Home Forums Other Specialities General Topics A Vaccine for Malaria

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    Malaria is a dreadful disease killing thousands and causing misery to millions across the world. Babies and young children are particularly at risk. A few years ago due to careful planning and stringent control of sewage we had almost eradicated the disease in India (especially South India). With complete breakdown of infrastructure malaria is now rife here and vast areas of the country have been declared as endemic. According to the Times of India an estimated one million fresh cases of the disease – which causes body ache and fever – are reported in India each year. About 95 percent of the country’s population resides in malaria endemic areas.

    According to the World Malaria Report 2011, over 70 percent of the country’s 1.2 billion population faces the risk of malaria infection, with an estimated 310 million people – one-third of the total – facing the “highest risk”.

    Inspite of this dreadful scenario we may soon be able to celebrate conquering the disease thanks to the ongoing research by British drugmaker GlaxoSmithKline. They will seek marketing approval for the world’s first malaria vaccine next year after trial data showed the shot significantly cut cases of the disease in African children.

    The vaccine known as RTS,S was found, after 18 months of follow-up, to have almost halved the number of malaria cases in young children in the trial, and to have reduced by around a quarter the number of malaria cases in infants.

    “Based on these data, GSK now intends to submit, in 2014, a regulatory application to the European Medicines Agency (EMA),” GSK, which has been developing the vaccine for three decades, said in a statement. It added that the United Nations health agency, the Geneva-based World Health Organization (WHO), has indicated it may recommend use of the RTS,S vaccine from as early as 2015 if EMA drugs regulators back its licence application.

    Yet hopes that RTS,S would be the final answer were dampened last year when results from a final-stage trial with 6,537 babies aged six to 12 weeks showed the shot provided only modest protection, reducing episodes of the disease by 30 percent compared to immunisation with a control vaccine.

    The latest readout from the malaria trial, which is Africa’s largest ever clinical trial involving almost 15,500 children in seven countries, were presented at a medical meeting in Durban, South Africa.

    GSK is developing RTS,S with the non-profit PATH Malaria Vaccine Initiative (MVI), with grant funding from the Bill & Melinda Gates Foundation

    Previous data sets released from earlier parts of the trial showed the vaccine’s efficacy was 65 percent in babies analysed six months after vaccination, and only around 50 percent in five to 17 month-olds. And further data released earlier this year found RTS,S’s effectiveness wanes over time, with the shot protecting only 16.8 percent of children over four years. Despite these drawbacks, David Kaslow, vice president of product development at PATH, said RTS,S would serve as a useful additional tool alongside other malaria control measures such as mosquito nets, insecticides and anti-malaria drugs.

    “This trial continues to show that a malaria vaccine could potentially bring an important additional benefit beyond that provided by the tools already in use.”
    If approved, the vaccine is unlikely to be anything other than neutral for GSK’s bottom line. GSK has promised that if RTS,S is given the market go-ahead, it will be priced at cost of manufacture plus a 5 percent margin, and the margin would be reinvested in malaria research.

    Malaria vaccine development – WHO fact sheet:
    The complexity of the malaria parasite makes development of a malaria vaccine a very difficult task. Given this, there is currently no commercially available malaria vaccine, despite many decades of intense research and development effort. Over 20 subunit vaccine constructs are currently being evaluated in clinical trials or are in advanced preclinical development.

    RTS,S/AS01 is the most advanced vaccine candidate against the most deadly form of human malaria, Plasmodium falciparum. A Phase III trial began in May 2009 and has completed enrolment in 2011 with 15,460 children in the following seven countries in sub-Saharan Africa: Burkina Faso, Gabon, Ghana, Kenya, Malawi, Mozambique, and the United Republic of Tanzania. There are two age groups in the trial: 1) children aged 5-17 months at first dose receiving only the RTS,S/AS01 vaccine; and 2) children aged 6-12 weeks at first dose who receive the same malaria vaccine co-administered with pentavalent vaccines in the routine immunization schedule. Both groups receive 3 doses of RTS,S/AS01 vaccine at 1 month intervals.

    According to the current trial schedule, the Phase III trial data required in order for WHO to formulate evidence-based policy recommendations are expected to become available to WHO in 2014-2015. Based on currently available data the vaccine will be evaluated as an addition to, not a replacement for, existing preventive, diagnostic and treatment measures. The need for long-lasting insecticidal nets, rapid diagnostic tests and artemisinin-based combination therapies will continue, if RTS,S/AS01 becomes available and is used.

    Tracking the global malaria vaccine portfolio:
    The WHO Initiative for Vaccine Research (IVR) tracks all clinical and advanced preclinical malaria vaccine projects activity in spreadsheets, updates of which are posted on the IVR web pages. These spreadsheets are known as the WHO Rainbow Tables, and are compiled with help from funders, sponsors and investigators around the world. A review of malaria vaccine clinical projects based on the Rainbow Table was published in the Malaria Journal in January 2012.

    To view the complex life cycle of Malaria Parasite click: http://youtu.be/WoIO-g1hiSo

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