TWO
experimental DNA vaccines to prevent Ebola virus and the closely
related Marburg virus are safe, and generated a similar immune response
in healthy Ugandan adults as reported in healthy US adults earlier this
year.
The findings, from the first trial of filovirus vaccines in Africa, are published in The Lancet.
"This is the first study to show comparable safety and immune response of an experimental Ebola vaccine in an African population," says lead author Dr Julie Ledgerwood from the National Institutes of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, USA.
"This is particularly encouraging because those at greatest risk of Ebola live primarily in Africa, and diminished vaccine protection in African populations has been seen for other diseases."
Scientists from the NIAID developed the DNA vaccines that code for Ebola virus proteins from the Zaire and Sudan strains and the Marburg virus protein.
The vaccines contain the construction plans for the proteins on the outer surface of the virus. Immune responses against these proteins have shown to be highly protective in non-human primate models.
In this phase 1 trial, the Makerere University Walter Reed Program enrolled 108 healthy adults aged between 18 and 50 from Kampala, Uganda between November, 2009 and April, 2010.
Each volunteer was randomly assigned to receive an intramuscular injection of either the Ebola vaccine (30 volunteers), Marburg vaccine (30), both vaccines (30), or placebo (18) at the start of the study, and again 4 weeks and 8 weeks later.
The vaccines given separately and together were safe and stimulated an immune response in the form of neutralising antibodies and T-cells against the virus proteins. Four weeks after the third injection, just over half of the volunteers (57 per cent; 17 of 30) had an antibody response to the Ebola Zaire protein as did 14 of 30 participants who received both the Ebola and Marburg vaccines. However, the antibodies were not long-lasting and returned to undetectable levels within 11 months of vaccination.
Both DNA vaccines were well tolerated in Ugandan adults with similar numbers of local and systemic reactions reported in all groups. Only one serious adverse event (neutropenia; low white blood cell count) was reported in a Marburg vaccine only recipient, but was not thought to be vaccine related.
According to Dr Ledgerwood, "These findings have already formed the basis of a more potent vaccine, delivered using a harmless chimpanzee cold virus, which is undergoing trials in the USA, UK, Mali, and Uganda in response to the ongoing Ebola virus outbreak."
Writing in a linked Comment, Dr Saranya Sridhar from the Jenner Institute at the University of Oxford in the UK says, "[This] study deserves to be the focal point around which the broader question of vaccine development, particularly for Africa, must be addressed. With the uncharitable benefit of hindsight in view of the evolving 2014 Ebola outbreak, we must ask ourselves whether a filovirus vaccine should have been in more advanced clinical development.
The international response to the present Ebola outbreak is an exemplar of the speed and purpose with which clinical vaccine development can progress and has set the benchmark against which future vaccine development must be judged. This study is the first step on the aspirational road towards the deployment of filovirus vaccines in Africa and must serve to shake the metaphorical cobwebs that can stall our advance towards this destination."
Meanwhile, although Nigeria has been declared Ebola free by the World Health Organization (WHO), a recent study conducted by the Urban Action Group of the department of Mass Communication, University of Lagos has urged the Nigerian media to step up its interpretative and investigative reportage on disease outbreak, to serve as reminders and a tool for effective prevention and control of the virus in the country.
The study also revealed that the frequency and prominence of the reports by the media played a great role in curbing the spread of the virus in Nigeria.
The group, which gathered and analysed data on the reportage of the outbreak in four national newspapers, isolated a total of 719 published reports within the six-month period under study.The analysisalso revealed that an average of four news items were published per day.
According to the research, the national newspapers in Nigeria have thus fulfilled their social responsibility functions of informing the public about the outbreak of EVD and revealing precautionary measuresto curtail the spread.
However, in the area of interpretation, the study revealed that newspapers have not done so much, because only 26 per cent of reportagewas devoted to the interpretation and analysis of the disease. This is significantly low for a globally noted disease with a high mortality rate.
Founded on two social science theories of Agenda Setting and Social Responsibility, the research understudied the national newspapers in Nigeria and evaluated their ability to facilitate effective control and management of the virus in terms of reportage and analysis.
Besides, only 11 per cent of the newspaper reportage was on the front and back pages. This implies that Nigerian newspapers did not attach much prominence to the coverage of the EVD, probably because of other news items contending for attention, such as insecurity and politics.
The study also pointed out that prior to the outbreak of EVD in Nigeria, only 0.1 per cent was devoted to the reportage of the disease.
The implication, the study reasoned, might be responsible for the haphazard approach the government and entire populace reacted to it.
The study stated: "It also reflects the lack of proactiveness by Nigerian newspapers because EVD was already prevalent in West African countries close to Nigerian borders."
Also identified was another low reportage of 2 per cent on EVD in the month of July when the index case was recorded. Meanwhile, in the month of August after the federal government addressed a press conference on the outbreak, a large space was devoted to the coverage of the disease with 50 per cent of the total news coverage in the months of study. It however began to drop to 30 per cent in the following month of September after the index case had died.
The study also indicated that "by October, prior to the World Health Organization declaring Nigeria Ebola-free, news reportage dropped to 17.9 per cent, which should not have been so, because Nigeria was still at a critical point since the vaccine/cure for the virus had not been found. Our land borders also remained porous, making the country still susceptible to a re-emergence of the EVD."
Based on the findings, the study recommended that Nigerian Newspapers should step up their role in interpretative and Investigative reportage on disease outbreaks.
Other issues highlighted in the study include the need for proper training of journalists, with continuous capacity building on social development issues; communities should been couraged to establish local print media with up-to-date functional libraries for information access and dissemination; Government should also take keen interest in health management by providing appropriate policies that can ensure easy access to medical aid at subsidized rate.
The findings, from the first trial of filovirus vaccines in Africa, are published in The Lancet.
"This is the first study to show comparable safety and immune response of an experimental Ebola vaccine in an African population," says lead author Dr Julie Ledgerwood from the National Institutes of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, USA.
"This is particularly encouraging because those at greatest risk of Ebola live primarily in Africa, and diminished vaccine protection in African populations has been seen for other diseases."
Scientists from the NIAID developed the DNA vaccines that code for Ebola virus proteins from the Zaire and Sudan strains and the Marburg virus protein.
The vaccines contain the construction plans for the proteins on the outer surface of the virus. Immune responses against these proteins have shown to be highly protective in non-human primate models.
In this phase 1 trial, the Makerere University Walter Reed Program enrolled 108 healthy adults aged between 18 and 50 from Kampala, Uganda between November, 2009 and April, 2010.
Each volunteer was randomly assigned to receive an intramuscular injection of either the Ebola vaccine (30 volunteers), Marburg vaccine (30), both vaccines (30), or placebo (18) at the start of the study, and again 4 weeks and 8 weeks later.
The vaccines given separately and together were safe and stimulated an immune response in the form of neutralising antibodies and T-cells against the virus proteins. Four weeks after the third injection, just over half of the volunteers (57 per cent; 17 of 30) had an antibody response to the Ebola Zaire protein as did 14 of 30 participants who received both the Ebola and Marburg vaccines. However, the antibodies were not long-lasting and returned to undetectable levels within 11 months of vaccination.
Both DNA vaccines were well tolerated in Ugandan adults with similar numbers of local and systemic reactions reported in all groups. Only one serious adverse event (neutropenia; low white blood cell count) was reported in a Marburg vaccine only recipient, but was not thought to be vaccine related.
According to Dr Ledgerwood, "These findings have already formed the basis of a more potent vaccine, delivered using a harmless chimpanzee cold virus, which is undergoing trials in the USA, UK, Mali, and Uganda in response to the ongoing Ebola virus outbreak."
Writing in a linked Comment, Dr Saranya Sridhar from the Jenner Institute at the University of Oxford in the UK says, "[This] study deserves to be the focal point around which the broader question of vaccine development, particularly for Africa, must be addressed. With the uncharitable benefit of hindsight in view of the evolving 2014 Ebola outbreak, we must ask ourselves whether a filovirus vaccine should have been in more advanced clinical development.
The international response to the present Ebola outbreak is an exemplar of the speed and purpose with which clinical vaccine development can progress and has set the benchmark against which future vaccine development must be judged. This study is the first step on the aspirational road towards the deployment of filovirus vaccines in Africa and must serve to shake the metaphorical cobwebs that can stall our advance towards this destination."
Meanwhile, although Nigeria has been declared Ebola free by the World Health Organization (WHO), a recent study conducted by the Urban Action Group of the department of Mass Communication, University of Lagos has urged the Nigerian media to step up its interpretative and investigative reportage on disease outbreak, to serve as reminders and a tool for effective prevention and control of the virus in the country.
The study also revealed that the frequency and prominence of the reports by the media played a great role in curbing the spread of the virus in Nigeria.
The group, which gathered and analysed data on the reportage of the outbreak in four national newspapers, isolated a total of 719 published reports within the six-month period under study.The analysisalso revealed that an average of four news items were published per day.
According to the research, the national newspapers in Nigeria have thus fulfilled their social responsibility functions of informing the public about the outbreak of EVD and revealing precautionary measuresto curtail the spread.
However, in the area of interpretation, the study revealed that newspapers have not done so much, because only 26 per cent of reportagewas devoted to the interpretation and analysis of the disease. This is significantly low for a globally noted disease with a high mortality rate.
Founded on two social science theories of Agenda Setting and Social Responsibility, the research understudied the national newspapers in Nigeria and evaluated their ability to facilitate effective control and management of the virus in terms of reportage and analysis.
Besides, only 11 per cent of the newspaper reportage was on the front and back pages. This implies that Nigerian newspapers did not attach much prominence to the coverage of the EVD, probably because of other news items contending for attention, such as insecurity and politics.
The study also pointed out that prior to the outbreak of EVD in Nigeria, only 0.1 per cent was devoted to the reportage of the disease.
The implication, the study reasoned, might be responsible for the haphazard approach the government and entire populace reacted to it.
The study stated: "It also reflects the lack of proactiveness by Nigerian newspapers because EVD was already prevalent in West African countries close to Nigerian borders."
Also identified was another low reportage of 2 per cent on EVD in the month of July when the index case was recorded. Meanwhile, in the month of August after the federal government addressed a press conference on the outbreak, a large space was devoted to the coverage of the disease with 50 per cent of the total news coverage in the months of study. It however began to drop to 30 per cent in the following month of September after the index case had died.
The study also indicated that "by October, prior to the World Health Organization declaring Nigeria Ebola-free, news reportage dropped to 17.9 per cent, which should not have been so, because Nigeria was still at a critical point since the vaccine/cure for the virus had not been found. Our land borders also remained porous, making the country still susceptible to a re-emergence of the EVD."
Based on the findings, the study recommended that Nigerian Newspapers should step up their role in interpretative and Investigative reportage on disease outbreaks.
Other issues highlighted in the study include the need for proper training of journalists, with continuous capacity building on social development issues; communities should been couraged to establish local print media with up-to-date functional libraries for information access and dissemination; Government should also take keen interest in health management by providing appropriate policies that can ensure easy access to medical aid at subsidized rate.
