Malaria is a disease caused by bites from infected, female mosquitoes. The disease can be life-threatening. It killed roughly 409,000 people around the world in 2019 alone.

Globally, an estimated 3.4 billion people in 92 countries are considered to be at risk of being infected with malaria and developing symptoms. It may be surprising that most cases occur on the African continent. Malaria is common in the area south of the Sahara Desert (called sub-Saharan Africa) because the disease spreads almost entirely in poor regions with tropical and subtropical climates. The local weather allows for transmission to occur year round. A particular type of mosquito (the anopheles gambiae complex) that is responsible for high, effective rates of transmission resides there. It can reproduce only in moisture-rich environments, which is why a tropical climate is important for malaria's transmission.

Malaria occurs frequently and is quite lethal in parts of Africa because the parasite that causes the infectious disease called Plasmodium falciparum is endemic to the region. This species is the one most likely to cause severe malaria and death.

Limited resources and socioeconomic instability have also made malaria control difficult. Prevention is the main strategy to reduce malaria transmission, which is why financial stability is important in the global fight against malaria. The cost of measures like insecticide-treated bed nets and antimalarial drugs are tremendous across an entire population. These are some of the major reasons why other countries might have high rates of malaria cases but fewer deaths than in Southern Africa.

Symptoms of malaria are varied. The first include fever, headache, and chills, which usually begin 10-15 days after a bite from an infected mosquito. It can be difficult to tell the difference between symptoms caused by malaria and other diseases, as these effects can be caused by a number of illnesses like influenza, respiratory infections, stomach viruses, and other ailments. In severe cases of malaria (which usually occur in children), symptoms can include severe anemia, respiratory distress, cerebral malaria, of multiple organ failure. It is not uncommon to see the rapid progression of malaria symptoms if left medically untreated, which is a primary cause of death in infected people.

Certain groups of people are at higher risk for contracting malaria and developing severe symptoms: children under five years of age, infants, pregnant women, people living with HIV/AIDS, non-immune migrants, mobile populations, and travelers. Children under five are by far the most vulnerable group as they accounted for 274,000 or 67% of all malaria deaths worldwide in 2019.

Children are susceptible to severe malarial infection because they are too young to have developed partial immunity to the illness. Adults who have have lived in malaria-endemic regions for most of their lives develop some protection against infection from years of exposure. Children are too young to have developed this type of immunity in their short lifespans, as their immune systems are still developing so reactions to the illness can be very severe and lead to death.

Without widespread prevention measures like indoor room spraying, insecticide-treated bednets, taking antimalarial medication before an infection, receiving a malaria vaccine, or not having easy and affordable access to healthcare, children have a higher risk of mortality than most adults in regions where malaria is prevalent.

A new vaccine against malaria is currently being tested through a collaboration with Ghanaian, Kenyan, and Malawian Ministries of Health. RTS,S/AS01 (RTS,S) (also called Mosquirix) is one of the first vaccines that has demonstrated the ability to reduce malaria and life-threatening infections in young children. The vaccine is given in four doses and has been shown to prevent roughly 4 in 10 cases of malaria over a four-year period.

If clinical trial data determines that the vaccine is safe, effective, and can be produced and distributed at a low cost with low barriers to access, this vaccine could potentially save tens of thousands of lives a year.

Another vaccine called R21 is a modified form of Mosquirix with a lower cost and higher level of effectiveness and is undergoing a larger clinical trial now. These vaccine options may bring some relief in regions who've been plagued by the disease for thousands of years. With 229 million malaria cases in 2019, any potential new prevention methods are a welcome occurrence in the fight to stop the spread of this disease.