Stanford studies explore potency of flu vaccines

Study finds men with high testosterone get less benefit from flu shots; researchers work toward "universal flu vaccine"

Where flu vaccines for men are concerned, with virility comes virulence, according to a new report released by Stanford.

The report states that men with high levels of testosterone circulating in their blood get less benefit from influenza vaccines, according to the report published Dec. 23 in "Proceedings of the National Academy of Sciences."

The report comes at a time when H1N1, also known as swine flu, is sweeping through the United States. Last week, a 41-year-old woman died of the flu strain in Santa Clara County, and a 48-year-old woman with underlying health issues died later in the week. There have been two flu deaths reported in Marin County this week and two more suspected flu deaths in Santa Clara County.

A 2009 outbreak of H1N1 infected between 43 million and 89 million people worldwide and killed between 8,870 and 18,300 during the same year. But that outbreak was dwarfed by a pandemic of swine flu nearly 100 years ago, according to the Centers for Disease Control.

The "Spanish flu" of 1918 killed as many as 50 million people worldwide and infected about 500 million people, about a third of the world's population at the time, the agency stated.

Men with low amounts of testosterone and women get a strong antibody response from a flu shot, but the hormone doesn't appear to interfere with the body's actual immune response, said Mark Davis professor of microbiology and immunology and director of Stanford'sĀ Institute for Immunity, Transplantation and Infection. Instead, it appears that testosterone may interact with certain genes that dampen the body's response to the vaccine, the report states.

Scientists noted years ago that women have a higher immune response to the vaccinations from the flu, measles, mumps and yellow fever, the report states.

"This is the first study to show an explicit correlation between testosterone levels, gene expression and immune responsiveness in humans," said Davis, who is also the Burt and Marion Avery Family Professor of Immunology. "It could be food for thought to all the testosterone-supplement takers out there."

Men are also more susceptible to viral, bacterial, parasitic and fungal infections than women are, according to the study.

The CDC states that flu-related illnesses kill between 3,000 and 49,000 Americans each year. A separate team at Stanford is trying to reduce that number by developing a universal vaccine to influenza.

Flu strains vary from year to year and today's flu vaccines must target specific strains that health officials believe will be particularly deadly or easily spread, a report from the Stanford School of Medicine states. The officials must make "educated guesses" as to which flu to defend against.

The Stanford team wants to use new understanding of the architecture of flu viruses to create a vaccine that works against a broader range of flu strains and can be manufactured more quickly than current vaccines.

Flu viruses are covered with proteins called hemagglutinins, which resemble the head and stem of mushrooms, the report states. Today's vaccines contain inactivated viruses that identify the "head" of the hemaggluttinins to the immune system and teach it to attack the strain of flu with that hemaggluttinin. The immune system then quickly eradicates the flu strain before it makes its host sick, according to the report.

But the "head" of the mushroom varies from year to year and the "stem" remains relatively constantly. Stanford researchers aim to develop a vaccine that identifies flu viruses based on the hemaggluttinin stem rather than its head, which would theoretically make the vaccine more protective against different strains of flu and could even offer universal protection, according to the report.

"This is an important project for world health," said senior author James Swartz said, noting that the vaccine must not only be broadly effective against different strains of flu but cheap to produce so that it can be widely distributed.

"These are big challenges but we are committed to the effort."

Swartz is the James H. Clark Professor in the School of Engineering and professor of chemical engineering and of bioengineering. The lead author was postdoctoral scholar Yuan Lu.


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Posted by Chrisc
a resident of College Terrace
on Jan 9, 2014 at 12:44 pm

Good article. Interesting and understandable. Thanks.
P. S. This is my third try to post due to the submit processing demanding a category. There is no category for this article or comment! Should you have one for science? Or "what's going on at Stanford?"

Like this comment
Posted by Impotent
a resident of Midtown
on Jan 10, 2014 at 9:12 am

It seems that many flu vaccines are useless for the flu viruses they were made to protect against. In spite of getting vaccinated, 3 out of 4 times I get the flu I was vaccinated for anyway!

Like this comment
Posted by CrescentParkAnon.
a resident of Crescent Park
on Jan 10, 2014 at 10:43 am

Does this mean that testosterone beats the flu virus out of a man's system and that the flu vaccine hampers that somewhat? That is, do men with low testosterone get the flu more and worse and the vaccine study just piggybacks on that fact?

Like this comment
Posted by CrescentParkAnon.
a resident of Crescent Park
on Jan 10, 2014 at 10:46 am

Hey Impotent ... how do you know you got the flu? You probably just caught a cold, the flu is a different animal. Most colds and other viruses make you exaggerate that you wish you were dead sometimes, but the flu can really kill you. I think I got the flu for real just once in my life, and it knocked the hell out of me for over a weak. I could hardly move, it was an entirely different experience from whatever I had had before in my life, though I did not verify that with a doctor.

Like this comment
Posted by James
a resident of another community
on Jan 10, 2014 at 11:04 am

It would be so nice if you would kindly include a link to the publication.

Like this comment
Posted by Impotent
a resident of Midtown
on Jan 12, 2014 at 2:18 pm

Np, I had the actual flu, confirmed by the doctor with a "snot sample". Spent ten days in bed each time with very high fever, swollen throat, vomiting ( a cold does not make you vomit, and is over in <5 days). Tamiflu worked for some, but not for the last two.

Like this comment
Posted by Jake
a resident of Green Acres
on Jan 23, 2014 at 11:59 am

Impotent - the flu vaccine does not generally prevent the flu, but it might help reduce symptoms. Its a common misconception. In studies where the flu vaccine is tested against live flu virus, the vaccine prevents infection in 1 out of 33 people. However, in 20 out of 33 people, it runs a milder course. In the remaining third, it does nothing. Thats if the virus is a close or exact match, which isnt always the case. The vaccine is considered 'effective' if you do not require medical care.
But by milder course, you will still get a 103 degree fever, thick mucus cough, and extreme lethargy, but only for 2-3 days as opposed to 7-10 before your body turns the tide. You will still have long lasting damage to your lungs that will take months to heal.
I have had the flu both in years where I was vaccinated and those where I was not, and it was much longer in the year I didnt get the vaccine. I missed an entire week of work, compared to 2 days and a weekend for the time I got h1n1 swine after being vaccinated. Yes it was lab confirmed.

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