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:12/8/2016)... ... 08, 2016 , ... Russ DiGilio , founder and ... #QuackGivesBack campaign which supported local breast cancer organizations during National Breast Cancer Awareness ... Back initiative, and we’re very pleased with the participation in every franchisee’s ...
(Date:12/8/2016)... , ... December 08, 2016 , ... CURE Media Group, ... and advocacy groups, has aligned with Upstage Lung Cancer in efforts to combat lung ... announcement, Michael J. Hennessy, Jr said, “CURE Media Group is honored to team up ...
(Date:12/8/2016)... Fla (PRWEB) , ... December 08, 2016 , ... ... smarter modes of access for customers and employees that are both engaging and ... 7 with Service Smart Technology, the software company revealed today its plans to ...
(Date:12/8/2016)... ... 08, 2016 , ... STAT courier is pleased to announce that due to ... they are expanding their presence in Dallas. One of the most exciting parts for ... jobs to the Dallas and Forth Worth market. STAT takes pride in treating their ...
(Date:12/8/2016)... ... December 08, 2016 , ... Vida Health, the ... Series B led by Canvas Ventures . Other investors include Nokia Growth Partners ... mobile platform to serve more consumers who are managing chronic conditions or ...
Breaking Medicine News(10 mins):
(Date:12/9/2016)... 9, 2016 Research and Markets has announced ... report to their offering. ... The global travel vaccines market to grow at a ... covers the present scenario and the growth prospects of the global ... report considers the revenue generated from the sales of various vaccines ...
(Date:12/8/2016)... , Dec. 8, 2016 Australia Ophthalmic Lasers ... report, "Australia Ophthalmic Lasers Market Outlook to 2022", provides ... The report provides value, in millions of US dollars, ... segements - Excimer Lasers, Femtosecond Lasers and YAG Lasers. ... shares data for each of these market segements, and ...
(Date:12/8/2016)... KEY FINDINGS The global medical ... Various reasons for growth of the medical lifting sling ... chronic diseases, high recovery cost of injuries and government ... lifting sling refers to an assistive device that helps ... connect to the lift and hold the patient. It ...
Breaking Medicine Technology: