Inflammation el pt

Avian Flu and CLL

Date:       November 17, 2024
Updated: July 6, 2024

by Chaya Venkat

A Cave Is No Place to Live

Unless you have been living in a cave, you cannot have missed all the references to "bird flu", "avian flu", "H5N1 super flu" in the mainstream media. Politicians are talking about it, epidemiologists are talking about it, virologists are talking about it, Wall street pundits are talking about it. There are as many opinions about bird flu as there are chickens in China. I would like to add my two cents, but I will stay strictly focused on issues as they pertain to CLL patients. For starters, here are issues that I will not be discussing:

1. Will the present bird flu become a human pandemic? I do not know.
2. When is the bird flu going to become a full-fledged pandemic? Your guess is as good as mine.
3. How many are going to die? Does it matter, whether it is 50 million or 100 million, give or take? Both numbers are too large for me to comprehend.
4. Whose fault is it? What difference does it make? In the final analysis our humanity unites us all.
5. What can we do about it? Ahh. Now you are talking.

This article is about the special risks we face as CLL patients, as immune compromised individuals, and the game plan that we might want to consider in light of that. There are no easy solutions, for us or for anyone else on this planet for that matter, if / when this pandemic becomes a reality. I have no magic bullets to offer, just some commonsense observations in case you have not thought of them yourself. I also attach some up-to-date reference material that you might find handy, a bit more authoritative information than the typical newscast stuff.

I would like to point out one other thing. If you are not a CLL patient yourself but a family member of caregiver, remember your family forms an integral unit; most likely you will all share the same exposure risks. If one of you gets the virus, chances are the rest of your family will too if, as expected, the virus develops high degree of contagiousness. You and your family will have to address this new danger as a single unit, with an agreed upon game plan that protects the whole unit. The weakest link determines the strength of the chain.

Why Is Avian Flu More of a Risk for CLL Patients?

• There is evidence that infection of human lung cells with the H5N1 avian influenza virus leads to intense inflammation and deep-seated viral pneumonia.
• The viral pneumonia seems to be followed more often than not by opportunistic bacterial pneumonia. Patients who survive the initial viral pneumonia then have to contend with the bacterial pneumonia. It goes with the territory that CLL patients whose immune systems are compromised to begin with, are less likely to resist the initial flu infection, and more likely to get opportunistic infections as a second punch. We are also less able to fight off pathogens when we do get infected. In addition, many CLL patients have existing pulmonary co-morbidities such as bronchitis, sinusitis, COPD, asthma, etc.
• Over and beyond the immune compromised status of CLL patients in general, those that have undergone recent immune suppressive therapies are obviously more at risk. For example, chemotherapy drugs such as fludarabine and the monoclonal antibody Campath lead to deep and long term reductions in T-cell counts. T-cells are at the front line of our immune protection against a whole host of pathogens, and people with decreased T-cell counts are much more at risk. Other drugs such as steroids (prednisone, dexamethasone) are immune suppressive across the board, reducing counts of all vital immune system cell lines. If the timing of your next round of immune suppressive therapy is in your control, it becomes an exquisite torture trying to out-guess the timing of the avian flu. Therapy choices become a whole lot more complicated if you have to figure a pandemic flu into the equation.
• Autopsies of H5N1 avian flu victims in Asia have revealed lungs choked with debris from the excessive inflammation triggered by the virus. More often than not, major lung damage seems to be done by an over-the-top and excessive immune response rather than the proliferation of the actual virus itself. May I remind you folks one more time, pneumonia and lung infections are the major cause of hospitalization and death in CLL patients (Role of Pulmonary Inflammation in CLL; CLL, Chronic Inflammation and What You Can Do about It). This very bad bug may be hitting us at one of our most vulnerable points.
• As you read more about H5N1 type avian influenza, you will come across the phrase "cytokine storm". This evocative phrase refers to the triggering of a flood of immune system signaling molecules ("cytokines"), raising the alarm about an intruder and calling in all the fighting troops to man the barricades. Problem is, the response is way out of proportion. This is not a case of well thought out and well orchestrated immune response by disciplined troops. The scenario is more like Keystone cops milling around, shooting in all directions, killing friend and foe alike. Lung cells die in droves under this withering attack by the body’s own immune system cells — a case of devastating "friendly fire". By the way, this inability to distinguish between "self" and "non-self" is at the heart of all autoimmune disease. By now you should know that CLL patients are prone to a variety of autoimmune diseases, where the out-of-control immune system attacks red blood cells (AIHA — autoimmune hemolytic anemia), platelets (ITP — autoimmune thrombocytopenia), psoriasis (skin cells), pancreatic islet cells (diabetes), cells lining the GI tract (Crohn’s disease, ulcerative colitis) and the list goes on. This is one more area of vulnerability we have that is targeted by H5N1 virus.
• With the possible (but not totally confirmed) exception of the antiviral Tamiflu, there are not a whole lot of effective drugs out there that can protect against avian flu. There is a lot more about Tamiflu in the later sections of this article.
• Human beings do not have any built-in resistance to this particular virus at this point. That is what makes it such a dangerous thing for us as a species. We have never "met" this particular virus before, our bodies do not know how to handle it. None of us have immune system "memory" to protect us, such as specific immunoglobulins to fight off the first attack.
• Health officials and virologists are hoping that we will be able to develop effective vaccines in a few months after the pandemic starts, and that massive vaccination programs will eventually protect our populations against the ravages of avian flu. This is no small task, and it may take a lot longer than we hope.
• But wait a minute. Have we not been reading that CLL patients do not respond so well with vaccinations, that we do not mount enough of an immune response for the vaccination to "take"? You are absolutely right. Even the annual flu shot or garden variety pneumonia shot are a whole lot less effective in the case of CLL patients (Flu Preparedness). In other words, the much hoped for deliverance from pandemic flu by vaccination is not likely to work very well for us. Bummer!! Indeed.

Prevention, Prevention and More Prevention

If the pandemic flu does become reality, your best bet is probably going to be avoiding the H5N1 viral infection in the first place. In any serious confrontation you may have with this virus, no hard feelings mate but I think the smart money is likely to be on the side of the virus. Prudence is definitely the better part of valor in this situation. There are some rather obvious things to do, in your efforts to say no-thanks to this infection.

• Practice scrupulous personal hygiene, to the tune of getting ever so slightly paranoid about it. Wash your hands thoroughly with soap and hot water a dozen times or more each day. And none of the cursory two second wash / rinse off either. All of us have watched doctor shows on TV, you have seen how the guys in white coats scrub up prior to a big operation. Just pretend you fulfilled your mother’s fondest dreams, you are truly "my son the doctor", prepping for major surgery to save yet another life. See if you can get your whole family to follow your lead on this simple and yet very effective prevention technique. Remember, your unit’s risk factor is going to be determined by your least careful member.
• Make a habit of carrying a bottle of alcohol based sanitizing solution (Purell is a commonly available brand name that seems to do the job but a generic or store brand might do as well) in your purse of pocket. Keep some in the car glove box. Make your kids take some with them in their backpacks. Heck, hang a bottle on the collar of the family pooch. Last but not least, use the stuff every chance you get! You can even get scented and moisturizing varieties, I am told. Most virus infections are picked up by our hands, then carried to our lips, eyes or nose.
• Stay away from gatherings where there are going to be a lot of people. That means sports events, concerts, movie houses, etc. I understand the flu virus can survive outside the host, on hand rests, door knobs, elevator buttons, computer keyboards, public transportation, doctor’s offices and the like for periods ranging from several days to several weeks. It survives longer under cold and moist conditions, which is why the flu season is typically over the winter months.
• In this holiday season, it is going to be hard to avoid family gatherings. But even then, you can practice some degree of social distancing (guys, must you hug and kiss all the ladies?), especially when it comes to the adorable germ-magnet toddlers. You can always buy yourself back into their good graces later on.
• If push comes to shove, learn to make a fashion statement out of N95 face masks and protective gloves. In case you have not heard, the "N95" masks are the ones that are thought to provide some (but not perfect) protection against infection. Plain old cloth or paper masks are of little use. Remember, wash your hands early and often, and break that habit of touching your face, especially the mouth, nose or eyes. Having on a mask might help in breaking that habit. If you wear contact lenses, you might want to consider switching to regular glasses. Not as good as protective and well sealing goggles, but they might catch the odd virus laden micro-droplet aimed at your eye.
• In many Asian societies, politeness dictates that you take your shoes off before coming into the house. It makes sense in this context: why would you want to track any nasty stuff you may have stepped on into your home? Try to leave behind "outside" footwear in the car or garage, and step into "inside" shoes or slippers as you come into the house. I realize it is a little hard to do during the winter months, and even harder to train the dog to wear shoes as you take him out to do his duty. Kidding aside, under worst case scenarios I am not sure what one can do with our beloved pets, their feet and noses seem to go everywhere, and they follow that up with loving licks.
• You can take these precautions and "self-quarantine" to any level that you feel appropriate, dictated by your lifestyle preferences, housing arrangements, level of concern and financial situation. There are a lot of survivalist type websites that you can visit to get a handle on storing sufficient food, water and other essentials to survive for months without having to depend on the outside world. These sites also discuss issues such as breakdown of municipal services (water, electricity, natural gas or home heating oil deliveries, police, paramedical services, etc.). I am not going to second guess these experts. Some of these websites (such as the CDC, Red Cross, WHO) are quite informative and credible. Just be aware an aluminum foil hat may be considered proper attire when visiting some of the more extreme sites. Some of them are holdovers from the days of Y2K hysteria. If you are a conspiracy buff, this is your chance to have some fun, knock yourself silly. There are enough theories out there to satisfy all aficionados.

Medications

The consensus seems to be that Tamiflu (generic name "oseltamivir") is the only anti-viral that may have a chance of controlling the H5N1 virus. Relenza, another antiviral drug on the market, seems to be less popular, probably because it is not effective via oral route but needs to be inhaled. Cheaper and older drugs such as Amantadine are likely to be less effective since the virus may have developed resistance to these drugs due to excessive use in poultry farming in China and elsewhere. Tamiflu is not a vaccine. It is an anti-viral medication that interferes with the ability of the virus to multiply in your body. It is called a "neuraminidase inhibitor". Don’t get confused if you see that bit of jargon in some of the articles I list below.

• Tamiflu was originally developed to treat the common flu. It is hard to get hold of today because supplies and production capacity are limited and governments are stockpiling it. This prescription drug has been in short supply since the news about bird flu broke. Most GPs are reluctant to write prescriptions for it for "normal" people. But as an accredited and card-carrying member of the CLL community, you may have an effective argument why you should be an exception. Tamiflu works best when taken immediately after onset of symptoms (fever, cough, respiratory distress are the common symptoms), no later than 48 hours. In my opinion, even 48 hours is too long to wait for immune compromised folks. You should try to target the first day after onset of symptoms. Seems to me you have a good case for wanting to have a pack of Tamiflu on hand, so that you can begin treatment promptly. The logistics of getting to see the doctor after you develop symptoms, get a prescription, fill it at the pharmacy and start the therapy are likely to be too complex if not impossible in a pandemic situation. See how that argument flies with your healthcare provider. It is not a cheap drug, a 10 pill pack may set you back $100 or more, so do check with your insurance carrier if money is an issue.
• The flip side of the coin, Tamiflu protects you only during the time you are on it. As soon as you quit taking it, you are back to square one. In other words, beware of pulling the plug too soon, you may find yourself having blown your precious stash of Tamiflu on a false alarm and have none left for when the real deal happens. Decisions, decisions. It does not get any easier I am afraid.
• Resist the temptation to buy Tamiflu from the guy selling it from the back of his pickup truck, or the less reputable internet sites. This drug has become a precious commodity, and there are sharks out there willing to sell counterfeit capsules for a hefty fee. If at all possible, depend on your neighborhood pharmacy or reputable drug store.
• That reminds me of another point. Fever is supposed to be one of the major symptoms. But a lot of CLL patients seem to have unusually low "normal" temperatures. So how can you tell when you have a fever? It might make sense for you to develop a chart of your temperature as it waxes and wanes over a day (diurnal rhythms mean our body temperature changes over the hours of the day and night), so that you are better able to tell when your body departs from its "normal" temperature.
• When it comes to annual flu shots, our GP felt that it was important that not only my husband PC should get the shot (he is the one with CLL), but that I get it too. That makes sense. If I got sick chances are excellent that he would catch it too. See if this argument will get you Tamiflu prescriptions for your whole family. Is this a case of "hoarding" or simply being intelligent and prepared? Given our vulnerabilities, I can give you my opinion — but you will have to cross that bridge on your own steam, as seems appropriate to you.
• Let me throw another monkey wrench into this Tamiflu equation. Several researchers say the standard course of 2 capsules of Tamiflu per day for 5 days is not good enough for immune compromised people. They recommend double the dose and for twice as long, to get reasonable level of protection. I suppose that depends on our definition of "reasonable". Beggars cannot be choosers, and in an era of acute shortage of this precious drug, it may simply not be possible to get 4 packs of Tamiflu for your use when and if you get infected.
• Turning our attention to other medications, most of the CLL patients I know depend on several maintenance medications. These could be orally taken CLL drugs such as chlorambucil, prednisone, oral fludarabine, self-injectable Campath, Neupogen, etc. Daily prescription drugs that you may be using include Famvir (anti-viral drug for controlling Herpes virus, shingles), anti-asthmatics such as Singulair, cholesterol lowering statin drugs such as Zocor — the list goes on and on. Do you have a sufficient supply of these medications on hand, so that even if there is not-so-brief interruption in the supply situation you can ride it out? Check your stocks, see if you can get 3-month prescriptions rather than the usual monthly type. Many prescription plans have a mail-order option, where you can get your prescriptions filled for 3 months at a time. While you are about it, make sure you also have enough of the over-the-counter drugs or supplements that you use regularly (fish oil, EGCG, vitamin D3 and low-dose aspirin suggest themselves to me, but you should make up your own list).
• Since opportunistic bacterial infections are going to be a major part of the follow-on risk, and as immune compromised patients we are more at risk than the normal population, it makes sense to talk to you doctor about getting a prescription for broad spectrum antibiotic, one that he considers appropriate for bacterial pneumonia. Incidentally, some physicians are on record that antibiotic therapy should be started as prophylaxis (fancy word that means do it ahead of time, to prevent the infection before it gets a chance to get you). If your GP or oncologist has written similar prescriptions in the past before you went in for routine dental work just to be on the safe side, you should have no trouble convincing him to do it in this instance as well. You may want to make sure the expiration dates on all your prescription drugs is a good long time into the future. Talk to your pharmacist about it if necessary.
• Researchers have suggested that the reason why fit and young folks are also at risk during a flu pandemic is because they have robust immune systems that go even more violently berserk when infected by H5N1. The ensuing "cytokine storm" is the real killer. Based on this and my intuition, I would not recommend indulging in various potions and herbal remedies that are supposed to help build up your immune system. You may end up exacerbating an already out-of-control immune reaction by doing this. Frankly, there is so much hype and snake oil out there right now, I would not trust any of it unless it comes with solid research credentials in peer reviewed journals. Wishful thinking based on glowing anecdotal "testimonials" is going to cost you dearly, I am afraid.

What about Vaccinations?

Right now, no proven vaccine exists that protects people against H5N1 version of Avian Flu. Scientists and healthcare officials are hoping that once the virus has shown its true colors and broken out as a full-fledged pandemic, we will be able to come up quickly with the right vaccine to match it, manufacture it in record time and in sufficient quantities and get it out to the frontlines. I know, this is a very tall order, which is why a lot of folks who study pandemics are losing sleep over it. But eventually we will have a vaccine, it will work, and it will be manufactured, life will go on. Vaccination is the game plan, a way to protect the people who have managed to dodge the bullet that long and had not yet become infected. (In the case of those who became infected, there are only two outcomes: they died, or they survived and therefore developed immunity against the virus. In either case, they are no longer part of the population that needs to be protected by vaccination).

That raises an interesting question for us. As we discussed earlier, vaccinations do not work very well for CLL patients. Vaccinations depend upon the body mounting a sufficient response against the offending pathogen, and then remembering that response so that the next time it sees the pathogen it knows what to do. Part of the immune response depends on very specific immunoglobulins (Igs, for short). Igs are made by plasma cells, which in turn come from healthy B-cells as they mature. Well, there you have it, in a nutshell. CLL patients have plenty of B-cells, in fact way too many of them. But they are not healthy B-cells, they are stunted and deformed CLL B-cells. They do not mature to make good and helpful plasma cells which then become the factories for generating immunoglobulins directed against dangerous pathogens. That is why so many CLL patients suffer from low immunoglobulin levels, get frequent infections and need intravenous infusions of Igs to help them out (IVIg Benefits). Declining Ig levels are a common theme as the years go by after diagnosis if CLL, as the original plasma cells die off and are not replace by new ones.

In addition to not having sufficient levels of Igs and the inability to produce the right type of Igs when exposed to vaccinations, CLL patients also have poorly functioning T-cells, dendritic cells and other cell lines that all play an important role in directing the traffic, mounting an appropriate response to vaccinations. Loss of "memory" cells means our bodies become less able to remember pathogens we may have encountered in the past, or been vaccinated against, and therefore less able to mount a good defense the next time we see the same villain. Many of the chemotherapy drugs that are an unavoidable part of the CLL scene are also very effective at further depleting our immune system reserves.

So, what are our options? Surely we cannot count on becoming Howard Hughes type recluses all our lives. The answer lies in something called "herd immunization". If you are a lone un-vaccinated CLL patient surrounded by a sea of "normal" people who have all been appropriately vaccinated, chances are slim that you will come in contact with the virus. Your protection rests on the immune capabilities of those around you. In other words, as soon as a vaccine becomes available, you should make every effort to get your family vaccinated. You can try your luck with the vaccination shot as well, if your doctor agrees, and you may wish to discuss with him the usefulness of combining the vaccine shot with adjuvants such as cimetidine or ranitidine, along the lines discussed in an earlier article (Flu Preparedness). Well down the road, when the H5N1 flu pandemic is no more than a nasty memory in the general population, and everyone (except you) have developed healthy doses of protection against this particular pathogen in their bodies, you can hope to get IVIG therapy whereby you can "borrow" the immunity developed by your fellow citizens.

In Conclusion

If I have been a little too flip and if my particular brand of humor did not go over too well, I would not blame you. This is a serious subject; perhaps too serious and that is my excuse for trying to lighten it up with lame humor. Do I believe there is significant risk here? I am afraid I do. If not this year, then perhaps in the next few years it will be a real threat. But once again, the name of the game is to play the cards we are dealt to best advantage. Bitching and moaning does not get us anywhere. Getting panicked is even worse since it makes us do stupid things. Smart planning (and action) ahead of time may get us better odds. That is the whole point of this article, I wanted to try and spell out a few action items that you can consider, and implement if they make sense to you. A lot of very smart and well trained experts are looking at this threat. I have no crystal ball that can help me see the future more clearly.

1. Read up on the subject. If dense medical jargon is not your gig, there are enough layperson reports out there to browse. Google gets you millions of hits if you type "bird flu" into the search box.
2. Learn as much as you can about the symptoms, risk factors, ways of preventing infection.
3. Think how all this applies to you, your family, your individual situation. Only you can customize the risk factors and options to match your family and work situations, where you live, your life.
4. Plan: work out your game plan, the one that makes most sense to you and your family. Remember, you need to get buy-in from all the members of your family for the plan to have a good chance of working.
5. Implement. Plans are no good if they stay on the drawing board but go no further. Perhaps FEMA had terrific plans in place to handle hurricanes in the Gulf coast. Too bad no one thought to put the plans into practice, not enough to make a difference.
6. After you have done your best, sit back, relax, and permit yourself to know you have done your best for yourself and your family. We all need to learn how to handle guilt better.

References

Mid-Peninsula Citizen’s Preparedness Committee

This is a link to a comprehensive 68-page PDF document made available by a regional citizens' group in California. It has much useful information and practical preparation guidance for the individual citizen. This work was sponsored and supported by Jane and Peter Carpenter, who have also been strong supporters of CLL Topics since its inception (Peter is a former director of our corporation). This Citizen's Guide, dated July 1, 2024, is highly recommended reading. You might want to check if a more current version has been posted on the Flu Wiki website.

Influenza Pandemic Preparation and Response: A Citizen's Guide

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CIDRAP (Center for Infectious Disease Research and Policy)

This is a link to the CIDRAP website, you may wish to read their well written article on "cytokine storm", as well as browse the website for additional information. This site is a good way to get a good (and current) officially sanctioned overview.

CIDRAP Avian Flu Pages

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NEJM Article - H5N1 in Humans

If you are going to read just one paper on H5N1 flu in humans, this is probably a good choice. As they say, know the face of your enemy before you go into a fight. This article does just that.

Avian Influenza A (H5N1) Infection in Humans (Full-text PDF Article)

N Engl J Med. 2024 Sep 29;353(13):1374-85.

Avian influenza A (H5N1) infection in humans.

Beigel JH, Farrar J, Han AM, Hayden FG, Hyer R, de Jong MD, Lochindarat S, Nguyen TK, Nguyen TH, Tran TH, Nicoll A, Touch S, Yuen KY; Writing Committee of the World Health Organization (WHO) Consultation on Human Influenza A/H5.

National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD

PMID: 16192482
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NEJM Article 2 - Tamiflu

This is a slightly older article, 1999 vintage, but it has a lot of interesting details and you can get the full text by clicking on the link below.

NEJM Tamiflu Article (Full-text Article)

N Engl J Med. 1999 Oct 28;341(18):1336-43.

Use of the selective oral neuraminidase inhibitor oseltamivir to prevent influenza.

Hayden FG, Atmar RL, Schilling M, Johnson C, Poretz D, Paar D, Huson L, Ward P, Mills RG.

Department of Medicine, University of Virginia, Charlottesville, VA

BACKGROUND: Safe and effective antiviral agents are needed to prevent infection with influenza A and B virus. Oseltamivir (Tamiflu) (GS4104), which can be administered orally, is the prodrug of GS4071, a potent and selective inhibitor of influenzavirus neuraminidases. We studied the use of oseltamivir for long-term prophylaxis against influenza in two placebo-controlled, double-blind trials at different U.S. sites during the winter of 1997-1998.
METHODS: We randomly assigned 1559 healthy, nonimmunized adults 18 to 65 years old to receive either oral oseltamivir (75 mg given once or twice daily, for a total daily dose of 75 or 150 mg) or placebo for six weeks during a peak period of local influenzavirus activity. The primary end point with respect to efficacy was laboratory-confirmed influenza-like illness (defined as a temperature of at least 37.2 degrees C accompanied by at least one respiratory and at least one systemic symptom).
RESULTS: In the two studies combined, the risk of influenza among subjects assigned to either once-daily or twice-daily oseltamivir (1.2 percent and 1.3 percent, respectively) was lower than that among subjects assigned to placebo (4.8 percent; P<0.001 and P=0.001 for the comparison with once-daily and twice-daily oseltamivir, respectively). The protective efficacy of oseltamivir in the two active-treatment groups combined was 74 percent (95 percent confidence interval, 53 to 88 percent) at all the sites combined and 82 percent (95 percent confidence interval, 60 to 93 percent) at sites in Virginia, where the rate of influenza infection was higher than the overall rate. For culture-proved influenza, the rate of protective efficacy in the two oseltamivir groups combined was 87 percent (95 percent confidence interval, 65 to 96 percent). The rate of laboratory-confirmed influenza infection was lower with oseltamivir than with placebo (5.3 percent vs. 10.6 percent, P<0.001). Oseltamivir was well tolerated but was associated with a greater frequency of nausea (12.1 percent and 14.6 percent in the once-daily and twice-daily groups, respectively) and vomiting (2.5 percent and 2.7 percent, respectively) than was placebo (nausea, 7.1 percent; vomiting, 0.8 percent). However, the frequency of premature discontinuation of drug or placebo was similar among the three groups (3.1 to 4.0 percent).
CONCLUSIONS: Oseltamivir administered daily for six weeks by the oral route is safe and effective for the prevention of influenza.

PMID: 10536125
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NEJM Article on Tamiflu and other neuraminidase inhibitors

This is a brand new article in the New England Journal of Medicine, full text available free of charge. It discusses Tamiflu and other neuraminidase inhibitors in great detail, in the context of a flu pandemic.

New NEJM Tamiflu Article (Full-text Article)

N Engl J Med. 2024 Sep 29;353(13):1363-73.

Neuraminidase inhibitors for influenza.

Moscona A.

Department of Pediatrics, Weill Medical College of Cornell University, New York, NY

The impact of influenza infection is felt globally each year when the disease develops in approximately 20 percent of the world's population. In the United States, influenza infections occur in epidemics each winter, generally between late December and early March. Recent events, including human cases of avian influenza, have heightened awareness of the threat of a pandemic and have spurred efforts to develop plans for its control.

Although vaccination is the primary strategy for the prevention of influenza, there are a number of likely scenarios for which vaccination is inadequate and effective antiviral agents would be of the utmost importance. During any influenza season, antigenic drift in the virus may occur after formulation of the year's vaccine has taken place, rendering the vaccine less protective, and outbreaks can more easily occur among high-risk populations. In the course of a pandemic, vaccine supplies would be inadequate. Vaccine production by current methods cannot be carried out with the speed required to halt the progress of a new strain of influenza virus; therefore, it is likely that vaccine would not be available for the first wave of spread of virus.1 Antiviral agents thus form an important part of a rational approach to epidemic influenza and are critical to planning for a pandemic.

PMID: 16192481
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Hong Kong Paper on Human Infection by H5N1

A very authoritative and no-nonsense paper from Hong Kong. Let us know if you wish to locate a full text version of this paper. Well written, lots of valuable information that is not out of the reach of the interested layperson reader.

Hong Kong Med J. 2024 Jun;11(3):189-99.

Human infection by avian influenza A H5N1.

Yuen KY, Wong SS.

Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong.

The Southeast Asian outbreak of the highly lethal avian influenza A H5N1 infection in humans is unlikely to abate because of the enormous number of backyard farms providing poultry as the main source of food protein in developing countries. This increases the risk of the emergence of a reassortant pandemic influenza virus with improved human-to-human transmissibility. Currently triage of suspected cases by epidemiological risk factors remains the only practical way of case identification for laboratory investigation and infection control. The clinical usefulness of rapid diagnostic laboratory tests requires more vigorous evaluation. The lethality of this disease may reflect systemic viral dissemination, cytokine storm, or alveolar flooding due to inhibition of cellular sodium channels. The present circulating genotype Z is intrinsically resistant to amantadine and rimantadine. Prognosis may be improved by early treatment with a neuraminidase inhibitor with good systemic drug levels, and post-exposure prophylaxis for health care workers is recommended. The role of immunomodulators and other modalities of therapy requires evaluation in randomised controlled trials, with prospective monitoring of the viral load and cytokine profiles in various clinical specimens. In view of the high fatality of the disease, a combination of contact, droplet, and airborne precautions are recommended as long as resources allow despite the fact that the relative importance of these three modes in nosocomial transmission of avian influenza is still unknown.

PMID: 15951584
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Choices in Handling a Pandemic

This article discusses the issues from the perspective of society having to make choices on how to handle a flu pandemic scenario. Once again, you can get the full article free of charge, just click on the link below.

Netherlands Policy

Neth J Med. 2024 Oct;63(9):339-43.

Use of antiviral agents and other measures in an influenza pandemic.

Groeneveld K, van der Noordaa J.

Health Council of the Netherlands, PO Box 16052, 2500 BB The Hague, the Netherlands.

The Dutch Ministry of Health asked the Health Council for advice on how to prepare for a possible influenza pandemic. In two advisory reports the Committee responsible indicated the measures that it believes would need to be taken if such a pandemic were to reach the Netherlands. During a pandemic, the Committee recommends that every resident of the Netherlands with influenza-like illness should be treated with neuraminidase inhibitors such as antiviral agents. This approach serves to mitigate the course of the disease, to reduce infectivity and to allow patients to build up immunity to the virus. Since up to 30% of the population could become ill, the Committee anticipates that a stock of five million courses of the neuraminidase inhibitor oseltamivir is sufficient. If a pandemic were to occur at a time that the stock does not exceed the present 225,000 courses, the committee advises restricting treatment to three specified groups of patients. If the first few patients are traced shortly after they fall ill, the Committee recommends treatment of the patient and postexposure prophylaxis for his/her close contacts. The Committee does not advocate prophylaxis in general, but it can envisage prophylaxis for particular groups of patients or under particular circumstances. The Committee believes that in order to reduce rapid spread of the virus, schools should be closed and events where large numbers of people gather in a confined space should be cancelled. Because this recommendation would have major social and economic consequences, the Committee understands that its implication will depend on the anticipated severity and extent of the pandemic. The Committee regards vaccination against influenza as the best means of protecting the population. The development of a vaccine should be the absolute priority.

PMID: 16244380
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Cytokine Responses

As the title implies, this article has the scoop on "cytokine storm" that accompanies H5N1 infection. You can get the full text article by clicking on the link, but I must warn you the jargon is a little intimidating in this one.

Cytokine Storm

Respiratory Research 2024 Nov 11;6(1):135 [Epub ahead of print]

Proinflammatory cytokine responses induced by influenza A (H5N1) viruses in primary human alveolar and bronchial epithelial cells.

Chan MC, Cheung CY, Chui WH, Tsao GS, Nicholls JM, Chan YO, Chan RW, Long HT, Poon LL, Guan Y, Peiris JS.

BACKGROUND: Fatal human respiratory disease associated with influenza A subtype H5N1 has been documented in Hong Kong, and more recently in Vietnam, Thailand and Cambodia. We previously demonstrated that patients with H5N1 disease had unusually high serum levels of IP-10 (interferon-gamma-inducible protein-10). Furthermore, when compared with human influenza virus subtype H1N1, the H5N1 viruses in 1997 (A/Hong Kong/483/97) (H5N1/97) were more potent inducers of pro-inflammatory cytokines (e.g. tumor necrosis factor-alpha) and chemokines (e.g. IP-10) from primary human macrophages in vitro, which suggests that cytokines dysregulation may play a role in pathogenesis of H5N1 disease. Since respiratory epithelial cells are the primary target cell for replication of influenza viruses, it is pertinent to investigate the cytokine induction profile of H5N1 viruses in these cells.
METHODS: We used quantitative RT-PCR and ELISA to compare the profile of cytokine and chemokine gene expression induced by H5N1 viruses A/HK/483/97 (H5N1/97), A/Vietnam/1194/04 and A/Vietnam/3046/04 (both H5N1/04) with that of human H1N1 virus in human primary alveolar and bronchial epithelial cells in vitro.
RESULTS: We demonstrated that in comparison to human H1N1 viruses, H5N1/97 and H5N1/04 viruses were more potent inducers of IP-10, interferon beta, RANTES (regulated on activation, normal T cell expressed and secreted) and interleukin 6 (IL-6) in primary human alveolar and bronchial epithelial cells in vitro. Recent H5N1 viruses from Vietnam (H5N1/04) appeared to be even more potent at inducing IP-10 than H5N1/97 virus.
CONCLUSION: The H5N1/97 and H5N1/04 subtype influenza A viruses are more potent inducers of proinflammatory cytokines and chemokines in primary human respiratory epithelial cells than subtype H1N1 virus. We suggest that this hyper-induction of cytokines may be relevant to the pathogenesis of human H5N1 disease.

PMID: 16283933
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Slide Presentations from SUNY Albany

Here are some well-designed and authoritative presentations from the State University of New York at Albany. The first one (you need to scroll down the page), Avian Influenza: the State and Worldwide View is particularly recommended. If you are visually inclined, these slides will help you get the picture.

SUNY Albany slides

Center for Public Health Preparedness, SUNY Albany.

Proceedings of Avian Influenza: Preparation and Response Regional Workshop.

University at Albany School of Public Health, Rensselaer, NY, June 22, 2024.