Could the H1N1 Pandemic Be Over? Dr. John Gives us the Straight Scoop

Guest Contributor, John Bogen, MD, provides another update on the H1N1 pandemic along with his observations with what to expect in the coming year.

Photo: UCSD.edu

Since August 30, 2009, 99+% of subtyped influenza A have been novel 2009 pandemic strains (944 different strains have been identified). And so far, seasonal H1N1 and H3N2 strains have not been resurgent, and have killed very few compared to past years. If the oft-quoted 36,000 deaths annually from seasonal influenza is correct (of which 90% are elderly), then we can be thankful this season that influenza has “only” killed about 10,000 due to it’s low virulence compared to seasonal H1N1 and H3N2, and the fact that elderly have some immunity to the pandemic strain due to their birth before the 1957 pandemic when H2N2 replaced H1N1 as the dominant strain.

H1N1 Influenza Virus. Photo: CDC

The CDC website has posted weekly updates (usually on Fridays). The presentation has been quite clear.

What could have been done better? One could blame the foreign manufacturers for the delay in vaccine, which admittedly has made the vaccine have little impact on the pandemic this season, but I cut them some slack – the virus was identified in California in April, and the pandemic was not declared until June.

If you want to improve the system, you could make the case to reduce legal liability and red tape in the U.S. to encourage more vaccine manufacture in the U.S. (only the nasal version was made here this season), and encourage pharmaceutical companies to move past the slow chicken egg processes.

Eggs Being Prepared for Vaccine Production. Photo: Medirsource.com

The one thing I disagree with the official govt policy now is the strong push for healthy individuals to get vaccinated, and consume the vaccine that has already been manufactured and paid for. Herd immunity [Note: herd immunity occurs when a sufficient percentage of the population either has had the influenza, or has been vaccinated against it that there is no longer anyone left to contract the virus-DW]  is now very high due to the fact so many people contracted pandemic H1N1 already, with a smaller herd immunity effect due to the delayed vaccine. Healthy people have an extremely low mortality rate from pandemic H1N1 (most deaths were those with chronic illnesses as per usual, with a shift in absolute numbers towards younger people simply due to the fact that younger folk got so many more cases due to no innate immunity).  In my humble opinion, it is now a waste of time to vaccinate healthy individuals, and time should be spent by us PCPs on our non-vaccine duties.

I offer a prediction that the pandemic is over (i.e. no more peaks this season) in the U.S., and we will not see a resurgence until the usual influenza season next winter. I also would not be surprised if pandemic H1N1 becomes the new dominant seasonal strain in subsequent flu seasons (as happened historically after the 1957 and 1968 pandemics).

I predict the vaccine next season will be quadrivalent, containing pandemic H1N1 strains in circulation now (i.e. an update from current vaccine that contains hemagglutinin from strains present last spring / early summer), the former seasonal H1N1 and H3N2 (just in case they don’t disappear from circulation), and influenza B. I do not have info on the seasonal vaccine being prepared for the southern hemisphere’s upcoming flu season (during our summer).

I'm too cute to cause flu.What? I did? Oops, sorry! Photo Courtesy: MADMAXX174 Photo Bucket

This whole exercise was a “rehearsal” for the event that we ever get a really devastating influenza A pandemic, as would occur if H5N1 (a.k.a. bird/avian flu with it’s 60% mortality) ever co-infected an animal or human with a highly contagious influenza A virus (e.g. any H1N1 or H3N2), genetic material was exchanged, and a new virus was born. The WHO and CDC will be even better prepared for future pandemics.

One more thing, we did not know the case-fatality rate or epidemiology of pandemic H1N1 when vaccine planning was performed in spring / early summer 2009. It is better to be over-prepared than under-prepared.

It is true HIV, TB, and malaria are devastating in other parts of the world, but that is a separate debate. The issue here is did public policy officials have the appropriate response in the U.S. to the influenza pandemic (I think yes), and what have we learned to plan better for next winter’s flu season.

And to end on a light note:

Despite how silly this photo looks, it is an actual N-95 mask fitting procedure. You put on the mask securely, the hood is placed over your head and an aerosol odor is puffed into the hood. If you cannot smell the aerosol, then the mask is properly fitted. I know because I've gone though this fitting procedure--DW. Photo Courtesy: PunditKitchen.com

H1N1 Status: Updated with Latest CDC Data

Extreme Thinkover Guest Article

Dr. John Bogen, MD

Updated with the Latest CDC Data, November 12, 2009

What is the current status of the pandemic in the U.S?

The CDC reported that for Week 43 (ended October 31, 2009), both hospitalizations and deaths from influenza dipped slightly. A total of 18 pediatric deaths were reported for the week. Virologic surveillance of 14,151 specimens sent to U.S. labs for testing revealed that 37.2% tested positive for influenza, a slight decrease. Of those that tested positive, 0.3% were influenza B, and 99.7% were influenza A. Of the influenza A strains subtyped, 99.9% were the pandemic strain, and only 0.1% were strains associated with strains seen in prior seasons. http://www.cdc.gov/flu/weekly/

What do these data mean for the average patient? The seasonal influenza vaccine has so far had little value, since almost all the influenza currently circulating is the new pandemic strain. The pandemic vaccine has just now begun to be distributed and given to patients. We are still in the heart of the flu season. It is too early to tell from the data if the country itself has “peaked” in terms of the number of cases. There are also regional and local differences – some areas have already been hit hard, as evidenced by school closures. Other areas have not yet peaked. It is also too early to tell if the pandemic vaccine has made any difference in the overall numbers.

In usual “non-pandemic” influenza seasons, an estimated 36,000 deaths occur directly or indirectly from influenza in the U.S., with 90% of these in the elderly or in those with weakened immune systems. One piece of good news this season is that the elderly population seems to have some immunity to the pandemic H1N1 strain, probably due to different H1N1 strains that were in circulation until the 1957 H2N2 pandemic, at which time H2N2 replaced H1N1 as the seasonal strain. The bad news is that we are seeing more than the usual number of deaths in younger people (under age 65). People with weakened immune systems are still dying disproportionately, and we are seeing more than the usual number of deaths in previously healthy individuals including children and pregnant women.

According to a CDC report on November 12, 2009, here have been about 3,900 total deaths since the pandemic started. The estimated mortality rate has been about 0.022% for elderly, 0.024% ages 18-49, and 0.007% ages 0-17.

Data on vaccine safety are difficult to obtain at this time, since distribution of the vaccine has just begun. Several highly publicized anecdotes of serious reactions have appeared in the lay press. Most of these were with the seasonal vaccine. Ongoing clinical testing of the pandemic vaccine has continued to show good short-term safety. One must keep in mind that a temporal association between vaccine and symptom does not imply causality, but patients with serious reactions (e.g. anything more than local muscle soreness from the shot and the common few days of general malaise following the shot) can and should be reported to VAERS. It is quite obvious that, worst case scenario, that deaths from pandemic influenza greatly exceed the number of serious reactions from the vaccine.

The next few weeks will be critical. Between vaccine being distributed / administered and the pandemic running its course through communities, one would hope to see a downward trend in hospitalizations and deaths. The vast majority of unvaccinated patients who get pandemic influenza will be fine after a few days of misery. The vast majority of patients who get the vaccine prior to getting sick from pandemic influenza will not have a serious reaction to the vaccine and also will not get ill or die from the virus. If we see fewer deaths from influenza this season than the usual 36,000, that would be a good thing, but hardly a consolation to the families and friends of people who died from the pandemic.

If I may offer my educated opinion, I predict the pandemic strain will continue to be the dominant strain of influenza in the community. Next year’s seasonal influenza vaccine will include the current pandemic H1N1 strain (or a mutated version thereof that exists next spring), and influenza B. With luck, subsequent seasons will be mild because so many would have already gotten ill and developed immunity to the novel H1N1. The elderly will continue to have some natural immunity, and the vaccine and herd immunity will protect most of the rest of the population.

2009 Pandemic H1N1 Influenza A: Where Do We Stand Now?

Extreme Thinkover Guest Article

By Dr. John Bogen, MD

Updated November 8, 2009

What is the current status of the pandemic in the U.S?

The CDC reported that for Week 43 (ended October 31, 2009), both hospitalizations and deaths from influenza dipped slightly. A total of 18 pediatric deaths were reported for the week. Virologic surveillance of 14,151 specimens sent to U.S. labs for testing revealed that 37.2% tested positive for influenza, a slight decrease. Of those that tested positive, 0.3% were influenza B, and 99.7% were influenza A. Of the influenza A strains subtyped, 99.9% were the pandemic strain, and only 0.1% were strains associated with strains seen in prior seasons. http://www.cdc.gov/flu/weekly/

What do these data mean for the average patient? The seasonal influenza vaccine has so far had little use, since almost all the influenza currently circulating is the new pandemic strain. The pandemic vaccine has just now begun to be distributed and given to patients. We are still in the heart of the flu season. It is too early to tell from the data if the country itself has “peaked” in terms of the number of cases. There are also regional and local differences – some areas have already been hit hard, as evidenced by school closures. Other areas have not yet peaked. It is also too early to tell if the pandemic vaccine has made any difference in the overall numbers.

In usual “non-pandemic” influenza seasons, an estimated 36,000 deaths occur directly or indirectly from influenza in the U.S., with 90% of these in the elderly or in those with weakened immune systems. One piece of good news this season is that the elderly population seems to have some immunity to the pandemic H1N1 strain, probably due to different H1N1 strains that were in circulation until the 1957 H2N2 pandemic, at which time H2N2 replaced H1N1 as the seasonal strain. So, we are seeing far fewer total deaths, just over 1,000 (but perhaps as high as 3,000, according to other CDC data not currently publicized) since the pandemic started.

The bad news is that we are seeing more than the usual number of deaths in younger people (under age 65). People with weakened immune systems are still dying disproportionately, and we are seeing more than the usual number of deaths in previously healthy individuals including children and pregnant women.

Data on vaccine safety are difficult to obtain at this time, since distribution of the vaccine has just begun. Several highly publicized anecdotes of serious reactions have appeared in the lay press. Most of these were with the seasonal vaccine. Ongoing clinical testing of the pandemic vaccine has continued to show good short-term safety. One must keep in mind that a temporal association between vaccine and symptom does not imply causality, but patients with serious reactions (e.g. anything more than local muscle soreness from the shot and the common few days of general malaise following the shot) can and should be reported to VAERS. It is quite obvious that, worst case scenario, that deaths from pandemic influenza greatly exceed the number of serious reactions from the vaccine.

The next few weeks will be critical.

Between vaccine being distributed / administered and the pandemic running its course through communities, one would hope to see a downward trend in hospitalizations and deaths. The vast majority of unvaccinated patients who get pandemic influenza will be fine after a few days of misery. Similarly, patients who get the vaccine prior to getting sick from pandemic influenza will not have a serious reaction to the vaccine and also will not get ill or die from the virus. If we see fewer deaths this season from influenza, that would be a good thing, but hardly a consolation to the families and friends of people who died from the pandemic.

If I may offer my educated opinion, I predict we will see fewer than 10,000 deaths in the U.S. this flu season.

The overall mortality rate will “only” be approximately 0.01% (1 in 10,000). The pandemic strain will continue to be the dominant strain of influenza in the community. Next year’s seasonal influenza vaccine will include the current pandemic H1N1 strain (or a mutated version thereof that exists next spring), and influenza B. With luck, subsequent seasons will be mild because so many would have already gotten ill and developed immunity to the novel H1N1. The elderly will continue to have some natural immunity, and the vaccine and herd immunity will protect most of the rest of the population.

I Have a Cold. I Hate Colds! My Head Feels Like…

The Runny Nose has met its Match

The Runny Nose has met its Match

I have a cold.  It’s February.  I hate colds.  I’m not crazy about February.  Here in western Oregon, February is grey and miserable.  Rainy, grey and miserable.

My head feels like…  Well, think of it this way.  Take a balloon, one of those big stretchy ones.  Fill it with not-quite-set-up Jello.  Shove a bunch of whole pecans into it (they look like little brain pieces), and then shake vigorously, so it will feel like there is something kind of solid in it, but not really.  Then draw my face on the balloon.

Yep, that’s pretty much what my head feels like right now.

In honor of cold season, I invite all my readers to reply with how your head feels like when you have a cold.  It’s February.  We could all use a snicker or two.

In the mean time, GO WASH YOUR HANDS!

Image source: Syamak Moattari, School of Public Health Blog Site