La malaria purtroppo, nonostante l'impegno dell'Organizzazione mondiale della sanità, continua a colpire. E lo fa proprio in Italia, a Trento, dove è deceduta una bambina di 4 anni. Secondo dati epidemiologici recenti, relativi al 2010-2015, i casi di malaria notificati sono 3.633, di cui 89% con diagnosi confermata. La quasi totalità di casi sono d’importazione, i casi autoctoni riportati sono stati soltanto sette. Tra i cittadini italiani si è riscontrato il 20% dei casi. Continuano anche gli sforzi per raggiungere un vaccino efficace.
World Health Organization. Ghana, Kenya and Malawi to take part in WHO malaria vaccine programme
24 April 2017
The WHO Regional Office for Africa (WHO/AFRO) announced today the names of the three countries participating in the WHO-led pilot programme for the RTS,S/AS01 malaria vaccine. The vaccine was developed to protect young children from infection by Plasmodium falciparum, the most deadly malaria parasite globally.
Steady progress toward a malaria vaccine.
Lyke KE. Curr Opin Infect Dis. 2017 Oct;30(5):463-470. doi: 10.1097/QCO.0000000000000393. PMID:28731898
PURPOSE OF REVIEW. Great progress has been made in reducing malaria morbidity and mortality, yet the parasite continues to cause a startling 200 million infections and 500 000 deaths annually. Malaria vaccine development is pushing new boundaries by steady advancement toward a licensed product.
RECENT FINDINGS. Despite 50 years of research, the complexity of Plasmoidum falciparum confounds all attempts to eradicate the organism. This very complexity has pushed the boundaries of vaccine development to new heights, yet it remains to be seen if an affordable vaccine can provide durable and high-level protection. Novel vaccines such as RTS,S/AS01E are on the edge of licensure, but old techniques have resurged with the ability to deliver vialed, whole organism vaccines. Novel adjuvants, multistage/multiantigen approaches and transmission blocking vaccines all contribute to a multipronged battle plan to conquer malaria.
SUMMARY. Vaccines are the most cost-effective tools to control infectious diseases, yet the complexity of malaria has frustrated all attempts to develop an effective product. This review concentrates on recent advances in malaria vaccine development that lend hope that a vaccine can be produced and malaria eradicated.
Vaccines to Accelerate Malaria Elimination and Eventual Eradication.
Healer J, Cowman AF, Kaslow DC, Birkett AJ.
Cold Spring Harb Perspect Med. 2017 Sep 1;7(9). pii: a025627. doi: 10.1101/cshperspect.a025627. Review. PMID:28490535
Abstract
Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.
The GMZ2 malaria vaccine: from concept to efficacy in humans.
Theisen M, Adu B, Mordmüller B, Singh S.
Expert Rev Vaccines. 2017 Sep;16(9):907-917. doi: 10.1080/14760584.2017.1355246. Epub 2017 Jul 21. PMID:28699823
GMZ2 is a recombinant protein consisting of conserved domains of GLURP and MSP3, two asexual blood-stage antigens of Plasmodium falciparum, and is designed with the aim of mimicking naturally acquired anti-malarial immunity. The rationale for combining these two antigens is based on a series of immune epidemiological studies from geographically diverse malaria endemic regions; functional in vitro studies; and pre-clinical studies in rodents and New World monkeys. GMZ2 adjuvanted with alhydrogel® (alum) was well tolerated and immunogenic in three phase 1 studies. The recently concluded phase 2 trial of GMZ2/alum, involving 1849 participants 12 to 60 month of age in four countries in West, Central and Eastern Africa, showed that GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. Areas covered: PubMed ( www.ncbi.nlm.nih.gov/pubmed ) was searched to review the progress and future prospects for clinical development of GMZ2 sub-unit vaccine. We will focus on discovery, naturally acquired immunity, functional activity of specific antibodies, sequence diversity, production, pre-clinical and clinical studies. Expert commentary: GMZ2 is well tolerated and has some, albeit modest, efficacy in the target population. More immunogenic formulations should be developed.
