formidable enemy. Ebola.
scientists have moved closer to developing a vaccine against one of the deadliest diseases known. In the November 20 issue of Nature , they say a new DNA vaccine can protect macaques develop haemorrhagic fever Ebola, a highly contagious and sometimes fatal disease that is terrorizing the sub-Saharan Africa.
Ebola causes devastating symptoms such as shock and internal bleeding. The virus can kill up to 0% of its victims, often within 10 days after infection. At present, there is an epidemic in Uganda, which has so far sickened at least 337 people and killed 121. There are no drugs for Ebola, and most scientists believe that a vaccine is the best way to protect populations at risk. But so far, efforts to develop such a vaccine have failed.
Now a team of researchers from the National Institutes of Vaccine Research Center of Health in Bethesda, Maryland, and the Centers for Disease Control and Prevention in Atlanta has developed a DNA vaccine. This type of vaccine is comprised of a piece of viral DNA - in this case, an encoding section for the virus envelope - which is injected into the muscle. The hope is that the gene will be expressed as a harmless protein and teach the immune system how to defeat the actual virus
The team vaccinated four macaque monkeys. each first received three injections with the gene in the form of a piece of "naked DNA" and a few months later, a booster consisting of an adenovirus expressing the same gene. The vaccinated monkeys developed antibodies and immune cells against the virus; moreover, they survived injected with the Ebola virus and were healthy months later. Four unvaccinated monkeys were used as control group were dead or dying in a week after the injection.
Other scientists say the results look promising, but some point out that the vaccine may have worked because the team has challenged their monkeys with a relatively low dose of Ebola virus. "I am cautiously optimistic that [this vaccine] is an important step," says virologist Alan Schmaljohn the Medical Research Institute of the US Army Infectious Diseases in Frederick, Maryland. "I will be more comfortable once it is repeated with a higher challenge dose. "
Related Sites
Ebola Hemorrhagic Fever fact sheet from the CDC
The Ebola Outbreak in Uganda
The National Institute of Allergies and infectious diseases
0 Komentar