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Ebola Vaccine Human Trials Begin
securitas writes "The Washington Post reports on the first human to be injected with '100 trillion strands of synthetic' Ebola DNA. The DNA in the vaccine has been bioengineered by Vical to remove 'the part that triggers illness and the part that might allow the DNA to recombine with the DNA of some other virus.' The New York Times, AP via ABC and BBC all have stories about the new vaccine as the WHO reports 11 dead in a new Ebola outbreak in Congo this week. If you're interested in participating in the Ebola clinical trials, the NIH needs 27 volunteers. The study only has two. Best quote comes from the NIH vaccine center's nursing director: 'People freak out about Ebola.' Slashdot previously discussed an Ebola/HIV gene therapy."
Wouldn't a better idea be to seek volunteers in Congo - in high risk areas? Possibly near the area of the outbreak (/as soon as the next one starts so as to also try and prevent the spread of infection). Otherwise are they planning to infect the volunteers with Ebola... and don't expect anything to go wrong?
On the unethical side - if anything goes wrong it's not like the settlement in Congo will be remotely what it's in the west. People are probably less "freaked out"/don't understand the dangers, so volunteers would be easier to find. -- not that I support these reasons,
Well, given that ...
am I the only one that isn't surprised that people "freak out" about it?Avantslash - View Slashdot cleanly on your mobile phone.
The candidate vaccine is synthesized using modified, inactivated genes from Ebola virus. This gives the immune system information about viral structures so that it can mount a rapid defense should the real virus ever be encountered. There is no infectious material in the vaccine, and the virus was not present during any stage of the manufacturing process
It's not made from the virus. Only some genes that cannot induce the disease are used.
Save the bandwidth. Don't use sigs!
This is a Phase I clinical trial. There are typically 3 phases to each clinical trial, with Phase III being "official" statistical study. Phase III is "gold standard" FDA phase, where you prove statistically that your treatment works.
What is a Phase I trial? It is typically used to determine a maximum tolerable dose (MTD). And how is that done? Something called "dose escalation" is used. That means you start off with a very low dose typically given to 3 patients, and if no toxicities (bad things) happen, you raise the dose. You keep doing this until you observe two toxicities in two consecutive groups (typically). Many times the volunteers in Phase I trials are terminally ill and willing to try anything.
If you are not terminally ill, perhaps waiting for the Phase III trial to join is the best bet, when they have already figured out the "maximum tolerable dose".
Dude, I so knew that Biology degree would pay off.
Ebola, as viruses go, is incredibly hard to contract. It lacks a carrier state, which means that contraction depends entirely on contact with infected secretions. Unless you're exchanging spit, bodily fluids, or blood, you're safe. As for the vaccine, stating that the "part that causes the virus to replicate" is removed if superfluous. A vaccine by its very nature is a pathogen modified to restrict replication, and in the case of Ebola, that means the ability to attch itself to your RNA, and manifest itself. The only danger from the vaccine would be isolated to the vaccine itself, NOT Ebola Hemorrhagic Fever.
In the article it specifically notes "Volunteers will not be exposed to Ebola virus." No live virus was involved in the manufacturing process either.
Because of the ethical problems involved in any human clinical trial with real live virus, they'll probably use the "two-animal" rule in that if it protects at least two animal species from the virus, it's considered valid. Once this study proves safety, then it'll be licensed. The real trial would begin if they ever use this in the next Ebola outbreak.
My uncle is a quiet and reserved guy. He works with highly infectious agents as his job - space suits and special rooms - that whole deal.
For Christmas back in the day he gave me The Hot Zone by Richard Preston. I read it that weekend and then asked him about ebola - my uncle is one of the team that they send to the part of the world that is having some new outbreak - ebola is one of his specialties.
He was in the Peace Corps in Zaire back when then first discovered ebola, and even met his wife that way when they were both in the same tent recovering from malaria.
He said ebola was really nothing to worry about since it killed its host so fast. He said that it was indeed a bad thing if you ever got it, and it does need to be contained, but it dies very quickly outside of its host, and it kills its host too quickly.
He also noted that AIDS isn't particularly impressive either. It dies quickly outside of the person as well.
He isn't discounting the viruses by any means - just in terms of the scary stuff that he works with, he wasn't as scared by those and they are on different containment levels than other things.
He mentioned smallpox as being horrible.
I am now finishing up Richard Preston's The Demon in the Freezer and I must say that it is very interesting (his books all seem to be written in a way that you can finish them in an unnerving weekend).
Smallpox in itself is scary stuff, and then the bioengineered completely resistant smallpox is really freaky.
Anthrax is nothing compared to this stuff - anthrax can kill its host, but it is not contagious from that sick host - if someone with anthrax coughs in the same room as you, you don't then get anthrax. Whereas one person with smallpox can infect an extremely large area around them very quickly - and they don't necessarily show any signs of having it but are capable of spreading it in the first few days of being infected.
Personally, I would much rather die of a drug overdose while having sex with supermodels than have to die of any of these viruses.
Hopefully the chances of either being my final exit are equally slim.
There are some odd things afoot now, in the Villa Straylight.
The very last line of the article, hanging out all by itself:
Scientists might test the vaccine in an outbreak of Ebola under emergency conditions.
There was a very intruiging article in the New Yorker awhile back about just this subject: testing HIV/AIDS vaccines and other pharmaceuticals on Africans. Unfortunately it's not available online, and I wouldn't want to go into any more detail and risk being -1 Offtopic. But here's a short summary of the article.
What is a Virus? How does it work?
A virus is a protein sheath (called a capsid) covering genetic information. The protein sheath varies in size and shape, the most famous being the T4 Bacteriophage (picture on the bar on the left). Simply put, the genetic information can be in the form of RNA or DNA. The virus latches onto a host cell and injects its genetic material through the plasma membrane.
Viruses all have different strategies at this point, depending on their structure and target cells.
The most insidious, the retroviruses (of HIV fame), incorporate their genome into the host cell's. When the host cell copies its own DNA, in the process of normal cell division, it copies the code for the virus. Each daughter cell resulting from this mitotic division carries the virus latent in its own DNA. They now, in their normal life cycle, become factories for the retrovirus, pumping out more and more protein encased genetic sequences. Propagation is very thorough.
A simpler virus might only borrow the mechanisms of the cell to replicate itself. The virus would use DNA polymerases and associated enzymes to copy the genome for the viral offspring and RNA polymerase to transcribe mRNA molecules to translate to proteins for the viral capsid. The baby virii are then assembled (the DNA wrapped in the protective capsid) and they exit the cell. Sometimes this results in the death of the cell, other times it does not. The virus doesn't much care whether the cell survives once it has been copied.
The body, however, doesn't take kindly to its cells being hijacked. It doesn't matter if the viral infection doesn't result in the death of any cells. An infection is inefficient; a virus uses a lot of the cell's energy, energy that could be better spent in normal functions. Here's where the immune system comes in.
How does my immune system protect me from Ebola ?
Proteins are the real workhorses in cellular biology. As far as molecules go they're about as diverse as it gets; almost everything a cell does it does with proteins. A protein is coded for by a gene, a sequence of base pairs in the genome. When we make a protein we tend to make more than one at a time (one type of protein, multiple copies). One or more copies in the set get paired with another protein. This other protein, called MHC, has the sole purpose of escorting its pair to the surface of the cell and holding it there. The surface of the cell has hundreds of proteins of various types sticking out. When a virus instructs a cell to make its proteins the cell follows normal procedure and sends some of them to the surface.
The immune system is incredibly complicated. A subset of it is the T cells, which are themselves divided into two groups, Helper T Cells and Cytotoxic T Cells. Cytotoxic T cells are easier to describe; they're often called assassin cells or natural killer cells. Their purpose is to kill anything foreign that they find in the body. The Helper T Cells each have proteins on their surface (called antibodies) that recognize one target (called an antigen). They wander around, checking out all of the other cells in the body, looking for a match. If a Helper T Cell was looking for EVP-1(Evil Virus Protein 1) it would ignore every cell that didn't display EVP-1 on its surface.
If they find a match they know that the cell is infected with Evil Virus, and they signal for the Cytotoxic cells to come do their job. They also reproduce. So imagine you have a million Helper T Cells with random antibodies on their surface. You're betting on the one cell that is looking for EVP-1 into a cell that happens to be infected with a Ev
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"Little genetic errors"?
They're removing two whole genes. Viruses only have several to begin with. Your own junk DNA is littered with the DNA of several thousand extinct endogenous retroviruses that have lost one or two critical genes. Ebola, being a filovirus, lacks reverse transcriptase and cannot even look forward to a career as a dormant junk DNA sequence.
Your body sees the proteins expressed by the foreign DNA, creates antibodies, and that's it. The DNA does not replicate. Evolution requires successive copying operations (paired with natural selection) and does not apply to this process.