Thursday, December 9, 2004

NEJM -- The Genetic Archaeology of Influenza

NEJM -- The Genetic Archaeology of Influenza:

" "Different strains of influenzavirus have different pathologic effects. For example, infection by the so-called Spanish influenzavirus caused more than 20 million deaths in 1918 and 1919, many of which were due to hemorrhagic pneumonia. To identify the critical components of this virus, mouse-adapted influenza A viruses (Panel A) were modified by Kobasa et al. so that these viruses expressed the form of hemagglutinin encoded by the gene of the 1918 Spanish influenza strain (HAsp), alone (Panel C) or in combination (Panel B) with the form of neuraminidase encoded by the gene of the 1918 Spanish influenza strain (NAsp). They concluded that the HAsp protein is critical to the enhanced cytokine production, inflammation, and hemorrhagic pneumonia that characterized this virulent influenza." "

" "This new study has important clinical and epidemiologic implications. Assuming that the mouse model at least partially reflects the important factors in the virulence of influenza in humans, further dissection of the HAsp molecule is warranted to help identify the critical structural motifs that confer enhanced virulence. This can be accomplished by performing site-directed mutational analyses of the HAsp gene and investigating the effects of these mutations on infection in the mouse model. The identification of these motifs may provide a new epidemiologic tool for surveillance of circulating animal and human influenzaviruses that could be used to predict the emergence of a new, highly virulent pandemic strain. In addition, these detailed molecular studies could facilitate the identification of antigenic epitopes to include in vaccines in order to protect people against related pandemic strains." "

The above comments are in reference to a recent article in Nature titled Enhanced virulence of influenza A viruses with the haemagglutinin of the 1918 pandemic virus. This is exciting and excellent work which opens the way for more fundamental basic science animal research as well as clinical studies.

Friday, December 3, 2004

Pennsylvania Has Its First Influenza Case

Type A-Fujian influenza has been confirmed in a Philadelphia resident, the first laboratory-confirmed case of influenza in Pennsylvania. Of note, this strain was included in the vaccine.

Saturday, November 27, 2004

Bird Flu Pandemic inevitable, 7 million people could die, WHO

Bird Flu Pandemic inevitable, 7 million people could die, WHO:

""The World Health Organization is urging countries to prepare for an ‘inevitable flu pandemic' it believes will probably come from a mutated bird flu virus. Dr Klaus Stohr, WHO Influenza Program Coordinator, says as many as seven million people could be killed.

Stohr is urging health ministries in Asian countries to prepare and take measures for a probable flu pandemic. Dr Stohr insists it is only a matter of time - we have gone beyond wondering whether there will be one, the stage now is trying to forecast ‘when' a pandemic will hit.

Dr Stohr says the next pandemic will most likely come from a mutation of the bird (avian) flu virus. He said "Even with the best-case scenarios, the most optimistic scenarios, the pandemic will cause a public health emergency. There are estimates which would put the number of deaths in the range of between two and seven million."

The H5N1 bird flu strain, the most dangerous, has hit Thailand and Vietnam hard. Millions of poultry have had to be destroyed - 30 people have died.

The virus only kills humans who have close contact with infected poultry. The concern among health experts is that the virus could mutate and spread from human to human. If the virus were to infect a pig, the jump (mutation) from pig to human would be much more likely (emphasis mine).

If the strain were to mutate and have the ability to spread among humans, nobody would be immune - the consequences could be catastrophic. According to Stohr, this could happen at any time.

WHO experts say that countries in Asia which have the weakest health systems are precisely the ones that need the most support as they are the most likely places to host the beginnings of a pandemic. ""

That bolded phrase--The concern among health experts is that the virus could mutate and spread from human to human. If the virus were to infect a pig, the jump (mutation) from pig to human would be much more likely--deserves further explanation. I'm reading the book The Great Influenza, by John M. Barry, who gives a nice summary of why pigs can make it fly (so to speak):

""The virus may also adapt indirectly, through an intermediary. Some virologists theorize that pigs provide a perfect "mixing bowl", because the sialic-acid receptors on their cells can bind to both bird and human viruses. Whenever an avian virus infects swine at the same time at the same time that a human virus does, reassortment of the two viruses can occur. An an entirely new virus can emerge that can infect man. In 1918 veterinarians noted oubreaks of influenza in pigs and other mammals, and pigs to day still get influenza from direct descendents of the 1918 virus. But it is not clear whether pigs caught the disease form man or man caught it from pigs.""

For more information, see The World Health Organization page on pandemic preparedness.

Friday, November 26, 2004

Making The Flu Vaccine Go Further

NEJM: Dose Sparing with Intradermal Injection of Influenza Vaccine (free full text)

NEJM: Serum Antibody Responses after Intradermal Vaccination against Influenza (free full text)

Wednesday, November 17, 2004

Do you have the flu, or something else?

Many people complain they're down with the 'flu' without really knowing whether it's influenza or not. While browsing my new Google ad sense banner (see left lower gutter) , I found a link to QuickVue, a test for influenza which I never knew existed (or had forgotten existed). It uses a nasal swab (and obtaining a sample is therefore less noxious than getting a Rapidstrep test) and takes about ten minutes to give a result. I have no information on cost.

Thursday, November 11, 2004

Flu Vaccine Shortage A Blessing In Disguise?

The flu vaccine shortage of 2004 has focused national (if not world) attention on how we produce influenza vaccines, which companies produce them, and how vulnerable our present system is to interuptions. We haven't seen a major flu pandemic like those of 1918 or 1957 or 1968 yet. It's quite possible that changes to the system that result from the current shortage will make us more prepared for the next pandemic, whenever it comes. We may be seeing the early stages of it in Thailand and Vietnam in the form of bird flu....

Weathering the Influenza Vaccine Crisis

NEJM: Weathering the Influenza Vaccine Crisis

""Influenza vaccine is especially vulnerable to interruptions in supply, because of the unique features of influenza-vaccine production. Unlike any other vaccine, influenza vaccine must be reformulated to keep pace with antigenic changes in the hemagglutinin and neuraminidase proteins of influenzaviruses — essentially necessitating the manufacture of a brand new product from scratch every year. The process is a long one, beginning with the identification of new antigenic variants in the autumn of the previous year and the selection of the strains for inclusion in the vaccine, and proceeding to the generation of appropriate reference reagents, the production and purification of the vaccine antigens, and packaging and distribution, all within a period of six to eight months.""

Thursday, November 4, 2004

Changing Shot Technique May Extend Flu Vaccine (Los Angeles Times)

Changing Shot Technique May Extend Flu Vaccine (Los Angeles Times):

""Los Angeles Times - Supplies of the influenza vaccine could be expanded by up to five times by changing how the shot is given — administering a small dose under the skin rather than a larger dose into muscle, two teams of researchers reported Wednesday.""

[Via Yahoo! News: Top Stories]

Sunday, October 31, 2004

WHO Calls Summit to Address Flu Pandemic

WHO Calls Summit to Address Flu Pandemic:

""The World Health Organization has called an unprecedented summit meeting next week of flu vaccine makers and nations to expand plans for dealing with the growing threat of a flu pandemic.Sixteen vaccine companies and health officials from the United States and other large countries already have agreed to attend the summit in Geneva, Switzerland, on Nov. 11, said Klaus Stohr, influenza chief of the United Nations' health agency.With increasing signs that bird flu is becoming established in Asia and several worrisome human cases that can't be linked directly to exposure to infected poultry, it's only a matter of time until such a virus adapts itself to spread more easily from person to person and cause a severe worldwide outbreak, he said.""

[Via My Way News]

Monday, October 25, 2004

CDC: What Everyone Should Know About Flu and the Flu Vaccine

CDC: What Everyone Should Know About Flu and the Flu Vaccine

New Interim Guidelines Address Use of Antiviral Medications for Influenza

Influenza Antiviral Medications: 2004-05 Interim Chemoprophylaxis and Treatment Guidelines

""Influenza antiviral medications are an important adjunct to influenza vaccine in the prevention and treatment of influenza. In the setting of the current vaccine shortage, CDC has developed interim recommendations on the use of antiviral medications for the 2004-05 influenza season. These interim recommendations are provided, in conjunction with previously issued recommendations on use of vaccine, to reduce the impact of influenza on persons at high risk for developing severe complications secondary to infection.""

[Via Medscape Headlines]

How To Reduce The Risk Of Catching The Flu

From the JCAHO:

New National Campaign Offers Americans Three Easy Steps To Prevent Infections

The Joint Commission urges Americans to do three easy things to limit the spread of respiratory infections in health care settings and communities.

  • Clean your hands – Rub hands vigorously with soap and warm water for at least 15 seconds after using the bathroom, taking out the trash, changing a diaper, or before handling food. Use of alcohol-based hand sanitizers is an acceptable alternative. Americans should also not hesitate to ask their doctors, nurses, dentists or other caregivers whether they have cleaned their hands before rendering care. It is also important that your hands be clean when caring for a sick friend or family member at home.
  • Cover your mouth and nose – To stop the spread of infectious diseases through sneezes and coughs, cover your mouth and nose with a tissue, your hands, or the crook of your elbow. Then, remember to wash your hands.
  • Avoid close contact – A fever or symptoms of a contagious illness are clear signs to you or your child to stay at home and away from other people, either at work or at school. If you are sick and go to work or school, you place others at risk for getting sick as well.

Sunday, October 17, 2004

Coping Strategy For Lack Of Flu Vaccinations

In discussing the issue of influenza vaccinations with your doctor, you should be aware that there are ways to treat the flu once you get it. One drug is called Tamiflu (oseltamivir phosphate). Relenza (Zanamivir) is another. Tamiflu comes in capsule and oral suspension form whereas Relenza is inhaled via 'diskhaler'. These drugs interfere with the ability of Influenza A and B to aggregate and be released from cells. Both are 'designer drugs' in that their molecular structures were created in the lab specifically for their anti-neuraminidase activity:

""What is Tamiflu used for?

Tamiflu is for treating adults, adolescents, and pediatric patients 1year of age and older with the flu whose flu symptoms started within the last day or two. Tamiflu is also used to reduce the chance of getting the flu in people age 13 and older who have a higher chance of getting the flu because they spend time with someone who has the flu. Tamiflu can also reduce the chance of getting the flu if there is a flu outbreak in the community." "


Though clearly not a substitute for flu shots, their lack of availability makes having a 'Plan B' necessary. If history is any guide, Tamiflu and Relenza will become commodity drugs just like ciprofloxacin was after the Anthrax scare.

Rush Limbaugh Is Playing The Blame Game

Michelle Malkin has a quick note on the flu vaccine shortage, and points to a Rush Limbaugh piece: Clintons Ruined Vaccine Industry. Rush basically argues that it's all Hillary's fault because of her role in the Government Vaccine Buying Program. This is a classic case of hindsight bias; the tendency of people with outcome knowledge to exaggerate the extent to which they would have predicted the event beforehand. Yes, I'm sticking up for Hillary here. It IS a powerful example of why the approach taken by the vaccine buying program is flawed. What we should be doing is asking ourselves whether we need to make changes vis-a-vis our other vaccine programs.

The October 14, 2004 Wall Street Journal editorial 'Infectious Politics' (reproduced here) has some disturbing statistics:

  • Hib1 3
  • Influenza 2
  • Hepatitis A 2
  • Hepatitis B 2
  • DTaP2 2
  • Measles, mumps, rubella 1
  • Tetanus 1
  • Tetanus-diphtheria 1
  • Polio 1
  • Chickenpox 1
  • Pneumococcal conjugate (children) 1
  • Pneumococcal polysaccharide (adults) 1
  • Meningococcal 1

and asks the question:

" "Whether or not Chiron disclosed enough about its manufacturing woes is an issue of financial regulation. The main question for public health ought to be how did we arrive at a place where closing a single plant can endanger so many people?" "

Let's stop playing the blame game and figure out how to improve our vaccine production system. To again quote the WSJ piece:

" "There's no shortage of ideas for how to promote greater vaccine production, with many of the best ideas coming from the few manufacturers that remain. Now would be a good time to hear them out. As deadly as the flu is, consider the dangers of such infectious diseases as measles or whooping cough. Those are the next outbreaks to worry about if Washington keeps blaming everyone but itself for the vaccine crisis." "

Lancet: Summary of Flu Vaccine Woes

The Lancet: Vaccine preparedness, or not:

The problem

" "So, what went wrong at Chiron's production plant in Liverpool, UK? On Aug 26, according to Chiron, Serratia marcescens was found in a "small number of lots". The company informed health agencies in the UK and USA, and planned to delay release of the vaccine until early October while it tried to resolve the contamination issue. S marcescens is an important human pathogen because of the growing number of cases of infection by this organism, its virulence, and its increasing resistance to antibiotics. MHRA visited the Liverpool site, and Chiron thought it could address the concerns of the inspectors. The problem, says MHRA, is that the contaminated lots cannot be separated from the whole batch." "

The lesson:

" "There is a lesson here, about vaccine supply. It is not sensible to restrict manufacturing licences, in the case of influenza vaccine and especially in the USA, to two suppliers. At a blow, half this year's stocks were impounded. The risk (of faulty batches) should be spread across several manufacturers." "

December, 2004
Sun Mon Tue Wed Thu Fri Sat
  1 2 3 4
5 6 7 8 9 10 11
12 13 14 15 16 17 18
19 20 21 22 23 24 25
26 27 28 29 30 31  
Nov  Feb

Feeds and Categories

Blog Roll

Google Modules
   Body Mass Index
   Allowable Blood Loss

   The Ether Way
   Westmead Anaesthesia Blog
   Book of Joe
   i'm so sleepy

   Aggravated DocSurg
   Retired Doc
   Finger and Tubes
   Running A Hospital
   Chance To Cut
   DB's Medical Rants
   Palmdoc Chronicles
   The Well-Timed Period


Geeks Like Me
   Seth Dillingham
   Jonathan Greene