Opinion – Esper Kallás: Malaria, its ills and a new vaccine

Infectious diseases have shaped human history and malaria has a prominent place among them all.

There are reports of its victims since the Neolithic period, when the development of agriculture was intensified, with the sedentarization of human groups and the appearance of the first settlements.

Malaria marked great civilizations and is considered one of the main causes for the fall of the Roman Empire. Coincidence or not, the name derives from Italian and means “bad air” (malariafrom medieval Italian), as they believed that the disease emanated from the putrid air of the swamps, which transmitted the disease to people.

It is estimated that, in the 20th century alone, it caused the death of 150 to 300 million people. The main victims are children, from countries south of the African Sahara. And all this, despite the existence of preventive measures, prophylactic drugs and effective treatment. In 2020 alone, there were 241 million cases and 627,000 deaths.

Despite the appeal of countries that suffer from the disease, as well as non-governmental organizations, access to coping measures and investment in research for new solutions remain limited. These parameters define malaria as a “neglected disease.” If it still occurred in developed countries, the search for solutions would most likely be much faster.

Anopheles, the main transmitting mosquitoes of plasmodium, likes hot weather. With a tropical climate, Brazil is a country where there are also cases. However, the local profile of the disease is different from that found in other African countries. The main reason is that here predominates a less aggressive type of plasmodium vivaxwhile the one caused by Plasmodium falciparum leads to the most severe form of presentation.

Even so, there have been several attempts to control the disease in our country. One of the most notorious was the decision to use chloroquine “in mass”. The medication, which made a comeback during the Covid-19 pandemic, was used in the 1950s, as it had an effect against all types of malaria. Having been mixed with table salt, it had an effect but ended up generating another consequence: the Plasmodium falciparum became resistant to chloroquine, leading to a change in treatment guidelines.

The solution eagerly awaited by all is an effective vaccine. And there, the contribution includes strong ties with Brazil.

Ruth Sonntag Nussenzweig dedicated her life to studying malaria. Graduated in medicine at USP, she went with her husband Victor to the USA, unmotivated by the hostile Brazilian moment to researchers, after 1964. Demonstrating its viability in animal models, she developed fundamental tools for the production of a vaccine, tested in several formulations, together with other Brazilian researchers.

In 2021, results from the vaccine, dubbed Mosquirix, were published. It became recommended by the WHO in October, after being shown to be able to reduce cases of severe malaria by 30%, when used in combination with preventive medicines.

Although this protection falls short of what one would like, a phenomenal barrier has been crossed, showing that a vaccine is possible. Such a discovery could put Ruth as a strong candidate for the Nobel Prize in Physiology and Medicine. She died in April 2018.

Combined with the use of repellents, insecticides, protective screens, mosquito control and proper treatment, we hope that this vaccine, and those that may come, can finally control malaria and save millions of lives.