treated, death.
The WHO Africa region accounted for about 95 percent of malaria cases and 96 percent of deaths globally between 2019 and 2020.
Cases in the US occur in sporadic clusters, with approximately 2,000 reported in the country each year, largely related to international travel to destinations where malaria is common.
This year, there have been seven cases of malaria in Florida, one in Texas and one in Maryland.
The burden is heaviest in Africa and tropical regions of Asia, where the climate fuels a thriving population of anopheles mosquitoes and demand for effective, affordable injections has long lagged behind.
The Serum Institute of India (SII), one of the largest vaccine manufacturers in the world, has assured that it will be able to produce 100 million doses per year. That rate will double in the next two years.
And at a price of between $2 and $4 per injection, “the cost-effectiveness of the R21 vaccine would be comparable to that of other recommended malaria interventions and other childhood vaccines,” according to the WHO.
The average cost of RTS shooting is about $5 per unit.
Dr Matshidiso Moeti, WHO regional director for Africa, said: “This second vaccine has real potential to close the huge gap between supply and demand. If deployed on a large scale and widely distributed, the two vaccines can help strengthen malaria prevention and control efforts and save hundreds of thousands of young lives in Africa from this deadly disease.’