Nav: Home

RTS,S vaccine could favor the acquisition of natural immunity against malaria

August 13, 2019

The RTS,S malaria vaccine could enhance the production of protective antibodies upon subsequent parasite infection, according to a study led by the Barcelona Institute for Global Health (ISGlobal), an institution supported by "la Caixa". The results, published in BMC Medicine, identify the antigens (or protein fragments) that could be included in future, more effective multivalent vaccines.

Immunity to a pathogen can be acquired by natural exposure to the microorganism or through vaccination. The mechanisms underlying both types of immunity are not always the same, particularly in the case of parasites with complex life cycles, such as Plasmodium falciparum, that causes malaria. Over the last few years, ISGlobal researcher Carlota Dobaño and her team have been investigating the immune response induced by the RTS,S, the most advanced malaria vaccine that will be tested at large scale in sub-Saharan Africa this year.

In this study, the authors investigated how vaccination affects natural immunity to the parasite upon subsequent exposure. "To date, most studies had focused on evaluating vaccine-specific responses but not responses towards other parasite antigens," explains Gemma Moncunill, last author of the study. The RTS,S vaccine contains one single parasitic antigen: a fragment of the CSP protein.

The research team analysed serum samples obtained from 195 children, vaccinated or not, who made part of the phase III RTS,S clinical trial and were followed up during 12 months. 78 were from Kintampo, Ghana, a region with high malaria transmission, and 115 were from Manhiça, Mozambique, where transmission is low to moderate. They studied the levels and type of antibodies recognising a total of 38 P. falciparum antigens, including the CSP protein, before and after vaccination.

They found three patterns of antibody responses to these antigens: those that decrease after vaccination, those that are unchanged, and those that increase. Many antibodies in the first group are considered markers of parasite exposure and were associated with a higher malaria risk. Those in the third group were associated with protection - they reduced by half the risk of developing the disease. These protective antibodies mostly recognised antigens expressed by parasite stages that circulate in the blood ant that infect red blood cells.

"We think that the partial efficacy of the vaccine allows low infection levels upon subsequent parasite exposure which in turn leads to the production of protective antibodies," explains Carlota Dobaño. "This effect would be observed especially in regions with low to moderate transmission levels," she adds. Importantly, these results identify antigens that could be included in future and more effective multivalent vaccines.
-end-
REFERENCE:

Dobaño C, Ubillos I, Jairoce C, et al. RTS,S/AS01E immunization increases antibody responses to vaccine unrelated Plasmodium falciparum antigens associated with protection against clinical malaria in African children: a case-control study. 2019 August 14. BMC Med. doi: 10.1186/s12916-019-1378-6

Barcelona Institute for Global Health (ISGlobal)

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

Risk
Why do we revere risk-takers, even when their actions terrify us? Why are some better at taking risks than others? This hour, TED speakers explore the alluring, dangerous, and calculated sides of risk. Guests include professional rock climber Alex Honnold, economist Mariana Mazzucato, psychology researcher Kashfia Rahman, structural engineer and bridge designer Ian Firth, and risk intelligence expert Dylan Evans.
Now Playing: Science for the People

#540 Specialize? Or Generalize?
Ever been called a "jack of all trades, master of none"? The world loves to elevate specialists, people who drill deep into a single topic. Those people are great. But there's a place for generalists too, argues David Epstein. Jacks of all trades are often more successful than specialists. And he's got science to back it up. We talk with Epstein about his latest book, "Range: Why Generalists Triumph in a Specialized World".
Now Playing: Radiolab

Dolly Parton's America: Neon Moss
Today on Radiolab, we're bringing you the fourth episode of Jad's special series, Dolly Parton's America. In this episode, Jad goes back up the mountain to visit Dolly's actual Tennessee mountain home, where she tells stories about her first trips out of the holler. Back on the mountaintop, standing under the rain by the Little Pigeon River, the trip triggers memories of Jad's first visit to his father's childhood home, and opens the gateway to dizzying stories of music and migration. Support Radiolab today at Radiolab.org/donate.