New vaccine targets mosquito weak spot, offering hope for malaria fight

A promising strategy in the battle against malaria could offer a major step forward in controlling the mosquito-borne disease that continues to take a devastating toll in sub-Saharan Africa, including Kenya

Recent research suggests that targeting and eliminating malaria-causing capabilities in mosquitoes through innovative vaccine technology could transform how the disease is controlled worldwide.

This strategy, pioneered by researchers at the Johns Hopkins Bloomberg School of Public Health, focuses on disrupting the protein quality-control system known as prefoldin chaperonin in Anopheles mosquitoes.

By interfering with this system, scientists have found they can reduce the mosquito’s ability to host and transmit malaria parasites.

Prof George Dimopoulos, the deputy director of the Johns Hopkins Malaria Research Institute, says this approach could one day be effective across all major malaria-endemic regions of the world.

The prefoldin chaperonin system is remarkably consistent across different species of Anopheles mosquitoes, making this strategy potentially universal in its application.

“We believe this could work in all malaria-endemic regions because the prefoldin system is shared by all major Anopheles mosquito species,” says Dimopoulos.

Furthermore, the findings suggest that a vaccine that induces the production of anti-prefoldin antibodies could be a promising tool for disrupting malaria transmission.

Develop resistance

The vaccine would make it difficult for mosquitoes to develop resistance, a major challenge in many existing malaria-control methods. This could provide a significant breakthrough in controlling the disease on a global scale.

Malaria remains one of the most significant public health threats in Kenya, where approximately one-third of the population is at risk. The disease not only places immense pressure on the healthcare system, but also impedes economic development by reducing productivity and draining resources.

In 2020, Kenya’s national malaria prevalence stood at 6 per cent, a significant drop from 11 per cent in 2010, largely due to successful interventions like insecticide-treated bed nets, indoor spraying, and antimalarial drugs.

However, the fight is far from over. Kenya, along with other African nations, continues to grapple with a persistent malaria burden, with the disease accounting for thousands of deaths annually, especially among children under five years of age.

The new vaccine-based strategy represents a promising addition to the tools already available, but its potential effectiveness must be weighed against the challenges that Kenya faces.

In particular, the country has seen considerable progress in reducing malaria-related deaths. For example, the under-five mortality rate from malaria dropped from 11.5 per cent in 2003 to 4.1 per cent in 2022, according to the US President’s Malaria Initiative  2024 report. However, reductions in international aid and shifting funding priorities threaten these gains.

Malaria control in Kenya has long been supported by international partners, with the US President’s Malaria Initiative (PMI) and USAID playing crucial roles in providing funding for prevention programmes. Yet, in recent months, funding cuts have created a gap in crucial services.

The termination of PMI funding has left a Sh24.9 billion deficit in Kenya’s malaria control budget, endangering key programmes such as the distribution of insecticide-treated nets, access to malaria rapid diagnostic tests, and preventive treatments for pregnant women.

Funding shortfall

A recent report by the Oxford Malaria Atlas Project warns that the freeze in PMI activities could lead to an additional 18 million malaria cases and 107,000 deaths globally.

In Kenya, this funding shortfall could cause disruptions in essential services. For example, eight months’ worth of malaria rapid diagnostic test kits and five months of first-line medicines are currently unavailable, threatening the country’s ability to combat the disease effectively.

“This has the potential to erase much of the progress we’ve made,” says Jane Carlton, Director of the Johns Hopkins Malaria Research Institute. “The effectiveness of control programmes hinges not just on interventions, but also on a consistent and reliable funding base.”

The recent study led by Dimopoulos and his team provides a glimmer of hope for tackling malaria transmission from a new angle. The researchers employed a screening technique that temporarily blocked the activity of specific genes in Anopheles mosquitoes, especially in Anopheles gambiae, the primary malaria-transmitting mosquito in sub-Saharan Africa.

Disrupting specific genes in mosquitoes significantly impaired their ability to transmit malaria, killing up to 60 percent during experiments. In Kenya, this breakthrough, combined with other measures, could reduce malaria transmission. However, challenges remain, including ethical concerns and safety issues regarding genetic modifications and vaccine effectiveness.