1957 exposure may give H5N1 immunity (?text?)

[tropical]

From FluWIki today, an globeandmail.com news:

http://www.theglobeandmail.com/servlet/story/LAC.20080130.FASS30/TPStory/Environment

...
Geezers and flu
The over-50s may be at less risk during a bird flu pandemic than younger adults and children, according to new research.
Scientists at the National Institute for Infectious Diseases in Rome say that exposure to older flu strains before 1957 may have provided some immunity, The Sunday Telegraph reports. Experts say that the current deadly H5N1 virus is genetically similar to a part of the older virus that caused the 1918 Spanish flu pandemic

(?!?)

, and so people over 50 may have some protection from flu outbreaks that followed.

(?!?)

Bird flu has killed more than 200 people, mainly those in younger middle age and children.
...
___

(?)

[HenryN]

Re: 1957 exposure may give H5N1 immunity (?text?)

From FluWIki today, an globeandmail.com news:

http://www.theglobeandmail.com/servlet/story/LAC.20080130.FASS30/TPStory/Environment

...
Geezers and flu
The over-50s may be at less risk during a bird flu pandemic than younger adults and children, according to new research.
Scientists at the National Institute for Infectious Diseases in Rome say that exposure to older flu strains before 1957 may have provided some immunity, The Sunday Telegraph reports. Experts say that the current deadly H5N1 virus is genetically similar to a part of the older virus that caused the 1918 Spanish flu pandemic

(?!?)

, and so people over 50 may have some protection from flu outbreaks that followed.

(?!?)

Bird flu has killed more than 200 people, mainly those in younger middle age and children.
...
___

(?)

They are refering to the N1 in H1N1.

[tropical]

Re: 1957 exposure may give H5N1 immunity (?text?)

They are refering to the N1 in H1N1.

Thank you for the clarification Dr. Niman.

Maybe I'm wrong, but I thought these cross-protections, like that from:
"... exposure to older flu strains before 1957 may have provided some immunity"
are in the sphera of possibilities only.

[gsgs]

Re: 1957 exposure may give H5N1 immunity (?text?)

but how much is "some" ?

even seasonal vaccine doesn't work so well

NA only contributes about 1/3 compared with HA

seasonal vaccine protection almost expires after 1 year

50 years since 1957

those who lived in 1957 are now old and old people's immunity
reaction becomes bad (see the seasonal vaccine experience)

[HenryN]

Re: 1957 exposure may give H5N1 immunity (?text?)

Thank you for the clarification Dr. Niman.

Maybe I'm wrong, but I thought these cross-protections, like that from:
"... exposure to older flu strains before 1957 may have provided some immunity"
are in the sphera of possibilities only.

There is some experimental evidence for this in animals exposed to H1N1 and then challenged with H5N1, but the protection was minimal.

[Michael Coston]

Re: 1957 exposure may give H5N1 immunity (?text?)

Tropical,

The complete study is available on the CDC's Journal of EID website.

http://www.cdc.gov/eid/content/14/1/121.htm

Volume 14, Number 1?January 2008
Research
Cross-subtype Immunity against Avian Influenza in Persons Recently Vaccinated for Influenza

Cristiana Gioia,* Concetta Castilletti,* Massimo Tempestilli,* Paola Piacentini,* Licia Bordi,* Roberta Chiappini,* Chiara Agrati,* Salvatore Squarcione,* Giuseppe Ippolito,* Vincenzo Puro,* Maria R. Capobianchi,* Comments to Author and Fabrizio Poccia*
*National Institute for Infectious Diseases "Lazzaro Spallanzani," Rome, Italy

Suggested citation for this article

Abstract

Avian influenza virus (H5N1) can be transmitted to humans, resulting in a severe or fatal disease. The aim of this study was to evaluate the immune cross-reactivity between human and avian influenza (H5N1) strains in healthy donors vaccinated for seasonal influenza A (H1N1)/(H3N2). A small frequency of CD4 T cells specific for subtype H5N1 was detected in several persons at baseline, and seasonal vaccine administration enhanced the frequency of such reactive CD4 T cells. We also observed that seasonal vaccination is able to raise neutralizing immunity against influenza (H5N1) in a large number of donors. No correlation between influenza-specific CD4 T cells and humoral responses was observed. N1 may possibly be a target for both cellular and humoral cross-type immunity, but additional experiments are needed to clarify this point. These findings highlight the possibility of boosting cross-type cellular and humoral immunity against highly pathogenic avian influenza A virus subtype H5N1 by seasonal influenza vaccination.




Hope this helps

[tropical]

Re: 1957 exposure may give H5N1 immunity (?text?)

Thank you FLA_Medic, Dr. Niman, and gsgs.

[gsgs]

Re: 1957 exposure may give H5N1 immunity (?text?)

someone with knowledge in immunology please write a summary !



>23.8% had twofold or more increase of CD4 T-cells

>suggests that N1 seems to be the main target for cell-mediated cross-type immunity against
>influenza (H5N1) and influenza (H3N2)/(H1N1) vaccine strains.

the NA in the seasonal vaccine is small (and producers refuse to say, how much is included !)
and it degrades quickly. How fresh was the used vaccine ?

> HI titers against influenza (H5N1) remained at undetectable levels after seasonal vaccination
> (data not shown), but a rise of neutralization titer >20-fold over baseline was observed
> in 13 (34.2%) of 38 donors

> suggests that this type of antibody response was mainly CD4 T-cell independent.

> cross-reactive immunity may involve cellular and/or humoral responses, but the humoral response
> seems to be CD4 independent.

[Isatis]

Re: 1957 exposure may give H5N1 immunity (?text?)

gsgs, old to you is something different than to me I was three years old in 1957 and I'm only 52. That's not old.

I am also mystified by these research findings.
On the one hand, I read that children should get higher doses of flu vaccines to make them work or that boosters are needed (then read this is poppycock). Adjuvants are needed to make vaccines work better they say.

Trying to read between the lines and ask "who does this information benefit?"