Using two experimental anti-malarial vaccines, which work in different ways, can greatly reduce the number of malaria infections in animal studies.
Experimental vaccines, which independently achieve 48% and 68% reductions in malaria cases, can achieve 91% reduction when combined.
Presently, each vaccine is at a different stage of human trials, and there have not been efforts to combine them. However, a team led by Imperial College London have now tested the effectiveness when using the two types of vaccine together.
Reaching a potential 91% reduction in cases would have a huge impact on public health because the vaccines could be effective in areas where malaria is more prevalent.Dr Andrew Blagborough
The study, published today in the journal eLife, used genetically altered mouse parasites that express proteins expressed on the human version of the malaria parasite. The research was funded by the PATH’s Malaria Vaccine Initiative and the Medical Research Council (MRC), including researchers at Imperial’s MRC Centre for Outbreak Analysis and Modelling.
Lead researcher Dr Andrew Blagborough, from the Department of Life Sciences at Imperial, said: “This is the first direct evidence than combining vaccines of different types significantly improves their efficacy in terms of reducing malarial burden.
“Reaching a potential 91% reduction in cases would have a huge impact on public health because the vaccines could be effective in areas where malaria is more prevalent.”
Two types of vaccines
Malaria is caused by a group of parasites that have a complex life cycle, spending time in the mosquito midgut and salivary glands, in the human liver, and circulating in human blood, where they cause the disease.
The team tested two types of vaccines: those that prevent mosquitoes from transferring the parasites, called transmission-blocking vaccines (TBVs), and those that prevent the parasite from infecting the liver, termed pre-erythrocytic vaccines (PEVs).
RTS,S is the world’s first PEV malaria vaccine that has been shown to provide partial protection against malaria in young children by blocking infection of the liver. However, its maximum efficacy is under 50% (i.e. it reduces cases by around 50%).
There are currently several types of transmission-blocking vaccines in early trials, which are thought to reduce the number of parasites in the mosquito salivary glands. Their efficacy typically ranges from around 50-95%.
It has been assumed that combining these vaccines would increase their efficacy, but it has never been tested until now. The team found that when a partially effective PEV was combined with the most effective transmission-blocking vaccine, the efficacy was around 91%.
The team also found that combining any of the two types of vaccines improved efficacy of the mixture more than might be expected from the single efficacy of each vaccine separately.
Working towards elimination
Dr Morven Roberts, Programme Manager for parasites and neglected tropical diseases at the MRC, said: “While these findings are in the preliminary stages, they’re valuable as they shed light on optimising strategies for preventing malaria. Learning that combining vaccines can dramatically boost efficacy in mice provides another potential tactic for controlling this disease. This is timely research as global health officials work towards WHO targets to eliminate malaria by 2030.”
The team will next study how combined vaccines could work in more complex situations. Dr Blagborough said: “In the real world, the vaccine coverage we can achieve– how many people we can give it to – is important, as are the local levels of transmission, and how prevalent malaria currently is in that area.
“We plan to use a combination of rodent experiments and computer modelling to help us estimate effectiveness requirements for future vaccines.”
The efficacy of current lead malaria vaccines is known to reduce over time after vaccines are administered, so the team will also investigate how combined vaccines perform in the long term.
The Latest on: Malaria
via Google News
The Latest on: Malaria
- Trump Was Right! 'Malaria Drug' Can Top Covid Survival Rate by 200% - Scientistson June 10, 2021 at 12:50 pm
A malaria drug which Donald Trump was condemned for hailing as a possible COVID-19 treatment can increase survival rates by up to 200 per cent, scientis ...
- Study offers new insight into one of the mysteries of natural immunity to malariaon June 10, 2021 at 8:00 am
In the first and largest global metabolomic study of African children before and after malaria infection, NYU Abu Dhabi Assistant Professor of Biology Youssef Idaghdour and his colleagues at the ...
- New Insight Into One of the Mysteries of Natural Immunity to Malariaon June 10, 2021 at 8:00 am
Researchers compared metabolic responses to human malaria in children of different populations. In 2019, 409,000 people died of malaria--most were young children in sub-Saharan Africa. The annual ...
- Malaria Diagnostics Market to Record 5.10% CAGR Through 2030on June 10, 2021 at 6:48 am
The Malaria Diagnostics market is estimated to reach USD 661.30 Mn in 2021, at a CAGR of 5.10% during the forecast period. Hence, the need for different types of diagnostic tests plays a vital role in ...
- In Jigawa State, WHO backs malaria researchon June 10, 2021 at 12:14 am
The World Health Organization (WHO) is supporting a recent move by the Jigawa State Government to sponsor research on malaria, a preventable but persistent disease in Nigeria. On a recent weekday, WH ...
- Gurugram: Screening of dengue-malaria cases in border areas startson June 9, 2021 at 9:39 pm
After dengue and malaria cases rose in the national capital, the Gurugram District Health Department has also issued an alert. The department has now started screening to identify dengue and malaria ...
- NYUAD study offers new insight into one of the mysteries of natural immunity to malariaon June 9, 2021 at 9:00 pm
The team studied blood samples from children from two ethnic groups in remote rural areas of Burkina Faso, Gouin and Fulani, to see how they responded to the malaria parasite Plasmodium falciparum.
- FG urges unity in fight against Malariaon June 9, 2021 at 8:21 pm
Stakeholders in the Nigerian health sector have been urged to forge a united action against Malaria with a view to eliminating the disease from the country.
- Malaria is far deadlier in Africa than the coronavirus. Why is the vaccine taking so long?on June 7, 2021 at 3:52 am
We are all frustrated in Africa to see how covid gets so much attention compared to malaria,” said epidemiologist Halidou Tinto, regional director of Burkina Faso’s Institute of Research in Health ...
via Bing News