Stories tagged influenza A/H1N1

73 countries, more than 25,000 people infected with H1N1.

That's right, Trinidad and Tobago, Dominica, the Cayman Islands, and the United Arab Emirates have all joined the club of countries with reported H1N1, or swine flu, cases. (It used to be such a cool club, but then Germany joined, and... yawn.)

And yet I've stopped thinking about the pandemic. I just have all these DVDs that need my attention.

May
31
2009

Vaccine production
Vaccine productionCourtesy AJC1

US pays billion dollars for developing new flu vaccine

The latest information from Pandemicflu.gov explains the next steps toward an H1N1 influenza vaccine.

BARDA

The Biomedical Advanced Research and Development Authority (BARDA), which is part of the Dept. on HHS, has an official "fact sheet" explaining 2009 H1N1 Vaccine Development Activities.

U.S. Department of Health & Human Services (HHS) Secretary Kathleen Sebelius is directing nearly $1.1 billion in existing preparedness funds to manufacture two important parts of a vaccine for the Strategic National Stockpile, to produce small amounts of potential vaccine for research, and to perform clinical research over the summer. HHS press release

How do vaccines work?

Vaccines work by tricking the immune system into thinking it has been infected with the H1N1 swine flu virus so that it creates antibodies against it. The vaccine is a hybrid of the virus which is similar enough that our immune system will develop antibodies against a specific virus.

How is swine flu vaccine made?

We are now starting step 4.

  1. obtain typical sample of novel H1N1 virus
  2. reproduce sample in eggs
  3. Mix H1N1 and PR8 viruses into eggs and allowing a hybrid strain to be created through a natural re-assortment of their genes
  4. Multiply seed virus into millions of doses
  5. test virus in people to determine the most effective and safest dose to generate a strong immune response to the 2009-H1N1 virus
  6. decide whether to use adjuvants
  7. mass produce vaccine

What is an adjuvant?

An adjuvant is an additive to a vaccine that helps to generate a stronger immune response to the vaccine. When using an adjuvant it is often possible to reduce the size of the vaccine dose and the number of doses needed. Special permission from the Food and Drug Administration will be needed for the adjuvants to be used, as neither one is currently approved for use in this country. Washington Post

Can vaccines be made without using eggs?

"The federal government has given the vaccine industry $1.3 billion to spur a shift from growing the viruses in eggs to growing them in stainless steel tanks containing mammalian cells.

Such cell culture could shave a few weeks off the process, experts estimate, and would eliminate the need for millions of eggs on short notice. Some vaccines made in cells have been approved in Europe but not in the United States." New York Times

Learn more about making swine flu vaccine

How to make a swine flu vaccine BBC
CDC May 28 Press Briefing transcript
Flu vaccine development questions and answers BARDA

May
24
2009

Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.
Antigenic shift in flu viruses: is when at least two different strains of a virus combine to form a new subtype having a mixture of the surface antigens of the two original strains.Courtesy National Institute of Allergy and Infectious Diseases (NIAID)

Model of H1N1 flu virus takes shape

Genetic analysis of the new H1N1 virus shows that the hemagglutinin (the H in H1N1) and two other genes are from the 1918 Spanish flu virus and have been living in pigs ever since. Studies also show that the neuraminidase (the N in H1N1) segment is from the Eurasian swine flu virus that probably leaped from birds to pigs in about 1979.

The new virus differs in 21 of 387 amino acids from the H5N1 virus and the 1918 Spanish flu (also an H1N1 virus). - Singapore’s Agency for Science and Technology Research report in Biology Direct.

Shape shifting viral surface challenges vaccination success

"Viruses isolated from patients during the first two weeks of the current outbreak already have changes on the outer surface on the neuraminidase protein that could interfere with antibodies against the virus or alter the effectiveness of future vaccines. But none of the changes have altered the parts of the protein targeted by antiviral drugs, such as Tamiflu or Relenza." Science News

Learn more
If you click through to the source article in Science News, you will see a great three dimensional model of the influenza A/H1N1 virus with the origin of each of the virus's pieces explained.

May
17
2009

Cold noses are good for preventing bird flu

Don't let your children do this
Don't let your children do thisCourtesy KnOizKi

A recent study may explain why the bird flu has not become a pandemic. The human nose is too cold. Avian flu viruses prefer 104 degree F. The temperature in our noses is usually less than 90 degrees F. Critics of the study point out that it was only done in petri dishes so may not be an accurate reflection of what happens in humans.

Since the bird flu virus re-emerged in 2003, there have been only 423 reported cases. If the viruses manage to get into the lower lung, however, they replicate so quickly that 6 out of 10 victims (258) died.

The normal seasonal flu kills only 1 out of 1000 victims (250,000 to 500,000 people per year world wide).

Figuring the odds of a deadly mutation

Please comment what you think about this logic.

"When more people get the flu, the chances of a deadly mutation increases. Say the chance of a deadly mutation is one in a million. If 10,000 people get sick, the odds are 10,000/1,000,000 or 1/100. If a million people get sick the chance of a deadly mutation is almost a sure thing."

The new H1N1 virus appears to be more contagious

The percentage of contacts who catch the regular variety of flu from an infected person is between 5 and 15 percent, but current estimates for H1N1 being spread range from 22 to 33 per cent (according to WHO). Reuters via Yahoo News

As of May 15, 2009, 34 countries have officially reported 7520 cases of influenza A(H1N1) infection. World Health Organization

An intriguing mutation has been detected

The virus isolated from the second swine flu patient in the Netherlands has an intriguing mutation in a gene called PB2 that could mean that the virus has become better at spreading from person to person, a team of Dutch researchers reported on Friday on ProMED, a monitoring system for disease outbreaks. But they're the first to acknowledge that it could also be a red herring. Science Insider

You can make a difference

If you can behave in ways that prevent you from catching or spreading this new type of H1N1 flu, you will minimize the odds its changing into a more deadly form.

May
03
2009

Pigs get flu from humans
Pigs get flu from humansCourtesy teresia

Canadian human infects pigs with "swine flu"

"A worker at (a Canadian) farm had traveled to Mexico, fallen ill there and unknowingly brought the disease back to Canada last month. The worker has recovered.

About 10 percent of the 2,200 pigs on the farm got sick. According to the Canadian Food Inspection Agency, all recovered without treatment in five days.

The entire herd remains under quarantine as a precaution. New York Times"

Learn more
For additional information read this Wall Street Journal post titled,
Pigs in Canada Contract Flu Virus