Perhaps there is a more current bird flu thread but in my browsing I found this one and thought an update was in order.
I've just realised I don't know the answer to a very simple question. Why is it intrinsically more of a problem to produce the H5N1 vaccine, assuming we will need it, than it is for the usual annual best guess vaccine type.
Dynamic's post is most informative but there is an additional problem with this vaccine. Flu vaccines also build on previous vaccinations or past infection. With no recent human exposure to H5 influenza there is no previous immunity to build on. For that reason current vaccine research is finding a higher dose as well as 2 doses are needed to produce sufficient immunity. The problem becomes decreased numbers of doses available. There is a possibility of vaccinating people with the current H5 vaccine strain with the idea it will act as a first dose and only one more dose will be needed even if the formulation changes somewhat when the virus emerges as a human disease.
But all of that is speculation and relies on the disease emerging much later rather than earlier. Current vaccine production takes several months and there is limited production capacity in the world currently up and running. Newer vaccine production methods are years away from being ready for use and they will include the same problems, you need the machinery not just the plans.
Tamiflu and Relenza have the same problem. They are made in a complex production facility of which there is currently not enough capacity. You can make all the vaccine and anti-virals the world's pharmaceutical companies are capable of and according to the vaccine manufacturers you'll have enough for 5% of the world's population in 6 months.
Capsid said:
Producing the highly pathogenic "wild type" is dubiously untenable, unless you actually want to start the next pandemic and even the attenuated variants must be handled at containment level 2. Also, within Europe, these attenuated stains are classed as GMO's, so there are more hoops to jump through and then there are the IP issues of course, which relate to the organisations that developed the methodology.
The risk of unleashing a mutated vaccine variant that is deadly is just patently incorrect. Isolation procedures in production are as much to keep the vaccine pure as to prevent its escape. The wild flu has a much greater risk of mutating than do the vaccine strains. The strains being used by the WHO for their immune response match to H5N1 are not close enough to the actual H5N1 genetically to be a special risk.
Reconstituting the H1N1 that caused the 1918 pandemic was however, very risky. But too late, it's been done now.
Some more recent revelations about H5N1 are not reassuring. The current strain needs only a couple of nucleic acid substitutions on a key gene to make it transmissible from human to human. What appears to be the case now is the virus can infect cells deep in the lung. Human flu virus strains with those 2 nucleic acid substitutions infect upper airway cells more readily.
The logical hypothesis is that when only deep lung tissue is the viruses' target, it is harder to get infected. You need to be exposed to more virus or for a longer time or under certain conditions that are less common. And, with the virus mainly replicating deep in the lung an infected person sheds much less virus so is not transmitting the infection easily to the next person who also needs virus to reach the inner lung tissue to start reproducing.
Poorly informed individuals have drawn the conclusion that since H5N1 has been circulating since 1996 without those substitutions having occurred they are not likely to occur. There may be some as yet unknown reason why H5 viral strains have not become common human pathogens. But don't count on it.
The massive bird pandemic which has spread to 3 continents in a matter of months is unprecedented in its lethality and in its ability to infect multiple species. There have been 9 mammals and countless species of birds infected so far almost all with very high mortality rates. A few bird species have managed to get infected with low mortality, but that's bad because they then spread the disease further. All measures to contain the disease in third world countries have essentially failed. In Europe they have been able to limit outbreaks on commercial bird farms so far, but that only protects the poultry industry. It doesn't limit the risk of human infection emerging in countries that aren't able to control the disease.
So what about how lethal is it really to humans? Right now the fatality rate is a little >50%. And it looks like that is the actual rate. Some, though not enough, population studies have been carried out that measured antibody to H5N1 in the populations that have experienced cases. With the exception of a few unrecognized cases in China, almost no antibody has turned up in people. What that means is the cases we have seen may very well be most all the cases there have been. The good news is the disease isn't spreading much among humans. The bad news is it is indeed as lethal as it appears.
With little control in third world countries we can expect more human cases. With each new human case there is an additional risk of those nucleic acid substitutions occurring. And occurring unnoticed until a number of people begin spreading the disease. It is estimated that if you can catch it within 3 weeks of it first appearing you may be able to stamp it out. Any longer and it's too late. With poultry outbreaks we haven't yet caught them in third world countries soon enough to stop the spread of the disease. It is now in countries least able to deal with it. Even with funds, the infrastructure just isn't there.
So you can believe it is hype and there is little evidence H5 flu strains ever become human pathogens. There is some evidence that supports that. Or you can believe there are all the conditions now in place for a deadly pandemic and it is only a matter of time. There is a bit more evidence supporting this conclusion. Either way we just wait and see.
Don't count on it only occurring during the typical winter flu season. Remember it is winter in the southern hemisphere when it is summer here. A flu pandemic will not follow a normal season pattern. I would say it is likely to be a least a few months and maybe even years away. It is also likely we'll see sporadic outbreaks before the big one. You won't catch it if you stay home. That will probably be the most effective control measure besides face shields and hand washing. Don't just use a mask, BTW. You need to also cover your eyes. We know some flu strains enter through the eye into the tear duct and then into the throat.
On that cheery note.....see ya.
Echinacea has never done anything for me, and I am somewhat allergic to elderberry so I would rather not take that either. By the time I'm sick enough to wish I had tried it anyway, I'll be too far along for that anti-viral to have any benefit.
