Navigation Links
Investigational malaria vaccine found safe and protective
Date:8/8/2013

An investigational malaria vaccine has been found to be safe, to generate an immune system response, and to offer protection against malaria infection in healthy adults, according to the results of an early-stage clinical trial published Aug. 8 in the journal Science.

The vaccine, known as PfSPZ Vaccine, was developed by scientists at Sanaria Inc., of Rockville, Md. The clinical evaluation was conducted by researchers at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and their collaborators at the Walter Reed Army Institute of Research and the Naval Medical Research Center, both in Silver Spring, Md.

Malaria is transmitted to humans by the bite of an infected mosquito. After the bite occurs, infectious malaria parasites in the immature, sporozoite stage of their life cycle first travel to the liver, where they multiply, and then spread through the bloodstream, at which time symptoms develop.

The PfSPZ Vaccine is composed of live but weakened sporozoites of the species Plasmodium falciparum, the most deadly of the malaria-causing parasites.

"The global burden of malaria is extraordinary and unacceptable," said NIAID Director Anthony S. Fauci, M.D. "Scientists and health care providers have made significant gains in characterizing, treating and preventing malaria; however, a vaccine has remained an elusive goal. We are encouraged by this important step forward."

The Phase I trial, which took place at the NIH Clinical Center in Bethesda, received informed consent from and enrolled 57 healthy adult volunteers ages 18 to 45 years who never had malaria. Of these, 40 participants received the vaccine and 17 did not. To evaluate the vaccine's safety, vaccinees were split into groups receiving two to six intravenous doses of PfSPZ Vaccine at increasing dosages. After vaccination, participants were monitored closely for seven days. No severe adverse effects associated with the vaccine occurred, and no malaria infections related to vaccination were observed.

Based on blood measurements, researchers found that participants who received a higher total dosage of PfSPZ Vaccine generated more antibodies against malaria and more T cellsa type of immune system cellspecific to the vaccine.

To evaluate whether and how well the PfSPZ Vaccine prevented malaria infection, each participantthe vaccinees as well as the control group that did not receive vaccinewas exposed to bites by five mosquitoes carrying the P. falciparum strain from which the PfSPZ Vaccine was derived. This controlled human malaria infection procedurea standard process in malaria vaccine trialstook place three weeks after participants received their final vaccination. Participants were monitored as outpatients for seven days and then admitted to the NIH Clinical Center, where they stayed until they were diagnosed with malaria, treated with anti-malarial drugs and cured of infection, or shown to be free of infection.

The researchers found that the higher dosages of PfSPZ Vaccine were associated with protection against malaria infection. Only three of the 15 participants who received higher dosages of the vaccine became infected, compared to 16 of 17 participants in the lower dosage group who became infected. Among the 12 participants who received no vaccine, 11 participants became infected after mosquito challenge.

"In this trial, we showed in principle that sporozoites can be developed into a malaria vaccine that confers high levels of protection and is made using the good manufacturing practices that are required for vaccine licensure ," said Robert A. Seder, M.D., chief of the Cellular Immunology Section of the NIAID Vaccine Research Center and principal investigator of the trial.

An important challenge in the continued development of PfSPZ Vaccine is that the vaccine currently is administered intravenouslya rare delivery route for vaccines. Previous studies at lower doses have shown that the more common intradermal (into the skin) and subcutaneous (under the skin) routes did not yield as strong an immune response as the intravenous route.

"Despite this challenge, these trial results are a promising first step in generating high-level protection against malaria, and they allow for future studies to optimize the dose, schedule and delivery route of the candidate vaccine," said Dr. Seder.

A number of follow-up studies are planned, including research to evaluate the vaccine's different dose schedules, possible protection against other Plasmodium strains and the durability of protection. The researchers may also evaluate whether higher doses administered subcutaneously or intradermally provide the same level of protection as that found in this study.


'/>"/>

Contact: Nalini Padmanabhan
padmanabhannm@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases
Source:Eurekalert

Related medicine news :

1. Investigational agent targets gene signaling pathways to improve response for patients with CLL
2. Method patent issued for investigational new class of pain medication
3. Detecting malaria early to save lives: New optical technique promises rapid and accurate diagnosis
4. New process would make anti-malarial drug less costly
5. UCI researchers create mosquitoes incapable of transmitting malaria
6. The math of malaria
7. Novel anti-malarial drug target identified
8. New research reveals extent of poor-quality antimalarial medicines in South American countries
9. BioMed Central presents Challenges in Malaria Research: Progress Towards Elimination
10. Novel technique demonstrates interactions between malaria parasite and HIV
11. Meddling with male malaria mosquito mating plug to control an epidemic
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/24/2017)... ... March 24, 2017 , ... ... countries to hospitals in the United States, it’s a threat that is constantly ... obstacles facing infection prevention and offers strategies for the healthcare community to help ...
(Date:3/24/2017)... ... ... According to a new study by NCPA Senior Fellow John R. Graham, "the ... has directed the CBO to follow. The CBO itself previously recognized Obamacare would kill ... a reduction in employer-based coverage due to the GOP reform, which is not plausible. ...
(Date:3/24/2017)... ... March 24, 2017 , ... ... and related services to families and business owners across eastern Michigan, is connecting ... regional families struggling with financial difficulties. , The Oxford/Orion FISH Food Pantry works ...
(Date:3/24/2017)... ... March 24, 2017 , ... As the standards ... a communications platform that positions them as the go-to thought leader in all ... online publication as an always-on, always-fresh news, views and advocacy engine, called ONS ...
(Date:3/24/2017)... ... March 24, 2017 , ... The law firm of ... is pleased to announce Westchester resident Lauren C. Enea has joined the firm as ... firm, will concentrate her practice in elder law, Medicaid planning and applications, and Wills, ...
Breaking Medicine News(10 mins):
(Date:3/24/2017)... Research and Markets has announced the addition of the "Global ... ... very strong with a total of 97 drug candidates. Pharma giant such ... involved in the development of the IPF therapeutics. The IPF pipeline comprised ... 15 are in Phase II stage, 12 are in Phase I stage, ...
(Date:3/24/2017)... India , March 24, 2017 ... of the industry including definitions, classifications, applications and industry ... the international market including development history, competitive landscape analysis, ... ... Ampoules industry spread across 105 pages providing 10 company ...
(Date:3/24/2017)... , March 24, 2017  GenomeDx Biosciences today ... Information Database) and Decipher® Prostate Cancer Classifier tests will ... Association of Urology (EAU) Congress held March 24 to ... The Annual EAU Congress is Europe,s ... comprehensive research in the urological field. The ...
Breaking Medicine Technology: