The Ever-Changing Information re pandemic influenza H1N1:
Why all the fuss?
The influenza virus goes through 2 forms of change. The typical one is "drift" where the virus goes through minor changes which force us to change the vaccine on a yearly basis. The second, and rarer, change is a "shift" where the vaccine goes through dra¬matic change which means that no one has had previous experience with that virus. This puts the entire population, on a global level, at risk.
When was the last major swine flu outbreak?
Although there have been minor problems in the 60's and 70's, the last major outbreak was the great flu pandemic of 1918 which was re¬sponsible for many millions of deaths around the world.
Is this the influenza epidemic people have been discussing for the past 5-10 years?
NO. That was the H5N1 avian flu virus that has been feared until now as the likely candidate for pandemic flu.
How dangerous is H1N1 flu?
We're not really sure. Although there have been deaths re¬ported, we don't know what the total number of infected individuals has actually been. What has been interesting (and potentially ominous) is that the greatest number of deaths has been in young adults. One possible explanation could be that these are the people most likely to have been working with infected pigs. The more ominous explanation relates back to the 1918 pan¬demic when the highest death rates were not in the very young or very old but, rather, in those in their 20's and 30's. The explanation appears to be related to a cytokine storm, a situation where those with the most robust immune systems basically caused death while fighting off the infection.
Why all the fear when the disease seems so mild in the U.S.?
First, it is an entirely new in¬fluenza virus which puts us all at risk. In spite of the mild disease noted in most cased in the U.S. so far, there is no guarantee that this will be the case as the months pass. In fact, the first wave of pandemic flu in 1918 showed up as relatively mild disease with few deaths in the spring of 1918. By the time it returned that fall and winter, it had transformed itself into a lethal disease, and not just in those at greatest risk in normal years.
What about the masks?
There appears to be some benefit only when the infected person wears the mask and wants to prevent the spread to others. On the other hand, there appears to be little if any benefit to others in the community.
Will there be a vaccine?
The short answer is "yes". It may take 5 or 6 months and will not be included in the regular flu vaccine. In addition, it is not yet known if this will require one dose or two though most companies are planning on a 2 dose schedule. If the vaccine truly requires two doses, it will create greater diffi¬culty in terms of number of doses required for the population as well as for the actual logistics.
Update as of 6/30/09:
The most recent data shows the U.S. with the largest number of deaths (about 130) followed closely by Mexico. Of great interest are the reports that Argentina now has had more deaths reported than Canada, although still less than 20. In addition, there are now significant outbreaks reported in Chile as well as Australia. Therefore, the hope that the disease would “fizzle out” in the southern hemisphere does not appear to be the case.
One other area of concern was the presence of Tamiflu-resistant influenza A this past winter. Some worried that this might possibly occur with H1N1 with devastating consequences. In reality, this has actually occurred in Scandinavia with one reported case so far. Hopefully, the lack of widespread reports of this isolate means that this bug is not highly contagious at this time.
Please keep in mind: These thoughts are factual as of the moment. This is a rapidly changing disease so much may change in the days, weeks and months ahead.