Despite the World Health Organisation‘s efforts to promote treatment and control of malaria worldwide, cases are still on the rise and drug resistance has emerged in many endemic regions. There has been significant effort in developing vaccines to treat malaria however these have had limited and short-lived efficacy.
With World Malaria Day celebrated on April 25, it is appropriate to highlight the work being conducted on malaria at the Centre for Innovation in Infectious Disease and Immunology Research (CIIDIR). This is a partnership between Barwon Health and Deakin University’s Institute for Mental and Physical Health and Clinical Translation (IMPACT).
In their recent study, Research Fellow Dr Myo Naung, a member of Professor Alyssa Barry’s team, developed a new computer-based method to study malaria genomes. This approach will help researchers understand the diversity of malaria surface antigens being tested as vaccine candidates, which is crucial for design of more effective malaria vaccines in the future.
Understanding the challenges and gaps
Plasmodium falciparum causes the deadliest type of human malaria and has been evolving together with humans for tens of thousands of years. Over time, this long relationship has left marks on both human and parasite genomes. These marks can help scientists identify the parasite’s surface proteins that the human immune system targets.
The main challenge is that malaria parasites can avoid the immune system by changing and evolving through gene mutation, which leads to a wide variety of parasite strains in circulation.
Taking into consideration the parasite diversity and how the parasite evades the immune system, will help to develop more effective vaccines. Vaccines targeting only a single strain are likely to work well against certain parasite types but not work well against others. After vaccination, the parasite strains that are different from the strain which the vaccine was developed could become more common which will require several additional new vaccines for successfully prevention of malaria.
Contributing to the global fight against malaria
Dr Naung aimed to address the issue of parasite diversity by including multiple variants currently circulating in the global population, similar to how flu vaccine is updated every year. However, malaria is different from the flu virus because it has many stages in its lifecycle, hundreds of surface proteins that could be used for vaccines, and scientists still do not understand how the diversity of these proteins affects the human immune system. To tackle this, Dr Naung conducted a genetic analysis to create a list of common variants that could be included in future vaccines. This research also helps predict how effective these vaccines might be in different populations.
What motivated you to pursue malaria research?
Dr Naung is a dedicated malaria researcher with strong skills in data analysis, population genetics, and vaccine studies. Dr Naung says, “The goal of my research is to reduce malaria deaths in children from low- and middle-income countries. I am committed to helping eliminate malaria through this work and my collaborations with colleagues in malaria endemic countries”.
Diversity of malaria parasites from a coevolutionary relationship
Dr Naung shared that the most exciting finding of this project is the genetic diversity of malaria parasites resulting from the co-evolutionary relationship between humans and malaria parasites.
This study titled “Global diversity and balancing selection of 23 leading Plasmodium falciparum candidate vaccine antigens” published in PLOS Computation Biology, offers a detailed look at the genetic diversity and immune selection of 23 candidate vaccine targets. It also provides a framework for analysing other antigens, helping to identify new vaccine candidates.
The next step is to test these targets in the lab to find new ways the immune system can fight malaria. These discoveries could lead to future vaccines that protect against multiple strains of malaria.