The first malaria vaccine passed 1 million doses, but it has its drawbacks

Earlier this week, Dr. Kwaku Poku Asante from Ghana received a phone call that was always frightening. It was his son’s school. Her son had a fever. “I don’t know if it’s malaria, but I’m worried,” he says.

Asante’s son is 14 years old, so he is not at risk for children 5 and younger. However, parents in many African countries fear childhood malaria.

This illness defines much of Asante’s professional life as director of the Kintampo Health Research Center. “I’ve seen a lot, a lot, a lot of kids from the hospital,” he says. “Sometimes [they] eating in convulsions. Sometimes they come with severe anemia. Sometimes they vomit. ”

Sometimes these children die. In 2020, the World Health Organization estimated that nearly a quarter of a billion cases of malaria had killed 627,000 children and adults, primarily in Africa. For many years, the best protection has been prevention — bed nets treated with insecticides, anti-malarial pills, closing windows at night, and reducing mosquito habitats.

“With all these interventions, it’s time we’re on the plateau,” says the doctor. Rose Jalangho works for the National Vaccines and Immunizations Program at the Kenyan Ministry of Health. “At that time, we needed new tools to further reduce the burden of malaria.”

The new weapon came last fall when the WHO approved a malaria vaccine – the first to be introduced against the parasitic disease – in Ghana, Kenya and Malawi. And now it has reached this stage – as of April, 1 million children have received at least one dose.

The timing of the vaccine is very important. During the pandemic, there were cases of mosquito-borne diseases and deaths.

“Oh, that has completely changed the game,” says Jalang’o, who coordinates Kenya’s malaria vaccination efforts.

The vaccine has been around for a long time. It took more than 30 years to develop because “malaria parasites are very complex,” says the doctor. Mary Hamel heads the WHO malaria vaccine team. Its nearly 5,000 genes (only about 30 for SARS-CoV-2) have allowed it to escape from our immune system through various adaptations. The vaccine combines an immune stimulant and a protein that “completely covers the outer membrane of the first stage of the malaria parasite, called sporozoite,” explains Hamel.

There are concerns about the effectiveness of the new vaccine and its required schedule. It requires 3 or 4 doses before the age of 2 – a challenge for parents. In addition, the vaccine reduces the number of hospitalizations for severe malaria by only 30%, and there is a large error in this figure. Although children take protective measures at a vulnerable age, with three doses, the effectiveness may be reduced.

But these benefits can be extended. The fourth dose, says Hamel, prolongs protection by 3 1/2 or even 4 years. In addition, vaccination before the malaria outbreak season provides additional protection at critical times.

“Having a malaria vaccine has the potential to reduce malaria-related deaths, so I think it’s a really big deal,” Jalango said. According to him, community members told him that their children were less likely to get malaria. the past.”

“You know, it’s not perfect,” says Dianne Wirth, a geneticist at Harvard TH Chan School of Public Health. “Would I want a vaccine that is 100% effective and easily given in a single dose? Of course. But that’s not true.” Wirth heads an independent malaria advisory group at the WHO, noting: “The vaccine provides some protection. I don’t think it’s justified not to use it. It’s important that it is available to the general public.”

In addition, local health experts say the vaccine is not intended to replace other measures, such as bed nets. This is another layer of protection.

And with other vaccines and prophylactic treatments, Dr. Asante is optimistic. “At this point,” he says, “if there is a vaccine, we can improve it over time.”

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