Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

[Mingus]

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16779721&query_hl=3&itool=pubmed_docsum

1: J Infect Dis. 2006 Jul 15;194(2):159-67. Epub 2006 Jun 9. Related Articles, Links
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Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets against Homologous and Heterologous Challenge.

Govorkova EA, Webby RJ, Humberd J, Seiler JP, Webster RG.

Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, 38105-2794, USA.

Background. Multiple cases of transmission of avian H5N1 influenza viruses to humans illustrate the urgent need for an efficacious, cross-protective vaccine.Methods. Ferrets were immunized with inactivated whole-virus vaccine produced by reverse genetics with the hemagglutinin (HA) and neuraminidase genes of A/HK/213/03 virus. Ferrets received a single dose of vaccine (7 or 15 mu g of HA) with aluminum hydroxide adjuvant or 2 doses (7 mu g of HA each) without adjuvant and were challenged with 10(6) 50% egg infectious doses of A/HK/213/03, A/HK/156/97, or A/Vietnam/1203/04 virus.Results. One or 2 doses of vaccine induced a protective antibody response to the vaccine strain. All immunization regimens completely protected ferrets from challenge with homologous wild-type A/HK/213/03 virus: no clinical signs of infection were observed, virus replication was significantly reduced (P<.05) and was restricted to the upper respiratory tract, and spread of virus to the brain was prevented. Importantly, all vaccinated ferrets were protected against lethal challenge with the highly pathogenic strain A/Vietnam/1203/04. The 2-dose schedule induced higher levels of antibodies that were cross-reactive to antigenically distinct H5N1 viruses.Conclusions. H5N1 vaccines may stimulate an immune response that is more cross-protective than what might be predicted by in vitro assays and, thus, hold potential for being stockpiled as "initial" pandemic vaccines.

PMID: 16779721 [PubMed - in process]

 

[Mingus]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

Related NewScientist article

http://www.flutrackers.com/forum/showthread.php?p=17353#post17353

 

[AlaskaDenise]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

Are these "cross-reactive" VAX able to be effective long enough?

Back in April, when I first read about them (see posts at http://www.flutrackers.com/forum/showthread.php?t=4350&highlight=cross+reactive+immunity) ...the cross-reactive effect was reported to work for only 2 to 4 weeks. The HK ducks had H9N2 only 2-3 weeks prior to H5N1 exposure (for which they did NOT get the H5N1, but did have antibodies).

I think looks like a good path, however only near-to-exposure VAX may work reliably.

.

 

[Mingus]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

This cross-reaction is "relatedness-related"

The more the strain is similar the more high the cross-reaction will be.

H9N2 is a total other class of hemagglutinin and neuraminidase so the cross-reaction will always be poor.

If we look for cross-reaction for different clades of H5N1 we will talk about something else.

Different clades of H5N1 will always be more similar than comparison with any other H or N sub-class.

 

[Sonny]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

Mingus would you look at this? Could you make one simular to this?
I think the format is very good. The Isolates are compared against the Vaccine strain. The "open boxes (a,b,c,d,e) identify the HA1 antegen sites". I have Microsoft Office premium but havent used it. It's just the HA1 antegen sites but most vaccines only have the HA1 epitoes. eh? If you track the isolate changes of the antigen sites against the latest vaccine strain "indo/5/2005/H5N1", you'll show a "countdown to vaccine failure"?

http://jvi.asm.org/content/vol78/issue15/images/large/zjv0150449440002.jpeg

FIG. 2. Alignment of HA1 amino acid sequences of Mexican lineage isolates with that of the consensus sequence made with 18 early isolates. The underlined residues are potential glycosylation sites, and the residues in the open boxes are previously identified antigenic sites with H1 and H3 molecules. , substitution sites demonstrated in an H5 escape mutant; , amino acid substitution sites in sublineage A and B viruses analyzed in this study. Overlapping sites are circled.

 

[Mingus]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferre

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferre

Yes, It is easy to do this with the freeware BioEdit.

But I never find an antigenic site map as clear as there is available for human virus like H1 and H3.

Most of the antigenic site are located in HA1.

Why do you ask ?


There is one I quickly made from an old H5 alignement not too fresh.
View attachment alignement H5.bmp
The letter indicate different sequence from the quigai strain.
Dot point indicate homology

 

[Sonny]

Re: Immunization with Reverse-Genetics-Produced H5N1 Influenza Vaccine Protects Ferrets a

Link to full article:
http://jvi.asm.org/cgi/content/full/78/15/8372

In a world where viruses are always changing.. Any changes in the antigen sites of the circulating viruses from the vaccine strain (A/Indo?5/2005) would decrease the affinity oh the vaccine antibodies for the virus antigens. 'Countdown to Vaccine Failure"

How else do they figure out it's time for a new vaccine strain?


http://jvi.asm.org/cgi/content/full/78/15/8372