After close to 30 years of research, GlaxoSmithKline (GSK) has finally filed a regulatory application with the European Medicines Agency for the malaria vaccine RTS,S/AS01.

U.S. Centers for Disease Control and Prevention's Mary Hamel and colleagues carried out a clinical trial of the vaccine RTS,S/AS01 on over 15,000 babies between the ages of six weeks and 17 months. Their findings show that nearly half of the participants were protected for 18 months from malaria after being given the three-dose series of the vaccine. A less than 50 percent success rate doesn't sound impressive but when the opponent is a disease that kills over 600,000 people a year, mostly children, these results are more than good enough.

The study was published in PLOS Medicine and showed that for every 1,000 children that were vaccinated with RTS,S/AS01, an average of 829 cases translated to averted instances of malaria. And though the vaccine protected participants for 18 months after administration, it must be noted that its effectiveness decreases over time. To address this issue, researchers are looking into developing booster shots to make efficacy last longer.

If approved, the RTS,S/AS01 will be the first vaccine to be used on large scale against parasites, which are harder to beat compared to bacteria or viruses. The vaccine works by destroying parasites in the body in the early stages, preventing them from multiplying in the liver and infecting red blood cells.

"This is a key moment in GSK's 30-year journey to develop RTS,S and brings us a step closer to making available the world's first vaccine that can help protect children in Africa from malaria," said GSK's Malaria Vaccine Franchise head, Dr. Sophie Biernaux.

But though a reason to celebrate, Dr. Chris Plowe from the University of Maryland School of Medicine says the vaccine is not a silver bullet. Nirbhay Kumar, a vaccine expert from Tulane University, also warns against raising hopes, adding that expectations must be managed.

Brown University's Dr. Jonathan Kurtis has another concern though: cost. Vaccines are not cheap and massive costs will be incurred given the scale at which RTS,S/AS01 is hoped to be used. GSK has not said how much the vaccine would cost but the company has pledged to cover manufacturing costs plus 5 percent, which it will re-invest in further vaccine research.

GSK is developing the vaccine RTS,S/AS01 with the Path Malaria Vaccine Initiative, a non-profit organization, and funding support from the Bill & Melinda Gates Foundation.

ⓒ 2021 All rights reserved. Do not reproduce without permission.