Noninvasive Real‐Time Monitoring of Liver‐Stage Development of Bioluminescent<i>Plasmodium</i>Parasites

Background: The morbidity and mortality associated with malaria are heightened because of the spread of drug-resistant parasites and the lack of an effective vaccine. Plasmodium liver stages are the targets of new chemotherapeutics and vaccines, but there are limited tools available to study this stage in vivo. Methods: To overcome this obstacle, we developed a method with which to study Plasmodium liver stages by means of bioluminescent imaging (BLI) of the rodent malaria parasite Plasmodium yoelii. We created a P. yoelii YM strain (PyLuc) that stably expresses firefly luciferase driven by a constitutive promoter. Results: Using BLI, we performed imaging of the Plasmodium liver stages of mice infected with PyLuc sporozoites and monitored parasite dissemination during blood-stage infection. Because PyLuc luciferase activity is proportional to the number of parasites, BLI can be used to quantify the effect of drugs on liver-stage development. Moreover, using BLI, we demonstrated that immunization with blood-stage parasites confers partial protective immunity against the development of liver stages. Conclusions: BLI is a noninvasive technique that is useful for screening potential drugs and candidate vaccines with which to combat malaria. The prospect of cross-stage protective immunity increases the number of avenues to be explored in the development of an effective vaccine against malaria

Noninvasive Real‐Time Monitoring of Liver‐Stage Development of Bioluminescent<i>Plasmodium</i>Parasites

Background. The morbidity and mortality associated with malaria are heightened because of the spread of drug-resistant parasites and the lack of an effective vaccine. Plasmodium liver stages are the targets of new chemo- therapeutics and vaccines, but there are limited tools available to study this stage in vivo. Methods. To overcome this obstacle, we developed a method with which to study Plasmodium liver stages by means of bioluminescent imaging (BLI) of the rodent malaria parasite Plasmodium yoelii. We created a P. yoelii YM strain (PyLuc) that stably expresses firefly luciferase driven by a constitutive promoter. Results. Using BLI, we performed imaging of the Plasmodium liver stages of mice infected with PyLuc spo- rozoites and monitored parasite dissemination during blood-stage infection. Because PyLuc luciferase activity is proportional to the number of parasites, BLI can be used to quantify the effect of drugs on liver-stage development. Moreover, using BLI, we demonstrated that immunization with blood-stage parasites confers partial protective immunity against the development of liver stages. Conclusions. BLI is a noninvasive technique that is useful for screening potential drugs and candidate vaccines with which to combat malaria. The prospect of cross-stage protective immunity increases the number of avenues to be explored in the development of an effective vaccine against malaria

Noninvasive Real‐Time Monitoring of Liver‐Stage Development of Bioluminescent<i>Plasmodium</i>Parasites

Background. The morbidity and mortality associated with malaria are heightened because of the spread of drug-resistant parasites and the lack of an effective vaccine. Plasmodium liver stages are the targets of new chemo- therapeutics and vaccines, but there are limited tools available to study this stage in vivo. Methods. To overcome this obstacle, we developed a method with which to study Plasmodium liver stages by means of bioluminescent imaging (BLI) of the rodent malaria parasite Plasmodium yoelii. We created a P. yoelii YM strain (PyLuc) that stably expresses firefly luciferase driven by a constitutive promoter. Results. Using BLI, we performed imaging of the Plasmodium liver stages of mice infected with PyLuc spo- rozoites and monitored parasite dissemination during blood-stage infection. Because PyLuc luciferase activity is proportional to the number of parasites, BLI can be used to quantify the effect of drugs on liver-stage development. Moreover, using BLI, we demonstrated that immunization with blood-stage parasites confers partial protective immunity against the development of liver stages. Conclusions. BLI is a noninvasive technique that is useful for screening potential drugs and candidate vaccines with which to combat malaria. The prospect of cross-stage protective immunity increases the number of avenues to be explored in the development of an effective vaccine against malaria

Noninvasive Real‐Time Monitoring of Liver‐Stage Development of Bioluminescent<i>Plasmodium</i>Parasites

Background: The morbidity and mortality associated with malaria are heightened because of the spread of drug-resistant parasites and the lack of an effective vaccine. Plasmodium liver stages are the targets of new chemotherapeutics and vaccines, but there are limited tools available to study this stage in vivo. Methods: To overcome this obstacle, we developed a method with which to study Plasmodium liver stages by means of bioluminescent imaging (BLI) of the rodent malaria parasite Plasmodium yoelii. We created a P. yoelii YM strain (PyLuc) that stably expresses firefly luciferase driven by a constitutive promoter. Results: Using BLI, we performed imaging of the Plasmodium liver stages of mice infected with PyLuc sporozoites and monitored parasite dissemination during blood-stage infection. Because PyLuc luciferase activity is proportional to the number of parasites, BLI can be used to quantify the effect of drugs on liver-stage development. Moreover, using BLI, we demonstrated that immunization with blood-stage parasites confers partial protective immunity against the development of liver stages. Conclusions: BLI is a noninvasive technique that is useful for screening potential drugs and candidate vaccines with which to combat malaria. The prospect of cross-stage protective immunity increases the number of avenues to be explored in the development of an effective vaccine against malaria

Herpes zoster recurrence, and safety and immunogenicity of the recombinant zoster vaccine in adults aged ≥50 years with a history of herpes zoster: A phase 3, randomized controlled trial

Objectives: To assess HZ recurrence (primary objective), safety and immunogenicity of the recombinant zoster vaccine (RZV) in adults with prior HZ. Methods: This phase 3, observer-blind, multi-country study (NCT04091451) enrolled participants >= 50 years with one resolved HZ episode > 6 months prior, randomized 1:1 to receive two RZV or placebo doses 2 months apart. Recurrent HZ cases were confirmed by an algorithm comprising varicella-zoster virus-PCR and HZ adjudication determination. The non-inferiority objective for HZ recurrence over >= 26 months was met if the upper limit of the 95% confidence interval (CI) of the HZ recurrence incidence rate ratio (IRR) in the RZV vs placebo groups was = 1 dose of RZV (714)/placebo (712), eight HZ recurrence cases were confirmed, all in placebo recipients (IRR RVZ vs placebo: 0.00 [95%CI: 0.00-0.46]; non-inferiority objective met). No safety signals were identified. Two RZV doses elicited robust immune responses in this population. Conclusion: In participants >= 50 years with prior HZ, RZV does not increase HZ recurrence risk. RZV was immunogenic, and safety results were consistent with the vaccine's known safety profile, providing evidence to support RZV use in this population. (c) 2025 GSK. Published by Elsevier Ltd on behalf of The British Infection Association. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Imaging of the spleen in malaria

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