DNA Vaccines
There are recent reports indicating that DNA vaccines may be effective against H5N1. I believe these reports are important for several reasons.
At this point, I should explain a little bit about what a DNA vaccine is and how it differs from other vaccines. Conventional vaccines use either protein from killed virus or attenuated viruses to stimulate the immune system. Unlike most vaccines, DNA vaccines are, well, DNA., specifically plasmid DNA. Using special enzymes that recognize specific sequences, it is possible to cut and paste foreign DNA into plasmid DNA. This artificial construct can then be introduced into bacterial cells. The bacteria are incubated overnight where they divide like crazy. The plasmid DNA replicates along with the bacteria. The next day, the plasmid DNA is purified from the bacteria. Although this sounds complicated, it’s really quite easy. There are kits that allow you to do this as easily as baking a cake (almost). A semi-bright high school student can be taught to do this. This procedure is done in almost every molecular biology lab in the world, both academic and commercial.
The plasmid construct used for DNA vaccines contains one or two of the genomic sequences of the virus of interest. They are put into a special type of plasmid called an expression vector. The idea is to introduce the construct into cells and get the cells to make viral proteins. This is very different from killed virus vaccines in which case dead protein is injected into your arm. It is also different from FluMist, in which case weakened, but live, virus is squirted up your nose.
Virus for dead protein vaccines typically comes from chicken eggs. More recently, there have been attempts to get viral proteins from insect or mammalian cultures. The newer approach will shave a bit of time off the egg approach, but not enough to of much use for the first wave of a pandemic. I received FluMist this year (and last) because it has been reported to provide better protection than killed virus. However, I have some concerns about the use of attenuated virus for a pandemic strain. It is possible that mutations could occur in the attenuated virus which would allow it to revert to the wild type strain. Not really too scary if you’re being vaccinated with H3N2, but of considerable concern if the vaccine is H5N1. The other concern I have about attenuated viruses is the possibility that they might re-assort with another flu virus if a person is already infected with another subtype. Again, not a concern with H3N2, but a big concern with H5N1.
Are there any dangers with DNA vaccines? Probably, but at this point, the risks seem to be relatively small. In gene therapy, expression vectors are also introduced into people’s cells. There have been instances when the vectors have integrated into segments of the patients genome that resulted in cancer (the same vectors also saved the lives of a number of children and completely cured their disease). However, DNA vaccines differ from conventional gene therapy in that DNA vaccines use circular plasmids which do not integrate into a patients genome. In gene therapy, OTOH the goal is to integrate the construct into the patients genome to replace a defective gene. As long as “naked” DNA is used, and not viral vectors, I would think the risk of getting cancer from a DNA vaccine would be extremely low.
Under normal circumstances, DNA vaccines would be tested for many years before being approved for routine use in patients. However, if a very severe pandemic were to occur, I would expect that trials in humans would be greatly accelerated. Frankly, I don’t think we should wait until then. And if there are any clinical trials for an H5N1 DNA vaccine, I’m available.
References
Single Injection Of Vical’s Avian Flu DNA Vaccine Provides 100% Protection In Ferrets
Vaccine Against H5N1 (Avian Influenza) Manufactured For Clinical Development, PowderMed
For further explanation of how a DNA vaccine works you can go to Vicals Core Technology page. If you scroll down to the bottom of the page and click on Building DNA vaccines you’ll get a nice graphic slide show.
Disclosure
I do not receive any funding from any DNA vaccine company. I own no individual company stock - just some mutual funds which will probably be worthless ten minutes after the pandemic starts.
Monotreme. Maybe we could get the ‘fatheads’ over at effect measure to come and tell us the way it is…as we are just pretenders…good to bow and grovel.
An old veterinarian gave my fourth year class in veterinary college a talk…he said just remember one thing when you go out to practise…when you lose confidence in yourself…you make it unanimous.
The bunch on effect measure (posters not Revere themselves) take this statement to a whole other level.
Having mentioned it, I figured I might as well post what I was talking about. ……………………………………………………………..
My dear Monotone, “We” have been involved in the quest and the funding of Biotechnology and “DNA solutions” since the eighties.
I could be wrong, but I get a feeling from your youthful, “witty” and patronising tone, that you were more interested at that time, in other things.
Not a problem.
I am used to lots of great brains carrying on manual theoretical manipulations of their minds, while we get on with trying to find a real time solution to the problems.
We value our privacy and normally we keep a very low profile and try not to attract the attention of experts in the various fields, such as your self.
However, the world has changed a lot and we may have no choice but to open up a bit, if we are going to be able to add the best possible talent to any of our future projects. Not too happy with that though!
Effect Measure today.
Personally, I will put Monotreme up against any virologist in the world, any day of the week…
…and when you want someone to go down the dark alley with you…count me in!!
Sorry for messing up your thread but it was too funny not to comment…I couldn’t resist.
Puffballs!!
Tom DVM,
I just responded over at Effect Measure. I don’t think the person(s) who posted are real scientists. Sounds like a front for yet another snake oil company. Expect an ad for magical anti-flu beans in the near future.
Well, now that I have completely wrecked this thread anyway. Monotreme, we haven’t heard your opinions on what you have seen in the latest sequences released…was there anything interesting.Thanks.
Tom DVM,
I haven’t had time to look lately. I think my last comment on the sequence subject was the fact that some of the human sequences in Indonesia more closely resembled a cat sequence than sequences from other humans. Which re-inforced my view that there is a mammalian reservoir in Indonesia and probably elsewhere too.
Thank you for informing us about the potential of DNA vaccine. That makes my PPF lower a full quarter point (doesn’t sound like much, but, believe me, I’m grateful).
Olymom – at 22:53
You’re welcome. My own PPF also went down when I heard about the Vical results. Ferrets are a good model for H5N1 influenza. If the vaccine works in ferrets, there’s a very good chance it will work in people.
That being said, I would like to see the Vical results verified by an independent group. I have no plans to stop my very considerable preps. I will also continue to strongly urge community preps. We should not rely on any one strategy. Multiple approaches are the only way to survive a very severe pandemic, IMO.
OK… A couple of things……
LOL… to the Effect Measure response by Monotreme. (high five)
Next… a couple of questions…
1. DNA = Double stranded… RNA = single stranded. They use RNA viral sequences (2 influenza’s and 1 H5) to make DNA plasmid protein. Is this right? This plasmid protein (DNA vaccine) is injected into the body… which then goes into the body’s cells… The DNA vaccine then “unzips” into RNA? or not? Does this DNA vaccine replicate? Or is it just acting as a foriegn body to ellicit an immune response?
2. Is there a nucleus with this DNA Plasmid protein?
Just wondering….
FloridaGirl – at 23:03
Thanks.
RNA viruses are not my area, but I assume the H5N1 RNA is reverse-transcribed to cDNA. There are kits for this too. This cDNA is inserted into a plasmid DNA. The plasmid DNA is introduced into human cells via injection with a turbuculin syringe or fancier presure methods. The plasmid DNA is tranported to the nucleus of the cells, but does not get into human chromosomes. This is the difference between DNA vaccines and Gene Therapy. If I understand the companies somewhat vague desciptions on this point, they are achieving transient transfections, not stable ones. This means that after about 48 hours the plasmid DNA will be degraded. Before then, the human cell’s own machinery will transcribe messenger RNA from the plasmid. This message will leave the nucleus and enter the cytoplasm where it will be translated to protein. Thus, our cells will make H5N1 proteins (but not all all of them!). These viral proteins will be translocated to the surface of the cell where they will be introduced to our immune systems. Our immune system will thus get a “head’s up” regarding H5N1. Forewarned is fore-armed. We will then be vaccinated.
“My dear Monotone,” ….. (from comments at Effect Measure)
That was hilarious. Thanks for the heads-up.
Sad to see opportunists setting themselves up to try to take advantage of scared people however. I suspect we’ll see many more like this as this thing continues to progress.
Montoreme – at 23:18
My Biology and microbiology are a little rusty tonight… (gotta be the 20 hour days I am keeping, lately.)
I looked this up, because I wanted to be sure I remembered somewhat correctly.
From the Wikipedia site:
http://en.wikipedia.org/wiki/Cell_nucleus
“Specialized export proteins exist for translocation of mature mRNA and tRNA to the cytoplasm after post-transcriptional modification is complete. This quality-control mechanism is important due to the these molecules’ central role in protein translation; mis-expression of a protein due to incomplete excision of exons or mis-incorporation of amino acids could have negative consequences for the cell; thus incompletely modified RNA that reaches the cytoplasm is degraded rather than used in translation. [3]
My questions for you (even though this is not your specialty) :)
On degradation…
1. If the mRNA is not “properly prepared” (so to speak) in order for it to degrade as planned, this would not allow the message to be sent in the form of the protein expression. Is there another cause for the mRNA to degrade once it is inside the cytoplasm and the message is sent?
2. If the DNA inside the cell is degraded, what sends the signal for it to degrade? Is it self programed? an enzyme from the human cell? If there was an exterior signal, would it not also affect the Human DNA inside the cell causing cell death?
Monotreme:
H5N1 does not seem to be the best virus to try a new technique (DNA Vaccine) on to me. But hey, the CDC is investigating Morgellions disease now so if people get a creepy crawly feeling there is a treatment coming in the near future. Me, I’d rather just face off with H5N1--the odds are in my favor. I think we are not where we should be in understanding a DNA vaccine at this time with millions willing to give it a go. Frankly, I’m starting to find science to be a bit too freaky for me.
Leo7,
The science is self-evident. We know that DNA vaccines are unlikely to be purified.
It’s the science communities willingness to ignore the facts that is a bit too freaky as you’ve said.
There are no shortcuts. The community knows there are no shortcuts, but for some reason, they still turn down that blind alley . . . hoping?????
FloridaGirl – at 00:03
1. If the mRNA is not “properly prepared” (so to speak) in order for it to degrade as planned, this would not allow the message to be sent in the form of the protein expression. Is there another cause for the mRNA to degrade once it is inside the cytoplasm and the message is sent?
2. If the DNA inside the cell is degraded, what sends the signal for it to degrade? Is it self programed? an enzyme from the human cell? If there was an exterior signal, would it not also affect the Human DNA inside the cell causing cell death?
Our cells are invaded by foreign RNA and DNA all the time. You may not know this, but you are part virus! Nothing personal, but all humans have a surprisingly high percentage of viral DNA contained within our genomes; ancient relics of past attempts to hijack our cellular machinery that got into germ cells and have been passed down during the millenia of mammalian and human evolution. Pretty cool, once you get past the yuck factor.
In any case, as a result, our cells have evolved methods to detect and attack foreign nucleotides. We ooze with RNAses, enzymes that destroy RNA on contact. We’ve got DNAses too. In any case, plasmids are eventually recognized as foreign and destroyed. Presumably there is a way for our cells to distinguish between foreign and native DNA, but I don’t know much about this. Some viruses, especially retroviruses, are able to insert themselves into our genomic DNA. Sometimes these are recognized and shut off, but sometimes they aren’t. HIV/AIDS is one of the unfortunate instances of the latter. In the longer view, viral elements that have been incorporated in our genomes may actually be beneficial.
Reference
Retroelements and the human genome: New perspectives on an old relation
Leo7 – at 01:24
Me, I’d rather just face off with H5N1—the odds are in my favor.
Are you sure about that? Suppose a DNA vaccine was offered to nurses in China, where the pandemic started. Some took it, some declined. If all the nurses who got it lived and all the nurses who didn’t died coughing up blood on their loved ones, would you rethink your position?
I think we are not where we should be in understanding a DNA vaccine at this time with millions willing to give it a go. Frankly, I’m starting to find science to be a bit too freaky for me.
Ouch, as a full-time scientist, that hurts. Just remember that at the turn of the century, the average life-expectancy was about 40. That’s what life was like without medical science. Go to any grave-yard of that time and you’ll notice the many small tombstones with “Angel” engravings. A lot of kids died pre-vaccine era.
Washing hands with soap before surgery used to be considered “weird” and unnecessary. Aneasethesia had been invented long before it was used in surgery becuase it was considered unnatural to remove someone’s pain. Antibiotics were considered strange; to this day their use is forbidden by some religions. The first transplants were violently opposed as unnatural, etc, etc, etc.
We fear what we do not understand. DNA vaccines may sound scary, but if you use plasmids every day, as I do, you see them as just another tool, like a hammer.
None of this is to say that you shouldn’t be skeptical. All good fluwikians are natural-born skeptics, including me. Unfortunately, the drug companies have given us reason to be skeptical. They hid bad results and brought drugs to market that they knew were not safe. This has decreased their credibility. This is one reason I would like to see the Vical vaccine independently tested. I don’t trust any companies assurances regarding the safety and effectiveness of their new products. However, if independent studies show that Vical is effective in ferrets and safe in humans, we’d be crazy not to use this tool in the event of a very severe pandemic. It’s the only hope many people would have of survival.
NS1 – at 04:31
The science is self-evident. We know that DNA vaccines are unlikely to be purified.
Huh? Plasmid DNA is purified everyday in my lab and in thousands like it. There are special kits that remove endotoxins if you’re going to use it to transfect cells. I assume purification is even more stringent for injection to humans, but this is not rocket science. Pretty simple chemistry, really.
It’s the science communities willingness to ignore the facts that is a bit too freaky as you’ve said.
Well, I’m a scientist. How about listing the facts me and my colleagues are ignoring. btw, how did we invent antibiotics, put a man on the moon, develop high blood pressure medication, figure out how to cure most cases of Hodgkins lymphoma and on and on…Was it by ignoring “the facts”?
There are no shortcuts. The community knows there are no shortcuts, but for some reason, they still turn down that blind alley . . . hoping?????
Shortcuts! Shortcuts! DNA vaccines have been under development for decades. Anyone who thinks DNA vaccines is some freaky new idea, do me a favor. Go to PubMed and type in “DNA vaccine” in the search box. You will find a total of 4964 peer-reviewed papers going back to 1986. Criminy!
Monotreme mutters to himself after another long day at the lab
Monotreme— don’t worry about the muttering, sometimes it’s a way to the answer! I remember talking about DNA vacines in Micro in the 80′s,boy was that a trip through the cobwebs. Thank for posts that I can understand. I know that you could very easily lose us “regular” people. Thanks again.
Michigan Mom – at 23:24
You’re welcome. Go Blue!
I’m a nobody…BUT…I think these vaccines may be our only hope. When our chicks start dying in our arms, we will really understand the meaning of side effects. The side effect of H5 is death, almost certainly!
I have stayed in contact with a doc. at Purdue, Dr. Mittel. He should have a DNA vaccine ready to go to trial this fall and I will check with him again soon. My chicks are on his trial list. If this vaccine makes it through human trials safely, enough doses could be made, for the enitre US, in 6o days. This vaccine could be shelved ahead of time or we could pre-vaccinate. If vaccinated now, the vaccine should cover shifts in the virus for about 5 years. This vaccine uses about 1/100 of the antigen, in the current vaccines. Two million doses of this vaccine could be made in the lab at Purdue. That shows, how much easier it may be to manufacture these new vaccines. All of the trial vaccine, for the egg based H5 vaccines, have come from overseas. We may already have pharmaceutical companies, that could make this new vaccine, right here in the US. Other countries, may also be able to manufacture it as well.
The last time, I spoke to Dr. Mittel, he had an interested investor. Their hope was to manufacture and sell this vaccine, to the US citizens. Their plan was to take much of the profit and manufacture and provide vaccine, for the parts of the world, that will likely be left without. My prayers are with this dear man and his research team….I have spoken and written back and forth to him enough to know this…He is a true humanitarian!
I have to have some hope…Something more than stockpiling enough food, to eat well, while waiting for my chicks to die of this dreadful scourge!
Monotreme: Did’t mean to strike your heart, but just because you can doesn’t mean you should. I know you’re a trustworthy soul, but after you invent it then what happens? Hey, I will take DNA vaccines when and if they ever test my DNA to see which prescription drug is effective on my genetics first. They’re just guessing now..apparently. While you touched on the wonders of science there are plenty of horrors you left out. I’m not against vaccines in general, I’m against floating the idea that the human race must have a vaccine for every ailment. Would that foreign DNA you mentioned have anything to do with the previous vaccines we’ve taken?
Mom11: I typed two paragraphs and deleted them because it’s not my business. But you scare me—I’m still deleting. “It should cover shifts in the virus for five years????” Sounds like he knows more than anyone else looking at H5N1. I hear somthing quacking.
Hi Leo!
This isn’t the only vaccine, that is currently showing some promise at cross protection. Sanofi Pasteur’s preliminery vaccine results, using a Vietnam 2004, strain of the virus, is showing promise of some cross protection as well. I believe there are others, that are suspected of having this benefit.
I know what you are thinking…Yes..I would allow my children to participate, in this particular vaccine trial. Children come late into a trial and I would allow them to participate, if the adult trials were promising. I would beg for my children to be given a vaccine, even with some serious side effects, if the risk of not having the vaccine and contracting a virus, such as H5, would mean almost certain death. I don’t care how much work, I’ve put into prepping…And I think I am well prepared…I am absolutely certain, if these children are infected with this deadly virus, they will die from it. Nothing I will be able to do for them, will save them. Virtually no children survive an infection from this virus and that is with hospital care. In fact I am wondering why I’m bothering with all this dang prepping…So we can die of this thing, nice and plump! If Dr. Woodson says we are all going to breath this virus, then what’s the point…I pray for a vaccine and I would have my children take it, even if there are side effects, maybe even serious side effects…If H5 is what we would be vaccinating against and it was breathing down our necks!
Mom11:
You’re a good soul. But I’m afraid the papers regarding how the clinical trials have gone aren’t written until the whole shebang is finished. At least, ask to see the safety data that is given to the PI (primary investigator) in confidence. He probably won’t share, but it doesn’t hurt to ask. There’s no way he can be sure it will cross protect for 5 years-that’s why I made the quacking comment. He gets paid to enroll, healthy child participants are as rare as unicorns, and you don’t get paid.
Monotreme – at 22:25
Thanks…
I did know that viruses… those noticed and unnoticed… invade our space (and bodies) everyday. I am also aware that research is increasingly revealing just how much viruses become a menance to our bodies. Certain cancers are now thought (some proven or correlated to) to be caused by viruses. Also neurological disorders… BActeria play a role also…
While I am aware that bacteria plays a symbiotic relationship to the functioning of our body… Perhaps even being a major stepping stone for our evolution in the form of mitacondria. They are also responsible for helping produce certain vitamins in our body. At the same time, bacteria can be harmful, too.
That said, I am not aware of viruses becoming part of our genes over the eons. But, I am not surprised. So I wonder… Are they helpful?
Prions are also pieces of protein and found in our bodies…. But, they are usually only harmful if the prion causes disease.
I am certainly not saying that DNA vaccines are not safe… I was just curious to how they would work. (The mechanism of stimulating the immune system) I, too, would have to see some independant studies to assess their safety.
Like you said… They may be an answer. I would hope the company has time to develop and test the vaccine before a pandemic occurs. Judging from human nature of “Big Business” these days… I would always worry about a vaccine that was released under the protection of the new laws protecting pharmiceutical companies.
Mom 11. I would suggest you ask a few questions before you submit your ‘chicks’ for a trial…
1) has the investigator ijected himself and given himself a booster with the experimental vaccine and
2) has he submitted his own children to the experimental protocol and if he doesn’t have children, does he have his own relatives signed up as guineau pigs…
…if the answer is no…you take your children and run away as fast as you can.
Note: I was an experimental subject for an experimental human diploid rabies vaccine in 1981…and almost died.
It should be kept in mind that at the very worst scenario…you will have an eighty percent chance to get sick with H5N1 and walk away completely unscathed…no after-effects.
Hope that helps.
TomDVM:
They’ve created an out for themselves on your very good suggestions. They will say, “they’re not allowed to participate so they can stay objective.” It’s crapola, but it’s exactly what he will tell Mom11. I worked for a doc who when the experimental treatment went mainstream and he was in the ED a perfect candiate he opted out. I said #%$#@!? He said, “it’s dangerous.” I quit clinical research soon after. Not because he refused, it’s his right, but because I would have to lie to people from then on out. MOM11 if you ask TomDVM’s questions and he says anything close to what I typed, grab the chicks and go buy them milkshakes.
Leo7 – at 01:17
Would that foreign DNA you mentioned have anything to do with the previous vaccines we’ve taken?
No. Your great, great grandparents had the same foreign DNA. So did our knuckle-walking ancestors. So does every monkey in the zoo. We have been targets for viral invasion for a long, long time.
Labradoodle or a Pack of Wolves
It is hard for me to convey why I lack the fear of plasmid DNA that others here are obviously experiencing. It’s really because of familiarity. I have worked with plasmid DNA for many years. Many others I know have also. None of us have sprouted third eyes or tentacles ;-). Here is an analogy to convey how I think about the risk of being injected with plasmid DNA vs. being infected with H5N1.
Imagine that there is a pack ravenous wolves that has been preying on people in a neighborhood not too far from you. They are very good at not being seen until the last minute when they pounce upon families and rip them to pieces. One person in that neighborhood has discovered that Labradoodles can sniff out wolves 5 minutes before they get close. His labradoodle warned him and he got his family inside just before the wolves came. He has puppies and he is offering them to people so they to can be protected from the wolves. Would you take one? There are risks associated with taking a puppy. It might have rabies, although that’s pretty unlikely. there is a good chance it will piddle on your carpet. OTOH, the wolves are getting closer.
For me, plasmid DNA is a labradoodle; it’s a familiar “pet” that is helpful in my work. It’s possible it could cause harm, but because I understand it’s properties, I realize this is a very low risk. Not so, H5N1. It has a 50% kill rate. It enters cells, has an orgy inside our nuclei and replicates with abandon, then blasts our cells apart. People die in excruciating pain. And pass on the vile contagion to their loved ones. H5N1 is a pack of ravenous wolves in my book. I’ll take the labroodle any day of the week.
Monotreme. I have nothing but the greatest respect for your unceasing contributions to the fluwiki.
In this instance, safety concerns definitely exist regarding plasmid DNA vaccines. When reading this article, I realized that part of the concerns have also been expressed regarding genetic engineering in general.
Title: Ensuring safety of DNA vaccines. Microbial Cell Factories 2005, 4:26.
From the introduction. “Vaccination with purified plasmid DNA involves injection of the plasmid into the patient to elicit an immune response to a protein that is encoded on the plasmid [1]. This mini-review focuses upon several aspects of safety of the DNA molecule itself and of the microorganism used to manufacture the DNA. The review is not exhaustive but does raise very important safety issues to be kept in mind early in the development of DNA vaccines.”
To see quick summary of the safety concerns, click on Table 1 in the left sidebar.
This material is snipped from guidance issued by the FDA regarding plasmid DNA vaccines, published here. Some snips are included below to help people be aware of a few of the known issues involved with such products.
Guidance for Industry Considerations for Plasmid DNA Vaccines for Infectious Disease Indications
For the purposes of this document, DNA vaccines are defined as purified preparations of plasmid DNA designed to contain one or more genes from a pathogen as well as regulatory genetic elements to enable production in a bacterial host system. Typically, these plasmids possess DNA sequences necessary for selection and replication in bacteria. In addition, they contain eukaryotic promoters and enhancers as well as transcription termination/polyadenylation sequences to promote gene expression in vaccine recipients, and may contain immunomodulatory elements. snip
from “Bulk Plasmid Product Release Testing”
We recommend that you evaluate bulk plasmid preparations for the presence of bacterial host cell contaminants to include DNA, RNA, and protein and set limits for the maximum level of each of these contaminants. We generally recommend that host cell contaminants be at as low a concentration as is technically feasible. We recommend that you perform a test for pyrogenic substances and that you include the test results with the bulk release documentation. The Limulus Amebocyte Lysate (LAL) test is a sensitive indicator of the presence of bacterial endotoxins and endotoxin contamination should not exceed 5.0 EU/kg body weight for the intended recipients.
from “Autoimmunity”
The possibility persists that DNA vaccines might idiosyncratically cause or worsen organ-specific autoimmunity by encoding antigens (including cryptic antigens) that cross-react with self. Thus, we recommend that you continue to monitor the general well being of animals participating in preclinical immunogenicity and toxicity studies, and of all human trial participants. In cases of immunity developing against a transgene product (such as a cytokine), we recommend that you examine potential cross-reactivity with the corresponding endogenous protein. Studying an animal model using a construct containing the analogous animal gene is recommended to evaluate potential adverse effects.
FloridaGirl – at 18:11
The concerns you and others express regarding the role of pharmaceutical companies in designingsafe and effective vaccines prompts me to make the following suggestion.
The WHO should sponsor the construction of a DNA vaccine. The could announce a Request for Proposals (a la NIH) and use their newly formed advisory commission to award grants to several groups of investigators. These investigators would have to agree to renounce all rights to the vectors they create. All vaccines that were created as result of this work would be free to any contry or group who wanted them. The vectors would be tested by a separate group of investigators in animal challenge experiments. Vectors found to be safe and effective in animals would then be tested in humans. The goal would be to assess both safety and effectiveness of the vaccine in generating a robust immune response. Assuming the vector passes these tests, it would then be distributed to molecular biology labs all around the world for rapid amplification and purification, when needed. For countries that do not have the capacity to amplify and purify plasmids, which would not be too many, the WHO would contract out this job to a company or academic institution.
I am convinced that this is the only way we will have a vaccine for most of the world’s population in time to do any good. We can all talk about SIP, our wonderful preps and debate whether we want a DNA vaccine or not, but what about a shanty dweller in Mumbai? Are they going to SIP? No, they going to get infected and they are going to die in a very severe pandemic. Let’s not kid ourselves about that. The megacities will be piled high with corpses without a vaccine. And most denizens of megacities have absolutely no chance of getting a vaccine unless DNA vaccines can be made to work and are freely available.
Either the WHO provides a DNA vaccine for the world, or they get their erasers out and prepare to “adjust” world maps for the coming depopulation of the third world.
beehiver,
I think the safety concerns you list are legitimate. However, any new procedure has safety concerns. Pharmacologists say all drugs are poisons with beneficial side-effects. Deciding to take any medication involves weighing risks versus benefits. In general, I favor non-pharmaceutical interventions whenever possible - diet, exercise, etc. But if I need a drug, I take it.
In an ideal world, safety trials might continue for several years before H5N1 DNA vaccines would be used routinely in humans. I would not want an H3N2 DNA vaccine, right now. However, if a pandemic with a high CFR were to start tomorrow, I would run, not walk to get an H5N1 DNA vaccine. Please keep in mind that in the ferret study, all of the animals that received the DNA vaccine survived an otherwise lethal dose of H5N1. And that’s the bottom line. Life or Death.
As regards endotoxins, I am familiar with this issue. We transfect cells plasmid DNA. Endotoxins can kill cells. So, we use a kit to further purify the plasmids. Here’s one example:
Hi!
I went for my final H5 trial visit and blood tests today. I asked if any results were back and was told the very early, preliminery results were disappointing. Not many results were in, however and I believe there were 9 different combos of alum and MF59 and different percentages of the anitgen. No matter really, this isn’t THE one that our chicks would ever see…it’s egg based. This doesn’t look very promising, for trying to stretch, the small amount of vaccine we have for first responders and health care professionals, though. I will get my results in about 2 months.
I’ve thought a lot about vaccines and their risks. I’ve been told I have Lupus…If it was caused by the vaccine…If H5 were beating down the door of my chick’s home….I would knock over little old ladies, to get my babies to the front of the vaccine line….We need our best result….SOON…We need to shelve it and wait and see what the risk of the virus is, compared to the risk of the vaccine….H5 kills just about everybody, the vaccine I received, didn’t do THAT! I certainly hope that I won’t have to make the choice to give my children a vaccine, with serious side effects, in order to save them from a monster virus. I do hope, we will get a better result, then the vaccine I received, but whatever it is going to be, we need to hurry! Just because we get one, doesn’t mean we can’t continue to research and improve.
They did start today, another study. This one is a DNA vaccine and they are testing it on adults, ages 18–40. I pray it works and is safe!
Also, so there is no misunderstanding…I was never approached, nor asked by Dr. Mittel, nor anyone else at his facility, to participate in his trial. I read about his research, in Popular Science a year ago and saw hope in what I read. I contacted him and have corresponded with him, throughout the year. I offered, to be in his trial, he at no time even hinted for me to offer. He decided, after following the H5 virus, to try and adapt his research on breast cancer gene therapy to a vaccine for this virus. This man is no quack, in fact the infectious disease specialist, I am now seeing, was well aware of who he is. I understand everyone’s caution and I appreciate all the concern. I have spoken to Dr. Mittle at length, more than once. It becomes quite clear, that this is a higly intelligent, kind, humble man. I believe he may be from India, but he talks often of the deplorable conditions, many around the world live in. He understands the importance of getting a safe vaccine, that can be rapidly made, in order to stop a deadly pandemic. I have thanked this man, several times, for all his hard work and he each time, reminds me, that it isn’t him, but the US citizens, that have funded his work, through their hard work and tax dollars. I trust him…I have to have some hope!
PS….I wouldn’t really knock over little old ladies, NAH! I’d drag them with me and we’d knock over stupid husbands! NAH! I’m too small to knock over anybody!
“The possibility persists that DNA vaccines might idiosyncratically cause or worsen organ-specific autoimmunity by encoding antigens (including cryptic antigens) that cross-react with self.”
I’d also be concerned about the compliment to this: that (in an immature immune system) T cells might be “trained” to ignore viral antigens, leaving the body utterly defenseless against the virus.
Racter where have you been? There’s no debate without you. Very good point as well. In science time we just cracked The DNA code and now we’re already jumping to vaccines. Add that to we are lacking knowlege in the immune system function. I’m not as confident as Monotreme. but, I do see his idea gaining more acceptance as the reports from the norm vaccines continue to be bleak.
Racter where have you been?
I’ve been busy. I have been looking in (always) — just not willing to spend the time to compose posts. You all seem to have been doing a fine job even without my participation anyway (as amazing as that prospect is to me).
/:0)
Racter,
I don’t want to minimize possible risks of DNA vaccines. But I think it is important that, thus far, all of the risks are potential. One could argue that they are too new for negative effects to be observed, but that is true of any new treatment. Work on DNA vaccines goes back 20 years. There has been extensive discussion of possible negative effects and many of these have been dealt with in construct design (eliminating antibiotic selectable markers, etc.).
It is also worth pointing out that DNA vaccines have been tested in horses for over 5 years. From West Nile shot for horses is first licensed DNA vaccine
Work on the new vaccine began about 5 years ago at the CDC’s branch in Fort Collins, Colo. In clinical studies, the vaccine protected horses from WNV-related illness without causing any major side effects. The USDA’s Center for Veterinary Biologics determined that the vaccine’s safety and efficacy have been satisfactorily demonstrated.
There are many clinical trials with DNA vaccines currently in progress. Presumably we would have heard if there were any strongly negative effects.
The main concern I have heard regarding DNA vaccines have centered on efficacy, not safety. Thus, the fact that Vical’s DNA vaccine completely protected ferrets in challenge experiments is fantastic news, IMO.
A further note, my confidence in the relative safety of DNA vaccines applies only to the use of “naked” circular plasmids. Such vectors are very unlikely to be integrated in the host genome, IMO. The risks associated with viral vectors, adeno or lenti, are much, much higher. My bottom-line is that transient transfections have a relatively low risk, stable transfections would greatly increase risk.
A final note. IMO, the safest treatments should be reserved for pregnant women and children. This would apply to vaccines as well as any other treatments. I think it is highly likely that if a severe pandemic occurs this winter, we will have some, but not nearly enough conventional vaccine, but potentially all the DNA vaccine we could want. Under these circumstances, I would vote to give the conventional vaccine to pregnant women, babies, and young children first. When that runs out, DNA vaccine would be offered to everyone else.
bump
Monotreme – at 23:54
You wrote:
A further note, my confidence in the relative safety of DNA vaccines applies only to the use of “naked” circular plasmids. Such vectors are very unlikely to be integrated in the host genome, IMO. The risks associated with viral vectors, adeno or lenti, are much, much higher.
How would we know the difference?
FloridaGirl – at 22:39
How would we know the difference?
Well, I would ask them: “Is this this naked DNA or is the expresson cassette contained within a viral vector?”
Plasmid DNA is normally circular. Because of this, it is difficult for it to be intergrated into our chromosomes, which are linear DNA. Instead, it is expressed for a few days and is then normally degraded. It is very commonly used in this way in cells in the laboratory. I have never seen this type of DNA get integrated into chromosomes. It always stops expressing after a few days to a week. This is known as a transient transfection.
In contrast, adenovirus or lentivirus virus vectors are used in gene therapy where the intent it is to permamently replace a defective gene with a working one. In the case, you want the expression cassette integrated into your chromosomes so that you can continue making the protein that is missing from your body. This is called a stable transfection.
IMO, the risk from a transient transfection is extremely low. The risk from a stable transfection is much higher. There have been deaths as a result of gene therapy. OTOH, some children have been completely cured of otherwise lethal diseases using gene therapy. So, this field has had mixed results. IMO, gene therapy should be reserved for very serious diseases at this point. Injections with circular plasmid is *not* gene therapy. There has been alot of confusion on this point.
I think “naked” DNA vaccines are likely to be relatively safe. I would have a much higher level of concern about the safety of expression cassettes contained within viral vectors.
OK… That explains why we want the naked plasmid. I understand gene threapy’s intent. You have just explained how that works…. Thanks.
Another question… Because of the mechanism of delivery for each (very different) purpose, should I just take for granted that vaccine companies are going to use the naked plasmid to develop a DNA vaccine?
Or are you just going to give me a heads up?
I thought I would post this here…
FDA Issues Guidance on Cell-Based Vaccines
The Food and Drug Administration (FDA) issued guidance to help manufacturers develop vaccines to address emerging and pandemic threats. The draft document includes information for determining the suitability of a cell culture for manufacturing, as well as testing and validating the safety and purity of the cells used in the development and production of viral vaccines. The document also provides information on testing at different stages of production and quality-control test methods. To download the Guidance Document, go to
FloridaGirl – at 23:34
Because of the mechanism of delivery for each (very different) purpose, should I just take for granted that vaccine companies are going to use the naked plasmid to develop a DNA vaccine?
No, I would not take it for granted, I would ask. Many vaccine companies are quite vague about their technology. In the case of Vical, their diagram shows a circular plasmid so it is clear that they using naked DNA. I would still ask whether a viral vector was being used before I let anyone put anything in my arm.
Or are you just going to give me a heads up?
If I can I will, but I can’t guarantee that I’ll be in a position to do this.