New malaria vaccine may not help Nepal

The endorsement on Wednesday in Geneva by the World Health Organisation (WHO) of the new malaria vaccine Mosquirix has been described as a milestone for Africa, but experts doubt if it will be as useful in the Subcontinent.

WHO described the Mosquirix injection as a groundbreaking discovery and recommended its widespread use among children in sub-Saharan Africa and in other regions with moderate to high Plasmodium falciparum transmission.

Every year, malaria kills 260,000 children under five in Africa. The new vaccine, the first to be backed by the WHO for the mosquito-borne parasitic disease, reduces severe infections by 30%, which translates into 78,000 lives saved annually.

“This is a historic moment. The long-awaited malaria vaccine for children is a breakthrough for science, child health and malaria control,” WHO Director-General Tedros Adhanom Ghebreyesus announced at a press conference. “Using this vaccine on top of existing tools to prevent malaria could save tens of thousands of young lives each year.”

The vaccine called RTS,S (trade name Mosquirix) was proven effective six years ago, and through successful pilot immunisation programs, has reached more than 800,000 children in Ghana, Kenya and Malawi since 2019.

The landmark vaccine however may not be as applicable in Nepal and the Subcontinent because malaria parasite here is different. The new vaccine was developed to fight Plasmodium falciparum, but in Nepal and South Asia the dominant malaria-causing parasite is P. vivax. Only a few candidates for P. vivax currently under trial and rhe progress has been slow.

“The vaccine, its studies and recommendation are all Africa-centric,” explains Buddha Basnyat, as physician at the Patan Academy of Health Sciences. “A malaria vaccine with 30% efficacy against severe infections is being welcomed, and yet Covid vaccines, all of them known to reduce complications and fatalities by 80-90% are still rejected by vaccine deniers.”

The approval of the new vaccine does have a lesson for Nepal and the rest of the world for vaccine acceptance as the Covid-19 pandemic continues to spread and make people sick.

Malaria is one of the oldest diseases known to human and still infects over 200 million people annually – 95% in Africa. The WHO and the United States led the global campaign to eradicate malaria in the 1950s and 60s, and while the effort fell short in many countries with mosquitoes quickly developing resistance to the insecticides, the program was relatively successful in Nepal.

While writing for this paper in 2018, environmental historian Tom Robertson stated: ‘Just as malaria shaped Nepal’s past, its almost complete removal in the 1960s and 1970s has shaped Nepal’s present, launching vast demographic, environmental, and political changes that are still playing out.’

He continued: “The near complete removal of the disease from Nepal meant that there were vast movements of people from the hill ridges to valley floors and to the Tarai, as well as movement north from the plains. There was large-scale deforestation and habitat loss, and tumultuous social and political reconfigurations.”

In the coming decades, malaria control was further aided by mass campaigns to raise awareness about preventives measures such as maintaining hygiene, clearing stagnant waters, and the use of treated mosquito nets and repellants.

However, there is no clear data to estimate the disease burden of malaria in Nepal at present. Despite its decreasing trend, climate change is said to be pushing parasite-carrying mosquitos to higher elevations in the Himalaya.

In 2019, Kathmandu saw its biggest dengue outbreak yet with 80,000 infections in five months with outbreaks also in higher altitudes where mosquito-borne diseases were previously unheard of. There are also seasonal outbreaks of viral encephalitis, which is also spread by mosquito bites.

“Vector insects are moving up the Himalaya as warming increases, and so are the diseases they carry. Climate change is leading to changes in the geographic pattern of diseases,” Meghnath Dhimal of the Nepal Health Research Council told Nepali Times in 2019.

His research has shown that mosquitoes do not just travel to higher altitudes in vehicles, but increasingly complete their life cycles in what used to be colder places. Added Dhimal: “Not just dengue: at any moment you can also have outbreaks of Chikungunya, Japanese encephalitis and Zika in the mountains of Nepal due to global warming.”