Water & Health
GM malaria vaccine ‘ milestone ’
By James Gallagher
malaria vaccine that uses a weakened form of the
A parasite has passed a “ critical milestone ” in human safety trials , say researchers . Doctors used a genetically modified form of malaria that was unable to cause a full infection in people .
Trials , published in the journal Science Translational Medicine , suggested it was safe and generated a good immune response .
Tropical disease experts described the findings as “ promising ”.
The malaria parasite goes through multiple stages both in mosquitoes and inside the human body . The team at the Centre for Infectious Disease Research , in Seattle , deleted three genes from the parasite so it could not infect liver cells .
The idea is that “ infecting ” people with the weakened parasite will expose the immune system to malaria , but the parasite will not be able to complete its lifecycle to cause disease .
Ten people took part in the safety trials . No-one went on to develop the disease and there were no severe sideeffects to the treatment .
The patients ’ antibodies were then given to mice , which showed greater immunity when they were deliberately infected with malaria .
Dr Sebastian Mikolajczak , one of the researchers , said : “ The clinical study now shows that the vaccine is completely attenuated in humans and also shows that even after only a single administration , it elicits a robust immune response against the malaria parasite .
“ Together these findings are critical milestones for malaria vaccine development .”
There are two similar approaches to “ attenuating ” the malaria parasite - one involves weakening it by exposing it to radiation and the other gives the patient anti-malarial drugs at the same time as infecting them .
But the most advanced malaria vaccine is years ahead .
RTS , S uses some components from the parasite to generate an immune response and the vaccine is now going through large field trials . However , an approach that uses the whole parasite may ultimately prove more effective .
Sir Brian Greenwood , from the London School of Hygiene and Tropical Medicine , told the BBC News website : “ It is encouraging , but this is a first step toward developing a vaccine .
“ It is really promising and the evidence presented here is enough for challenge studies [ in which people are immunized and then infected with malaria to see if it works ].”
However , he cautioned that the latest approach is “ not practical in the field ” as it requires nearly 200 bites by infected mosquitoes .
Ultimately it would have to be just an injection . Dr Robert Seder , from the Vaccine Research Centre at the National Institutes of Health , said : “ This report is a major advance in malaria vaccine development by providing the first evidence that genetically attenuated Plasmodium falciparumparasites are safe and immunogenic in humans . “ Future studies demonstrating protective efficacy will be the next critical milestone for continued development of this promising vaccine approach ”.
Source : BBC News
Water Fluoridation Basics
The mineral fluoride occurs naturally on earth and is released from rocks into the soil , water , and air . All water contains some fluoride . Usually , the fluoride level in water is not enough to prevent tooth decay ; however , some groundwater and natural springs can have naturally high levels of fluoride .
Fluoride has been proven to protect teeth from decay . Bacteria in the mouth produce acid when a person eats sugary foods . This acid eats away minerals from the tooth ’ s surface , making the tooth weaker and increasing the chance of developing cavities . Fluoride helps to rebuild and strengthen the tooth ’ s surface , or enamel . Water fluoridation prevents tooth decay by providing frequent and consistent contact with low levels of fluoride . By keeping the tooth strong and solid , fluoride stops cavities from forming and can even rebuild the tooth ’ s surface .
Community water fluoridation is the process of adjusting the amount of fluoride found in water to achieve optimal
30 Africa Water , Sanitation & Hygiene • September 2018