The award recognizes Jason McLellan’s work to investigate how viruses infect our cells and to develop new treatments for infectious disease.

Vivax malaria, once thought rare in Duffy-negative Africans, is now reported in various parts of Africa, suggesting alternate invasion mechanisms and parasite adaptability to Duffy-null cells.

Vir genes, a multigene family in Plasmodium vivax that are a part of a larger superfamily of genes called the pir (Plasmodium interspersed repeat) genes have been reported earlier to be potentially involved in cyto-adherence and evasion of splenic clearance. Plasmodium vivax, historically characterized as a "benign" malaria parasite, has been associated with clinical outcomes including hepatic dysfunction, renal failure, and cerebral malaria in India and several global regions. It constitutes an economic burden and presents a public health challenge alongside other Plasmodium species. Here, we present a part of global transcriptomic studies using custom designed microarrays, that compare the transcriptome of the parasite responsible for severe Plasmodium vivax manifestations, specifically hepatic dysfunction and cerebral malaria from India, with an emphasis on the pir genes, some of which are reported to play a role in cyto-adherence. 23 patients with Plasmodium vivax malaria (Uncomplicated=6, Hepatic dysfunction=12 and Cerebral malaria=5) were subjected to microarray hybridization and the data so obtained showed a wide range of pir subfamilies have been differentially expressed. Upregulation has been seen in 24 pir genes in cerebral malaria samples (n=5) and 28 genes in hepatic dysfunction samples (n=12) belonging to different subfamily in at least 50% of the patient samples. Out of the upregulated pir genes in cerebral malaria manifestation, members of vir subfamily E and pvpir H are maximum in number whereas in hepatic dysfunction manifestation, members of vir subfamily E and C comprise a significant proportion.

Plasmodium vivax is the most widely distributed human protozoan in the world. It is a causative agent of malaria, with thrombocytopenia being a frequent complication. This study aimed to evaluate the effect of P. vivax infection on plasma cytokine/chemokine levels and anti-phosphatidylserine (anti-PS) autoantibodies, to explore their potential role in thrombocytopenia during P. vivax malaria in Córdoba, Colombia. We included patients with P. vivax malaria and thrombocytopenia (MT); patients with...

We have established a highly multiplexed rhAmpSeq assay (up to 98 amplicons) to address critical knowledge gaps in our understanding of antimalarial efficacy and transmission dynamics of P. vivax. Our assay can be applied to low-density infections and to NGS...

Pv47 is the Plasmodium vivax ortholog of Pfs47, a protein that allows the Plasmodium falciparum malaria parasite to evade mosquito immunity and adapt to diverse vectors. We analyzed global genetic diversity of Pv47 and compared it with Pfs47, finding that most common Pv47 polymorphisms are non-synonymous and cluster in regions similar to those in Pfs47. Pv47 domain 2 presents an excess of non-synonymous substitutions, suggesting positive selection. The greatest haplotype diversity is found in...

Anopheles darlingi is the principal malaria vector in the Amazon basin, where Plasmodium vivax accounts for the majority of cases. Despite its epidemiological importance, the molecular and microbial determinants of A. darlingi susceptibility to P. vivax remain poorly understood. Here, we investigated vector-parasite-microbiota interactions using experimental infections with field-derived P. vivax gametocytaemic blood, which produced two distinct infection phenotypes: low and high oocyst burdens. Transcriptomic profiling of mosquito midguts across key parasite developmental timepoints revealed that low-infection mosquitoes mounted an early and sustained response characterised by activation of detoxification pathways, redox regulation, aromatic amino acid catabolism, and purine depletion, likely coordinated through neurophysiological cues, which collectively create a metabolically restrictive environment for parasite development. These physiological changes were accompanied by reduced bacterial diversity and enrichment of Enterobacteriales and Pseudomonadales, taxa previously linked to anti-Plasmodium activity. Conversely, high-infection mosquitoes exhibited limited metabolic reprogramming, expansion of Flavobacteriales, and transcriptional signatures consistent with permissive physiological states, potentially associated with reproductive trade-offs. Importantly, low infection outcomes consistently arose from bloodmeals with the lowest gametocyte densities, suggesting that host- and parasite-derived components of the bloodmeal act as early conditioning factors that prime the mosquito midgut for either resistance or susceptibility. These findings reframe A. darlingi vector competence to P. vivax not as a fixed immune trait but as a dynamic outcome of early redox, metabolic, and microbial interactions. They also highlight ecological and physiological targets for transmission-blocking strategies and reinforce the importance of studying vector-parasite interactions in regionally relevant systems.

Publication date: Available online 20 August 2025 Source: International Journal for Parasitology Author(s): Loick P. Kojom Foko, Amit Sharma

The CYP2D6 enzyme plays a critical role in the metabolism of primaquine, the most widely used drug for the radical cure of Plasmodium vivax malaria.

Publication date: Available online 2 July 2025 Source: Acta Tropica Author(s): Michael N. Yakubu, Victor I. Mwangi, Anne C.G. Almeida, Emanuelle Lira, Asenate A.X. Adrião, Gabriel F. dos Santos, Gesiane S. Lima, Lucas S. Machado, Hector H.F. Koolen, Tiago P. Guimarães, Jessica R.S. Alves, Andrea R. Chaves, Boniek G. Vaz, Wuelton M. Monteiro, Fabio T.M. Costa, Marcus V.G. Lacerda, Luiz G. Gardinassi, Gisely C. Melo

Background: Plasmodium vivax poses a major obstacle to malaria elimination because it can lie dormant in the liver for weeks or months before reactivating and causing a relapse of infection. These dormant forms (hypnozoites) cannot be detected using standard diagnostics, but recent P. vivax exposure and by proxy, hypnozoite carriage, can be inferred using antibody-based tests (serological markers). In this study, we examined how genetic variation in P. vivax affects the utility of these antibody markers, and whether redesigned antigens could improve performance. Methods: We analysed global P. vivax genetic data to assess variation in leading serological markers. Based on this, we produced new antigen versions (haplotypes) that better reflect global sequence diversity, compared to the commonly used reference strain (Sal-1). Antibody responses against these new constructs were then tested using samples from well-characterised cohorts in Brazil and Thailand. Antibody levels were assessed in relation to how recently participants had a qPCR-detectable blood-stage P. vivax infection. We compared the ability of the haplotypes and reference constructs to correctly identify individuals infected within the prior 9-months. Findings: Extensive genetic diversity was identified in two P. vivax antigens, DBPII and MSP5. Several antigens had large numbers of circulating haplotypes globally, with the percentage with similar sequence identity to the reference Sal-1 ranging from 0.4% (MSP5) to 99% (S16). Two antigens exhibited strong differences in immunogenicity by region and construct (RBP2a and DBPII). However, for most proteins (5 out of 8), these differences had little impact on the accuracy of identifying recent exposure. In cases where performance was affected (e.g. RBP2a), this could be overcome by adding multiple antigens into the classification model. Interpretation: Even highly diverse antigens can be effective serological exposure markers. Our findings highlight the importance of testing the impact of genetic diversity when designing serological tests and suggest practical strategies, such as using a mix of antigens, to ensure consistent performance across regions.

HEK293T and baby hamster kidney (BHK) cells were cultivated in Dulbecco’s modified Eagle’s medium (DMEM) (Gibco, Life Technologies, New York, USA) enriched with 10% heat-inactivated fetal bovine serum (FBS), non-essential amino acids, penicillin, and streptomycin. Similarly, rabbit kidney (RK13) cells...

Malaria remains a significant public health challenge in Brazil. Plasmodium vivax is the predominant species. Dysregulated immune responses contribute to malaria pathogenesis. In this study, periphera

Plasmodium vivax poses a major challenge for malaria elimination, primarily because of relapse. Primaquine mass drug administration (PQ-MDA) has played a decisive role in eliminating vivax malaria in many temperate countries, but its efficacy in tropical/subtropical areas remains underexplored.

Brazil’s progress toward malaria elimination has stalled and 163,000 new cases (more than 80% caused by Plasmodium vivax) were recorded in the Brazilian Amazon in 2023. We hypothesize that human mobility continues to disperse parasites from hotspots to areas with decreasing endemicity.MethodsWe analyzed 5.5 million malaria case notifications between 2003 and 2023 to describe malaria case mobility and identify sources and sinks of P. vivax in the Brazilian Amazon. We leveraged whole-genome sequence data from 408 P. vivax isolates sampled from across South America to characterize parasite gene flow and infer likely regional routes of parasite dispersal.ResultsWe found that nearly one-third of the P. vivax infections diagnosed in residents in the Brazilian Amazon over 21 years were acquired outside the locality or municipality of residence, but only 1.7% were imported from other countries in South America, mostly from the Guiana Shield. We show that large cities with residual malaria transmission – such as Manaus and Porto Velho – are receptive parasite sinks surrounded by high-risk source rural localities. Although the genetic relatedness of parasites tended to decrease with geographic distance, parasites from sites more than 1,000 km apart often remained genetically connected.ConclusionsUnderstanding parasite source-sink dynamics on different geographic scales is crucial to target high-risk mobile populations and source localities along with receptive sinks within low-transmission municipalities, with the goal of eliminating malaria transmission and preventing its reintroduction into malaria-free areas across the Amazon.

CONCLUSIONS: Understanding parasite source-sink dynamics on different geographic scales is crucial to target high-risk mobile populations and source localities along with receptive sinks within low-transmission municipalities, with the goal of eliminating malaria transmission and preventing its reintroduction into malaria-free areas across the Amazon.

Researchers have uncovered new evidence that challenges long-standing beliefs about asymptomatic malaria infections. The study, led by Monash University's Professor Diana Hansen and published in Molecular Systems Biology, focused on Plasmodium vivax, the most widespread malaria parasite and a major obstacle to global elimination efforts.

Brazil’s progress toward malaria elimination has stalled and 163,000 new cases (more than 80% caused by Plasmodium vivax) were recorded...