Background/Objectives: We developed a multistage Plasmodium falciparum vaccine using a heterologous prime-boost immunization strategy. This involved priming with a highly attenuated, replication-competent vaccinia virus strain LC16m8Δ (m8Δ) and boosting with adeno-associated virus type 1 (AAV1). This approach demonstrated 100% efficacy in both protection and transmission-blocking in a murine model. In this study, we compared our LC16m8∆/AAV1 vaccine, which harbors a gene encoding Pfs25-PfCSP fusion protein, to RTS,S/AS01 (RTS,S) in terms of immune responses, protective efficacy, and transmission-blocking activity (TBA) in murine models. Methods: Mice were immunized following prime-boost vaccine regimens m8∆/AAV1 or RTS,S and challenged with transgenic Plasmodium berghei parasites. Immune responses were assessed via ELISA, and TB efficacy was evaluated using direct feeding assays. Results: m8∆/AAV1 provided complete protection (100%) in BALB/c mice and moderate (40%) protection in C57BL/6 mice, similar to RTS,S. Unlike RTS,S’s narrow focus (repeat region), m8∆/AAV1 triggered antibodies for all PfCSP regions (N-terminus, repeat, and C-terminus) with balanced Th1/Th2 ratios. Regarding transmission blockade, serum from m8∆/AAV1-vaccinated BALB/c mice achieved substantial transmission-reducing activity (TRA = 83.02%) and TB activity (TBA = 38.98%)—attributes not observed with RTS,S. Furthermore, m8∆/AAV1 demonstrated durable TB efficacy (94.31% TRA and 63.79% TBA) 100 days post-immunization. Conclusions: These results highlight m8∆/AAV1′s dual action in preventing sporozoite invasion and onward transmission, a significant advantage over RTS,S. Consequently, m8∆/AAV1 represents an alternative and a promising vaccine candidate that can enhance malaria control and elimination strategies.

Background/objectives: We developed a multistage Plasmodium falciparum vaccine using a heterologous prime-boost immunization strategy. This involved priming with a highly attenuated, replication-competent vaccinia virus strain LC16m8Δ (m8Δ) and boosting with adeno-associated virus type 1 (AAV1). This approach demonstrated 100% efficacy in both protection and transmission-blocking in a murine model. In this study, we compared our LC16m8∆/AAV1 vaccine, which harbors a gene encoding Pfs25-PfCSP fusion protein, to RTS,S/AS01 (RTS,S) in terms of immune responses, protective efficacy, and TB activity in murine models. Methods: Mice were immunized following prime-boost vaccine regimens m8∆/AAV1 or RTS,S and challenged with transgenic Plasmodium berghei parasites. Immune responses were assessed via ELISA, and TB efficacy was evaluated using direct feeding assays. Results: m8∆/AAV1 provided complete protection (100%) in BALB/c mice and moderate (40%) protection in C57BL/6 mice, similar to RTS,S. Unlike RTS,S’s narrow focus (repeat region), m8∆/AAV1 triggered antibodies for all PfCSP regions (N-terminus, repeat, and C-terminus) with balanced Th1/Th2 ratios. Regarding transmission blockade, serum from m8∆/AAV1-vaccinated BALB/c mice achieved substantial transmission-reducing activity (TRA = 83.02%) and TB activity (TBA = 38.98%)—attributes not observed with RTS,S. Furthermore, m8∆/AAV1 demonstrated durable TB efficacy (94.31% TRA and 63.79% TBA) 100 days post-immunization. Conclusions: These results highlight m8∆/AAV1's dual action in preventing sporozoite invasion and onward transmission, a significant advantage over RTS,S. Consequently, m8∆/AAV1 represents an alternative and a promising vaccine candidate that can enhance malaria control and elimination strategies.

Recently, several studies using cloned PCR amplicons for sequencing have revealed higher haplotype variation in Giardia intestinalis assemblage B, a variation not detected by conventional methods. This study aimed to estimate the geographical gene flow of G. intestinalis assemblage B using this highly divergent haplotype set. Stool samples were collected from healthy children at two sites (Waitabula and Wainyapu) on an isolated Indonesian island. Partial sequences of glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi), and beta-giardin (bg) gene loci were used as targets for PCR detection. Sequence analysis of the cloned PCR amplicons confirmed the presence of unique haplotypes in each area. For the analysis, we employed not only the Indonesian (Waitabula and Wainyapu) haplotypes acquired in this study but also the Kenyan haplotypes detected in our previous study. Phylogenetic relationships among haplotypes were calculated and plotted using multidimensional scaling (MDS). The plot containing the three loci information suggests the existence of a founder effect between the Waitabula and Wainyapu populations. It also indicates the different evolutionary backgrounds of assemblage B in Kenya and Indonesia. This study demonstrates that employing higher haplotype variations detected using the PCR-cloning method is an effective way to detect geographical gene flow in G. intestinalis assemblage B.

Diseases caused by beetle larvae infestation are known as intestinal canthariasis. Canthariasis from the cigarette beetle, Lasioderma serricorne, , is quite rare; however, with the accumulation of genetic references, such cases of accidental pseudo-parasitism have been increasingly recognized. Here, we describe a case of asymptomatic gastrointestinal passage of L. serricorne in a 4-year-old male. Larval identification was conducted by PCRsequencing targeting cytochrome c oxidase subunit 1 using DNA extracted from the larvae. Due to the difficulty of differential identification of beetles using larval morphology, DNA barcoding is essential.

Zhu N, et al. Clin Exp Vaccine Res. 2026 ;15:e22. https://doi.org/10.7774/cevr.2026.15.e22