Malaria vaccine trial results ‘frustrating’
NEW RESULTS from a phase III clinical trial for a malaria vaccine for African infants have been described as “frustrating” after its efficacy proved lower than expected. The RTS, S/AS01 vaccine (RTS, S) reduced the incidence of clinical malaria by 31 per cent and of severe malaria by 37 per cent, when given to infants aged 6-12 weeks. The results were presented at the International African Vaccinology Conference, taking place in Cape Town, South Africa. The trial, conducted on more than 6,500 babies, has seen a significant drop in efficacy, compared with results published last year on the same vaccine for children aged 5-17 months. The data from the older children showed a 56 per cent drop in cases of clinical malaria, and a 47 per cent drop in cases of severe malaria, when three doses of the RTS,S vaccine were given at one-month intervals. “It is frustrating seeing different levels of protection in different age groups,” said Andrew Witty, CEO of GlaxoSmithKline, which has been developing the vaccine together with the PATH Malaria Vaccine Initiative. “If we had seen… a repeat of last year, we would have seen this in a more enthusiastic light,” Witty said. “However, it is very encouraging that the vaccine works.” The researchers speculated that the lower efficacy could be caused by differing immune responses in children of different age groups or differences in malaria transmission rates across the 11 research centres, based in seven countries in Sub-Saharan Africa, where the trial is being conducted. “We will continue to study the factors affecting efficacy of the vaccine, including the duration of efficacy and the effects of a booster dose,” said Salim Abdulla, chief executive director of the Ifakara Health Institute, Tanzania, who led the new trial. However, the trial did confirm the safety of the vaccine, which has been designed to protect against the malaria parasite Plasmodium falciparum. Although vaccinated infants were more likely to develop a non-malarial fever than the control group, the researchers described it as “very low and not requiring medical assistance”. This is in contrast to the initial trial, which found that some 5-17 month-old children vaccinated with RTS,S developed more serious side effects such as convulsions and meningitis. The trial caused controversy last year when trial results from the first age group were published early, prompting critics to question why interim findings were announced at the 12-month mark. Further efficacy and safety data are expected in 2014, when the effects of the vaccine over 30 months will be published. (SciDev)
Pacific coconut gene bank under threat
THE INTERNATIONAL collection of the South Pacific’s coconut palm species, held at a field gene bank in Papua New Guinea (PNG), is under threat from a disease outbreak close to the gene bank. The warning came at a meeting on the Pacific coconut research and development (R&D) strategy in Samoa last month, convened by the Australian Centre for International Agricultural Research and the Secretariat of the Pacific Community. The deadly disease, Bogia Coconut Syndrome, is threatening the survival of gene banks of region’s most important tree, the coconut, a number of which are endemic. Named after the town of Bogia on the north coast of mainland PNG, the disease appears to be caused by bacteria similar to, but distinct from, the better known Lethal Yellowing disease that attacks palm species. Ironically, PNG was selected as the site for the gene bank in the 1990s because the country was relatively free of coconut pests and diseases. In an attempt to contain the disease, movement of coconuts and coconut palms, both from the gene bank and for commercial reasons, out of the affected region has been banned, with roadblocks in place to help enforce this. But these restrictions are preventing the gene bank from fulfilling one of its key roles: distributing useful varieties in support of R&D efforts. The gene bank holds 3,200 coconut palms, representing 57 different varieties of Cocos nucifera, and is one of five international coconut collections around the world. Duplication will not be easy: some of the varieties are not kept in any other gene banks and will need to be collected again from the field. Roland Bourdeix, coordinator of the International Coconut Genetic Resources Network, is arranging an urgent mission to PNG to assess the situation. “We hope to rescue the collection,” Bourdeix says. “We’ll relocate it if there’s a safe way to move the plants. We are also planning to duplicate [the gene bank] in another country.”The crisis is at least providing an opportunity to rethink the strategy for regional coconut conservation,” he says. “For example, we are exploring a concept called ‘polymotu’ — using small islands as gene banks by planting them with one or two varieties. The isolation keeps the varieties pure.” Richard Markham, research programme manager for the Australian Centre for International Agricultural Research, said: “At present, both the pathogen and its epidemiology are poorly understood.” We are supporting research to try to identify the [Bogia Coconut Syndrome] vector and better understand the host range of this disease. Once we have that information, everyone will be better placed to assess the threat — both to coconuts and livelihoods in general.” (SciDev)
‘Poor science’ in deep-sea mining report
A DEBATE has erupted over the scientific validity of the environmental impact statement (EIS) of the world’s first deep-sea mine, located off the coast of Papua New Guinea (PNG). The furore may push the PNG government to convene a further roundtable meeting for experts, before the mine becomes operational next year. The original impact assessment, which prompted the government to give a green light to the mine in 2009, was “completely unacceptable by scientific standards” and based on “second rate science,” according to a review published by the Deep Sea Mining Campaign pressure group. It says the EIS — which paved the way for a Canadian company Nautilus being granted a 20-year mining lease in 2011 — failed to adequately assess the risk of metals contaminating fisheries and people. The PNG government and Nautilus Minerals Inc., the Toronto-based company set to run the Solwara 1 deep-sea mine, claim to be taking the new review seriously, while Coffey Natural Systems, the consultancy firm responsible for the EIS, maintains its assessment was scientifically valid. Nautilus plans to mine sediments from underwater hydrothermal vents that deposit metals such as copper, gold and silver in heavy concentrations on the region’s sea floor. The Solwara 1 mine will excavate and pump sediment to a floating platform, where the ore will be extracted and the waste rock returned to the sea floor via pipes. The 2008 assessment or EIS stated that the project would be “socially acceptable, environmentally responsible, technologically achievable and economically viable”. But the review of that EIS, written by John Luick, a physical oceanographer at the South Australian Research and Development Institute (SARDI), finds it contained “serious omissions and flaws”. In particular, these relate to data provided on the speed and direction of currents at different depths, and on the upwelling of material from the seabed. Because of the omissions, it is impossible to assess adequately the potential contamination to humans and fisheries, the review states. Furthermore, the EIS understated the risk of metals entering the water through emissions on the seabed, leakage during the pumping process, or spills on the surface, Luick said. “They didn’t do a proper analysis,” he said. A spokesman for Nautilus said the company was taking the review seriously and would issue a statement soon. Gunther Joku, special projects director for PNG’s Department of Environment and Conservation, said he would like to hold a forum, so that the Deep Sea Mining Campaign, Nautilus and any other interested groups can present their views publicly. This forum would enable scientists to explain what the project is about, and ensure that experts from all interested groups have a space to convene, Joku said. “We [would] also explain what the government does in terms of applying laws to the project,” he added. But Coffey Natural Systems stands by its results, and says the PNG environment department even commissioned a second consultancy firm, Cardno, to peer review the EIS before granting Nautilus its environmental permit. (SciDev)
Yet, findings of that review have not been made public, and the scientific community appears divided on the issue. Chalapan Kaluwin, a professor of environmental science at the University of Papua New Guinea, says the EIS should have provided a solid basis for the PNG government to decide whether to approve this project, and if so, under what conditions. “The findings of this new report suggest these important decisions were made on the basis of junk science,” he said. However, John Wiltshire, associate chair of the University of Hawaii’s ocean and resources engineering department, said he was not concerned by the EIS’s level of analysis. “My sense is that Nautilus has done a reasonable amount of work,” he said. “I don’t think they would have come to a different conclusion if they had done more analysis.” (SciDev)