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Can You Get H1N1 More Than Once?
- Thread starter Legadillo
- Start date
Re: Can You Get H1N1 More Than Once?
The latest study from China indicates that this may have more to do with past vaccinations.
See http://www.flutrackers.com/forum/showthread.php?t=127802
The latest study from China indicates that this may have more to do with past vaccinations.
See http://www.flutrackers.com/forum/showthread.php?t=127802
Re: Can You Get H1N1 More Than Once?
I wonder how prevalent the Spanish Flu was in China in the early 1900's. I don't know how isolated that country was in those days. It's somewhat irrelevant as they weren't checking this age group in the study. However, I do see your point.
I wonder how prevalent the Spanish Flu was in China in the early 1900's. I don't know how isolated that country was in those days. It's somewhat irrelevant as they weren't checking this age group in the study. However, I do see your point.
Missouriwatcher
Editor, Senior Moderator
Re: Can You Get H1N1 More Than Once?
If WHO didn't think you could get H1N1 more than once, why would they recommend it in the yearly flu vax for the southern hemisphere 2010?
If WHO didn't think you could get H1N1 more than once, why would they recommend it in the yearly flu vax for the southern hemisphere 2010?
gsgs
Registered User
Re: Can You Get H1N1 More Than Once?
I think you can get it more than once, but are less likely
when you had it or are vaxed.
Also it should be milder then in average.
1st wave hotspots New York, London, Boston,Philadelphia,...
seem to be somehow
protected now, they have less ILI than other regions.
1918 has genes from American birds, not Eurasian
I think you can get it more than once, but are less likely
when you had it or are vaxed.
Also it should be milder then in average.
1st wave hotspots New York, London, Boston,Philadelphia,...
seem to be somehow
protected now, they have less ILI than other regions.
1918 has genes from American birds, not Eurasian
Re: Can You Get H1N1 More Than Once?
Likely because only a percentage of the population got H1N1 the first time around. Lots of opinions but, so far, I have not seen evidence confirming you can get H1N1 more than once (without antigenic drift).
Likely because only a percentage of the population got H1N1 the first time around. Lots of opinions but, so far, I have not seen evidence confirming you can get H1N1 more than once (without antigenic drift).
Re: Can You Get H1N1 More Than Once?
That and because of manufacturing capacity and trying to marry seasonal demand with pandemic demand. There is still the need to reach many,many more people with vaccine in other (poorer) countries, and not jsut the third and developing world either. All current capacity has been purchased I think, leaving many other individuals uncovered in other countries that may be far behind in the queue to receive pandemic vax. It is a complex situation.
That and because of manufacturing capacity and trying to marry seasonal demand with pandemic demand. There is still the need to reach many,many more people with vaccine in other (poorer) countries, and not jsut the third and developing world either. All current capacity has been purchased I think, leaving many other individuals uncovered in other countries that may be far behind in the queue to receive pandemic vax. It is a complex situation.
madgirl9876
Member
Re: Can You Get H1N1 More Than Once?
My infant tested positive for type A (but not subtyped) in August. His doctor refuses to give him the vaccine for H1N1, as she said he almost definitely had H1N1 due to when he got sick. She said this comes directly from what their infectious disease specialist is telling them to do- people who tested positive for type A flu during the summer won?t be able to get the vaccination.
Is this against what the CDC is recommending?
Please move this if I put this in the wrong thread- posted it here because it is related to the possibility of getting the flu twice.
My infant tested positive for type A (but not subtyped) in August. His doctor refuses to give him the vaccine for H1N1, as she said he almost definitely had H1N1 due to when he got sick. She said this comes directly from what their infectious disease specialist is telling them to do- people who tested positive for type A flu during the summer won?t be able to get the vaccination.
Is this against what the CDC is recommending?
Please move this if I put this in the wrong thread- posted it here because it is related to the possibility of getting the flu twice.
Re: Can You Get H1N1 More Than Once?
Can You Get H1N1 More Than Once?
The answer depends on what you mean by the question.
The significant variables that I believe concern many of us are significant disease and immunity.
After taking a long journey in search of the answer to this question, the "bottom line" qualified answer is:
If you have had significant exposure to H1N1 that results in significant symptomatic illness with sustained fever and thereby mount an immune response that results in high titer (at least 80) immunity, then any subsequent infection by the same non-drifted virus should be dealt with quickly by your immune system and you will not suffer significant illness again.
Period, end of story.
Still reading? Well , of course, the answer can be different if you are talking about asymptomatic infections, non fever infections, carrier states, defective immune systems, virus population subsets, co-infections, etc..
If you are a "googler" , you might find these links provide some food for thought.
http://www.jimmunol.org/cgi/content/abstract/183/6/3569
http://www.emergingworlds.com/ch_viruses_detail.cfm?vPageid=98
http://www.iayork.com/MysteryRays/2009/09/17/stealth-influenza/
The next link I find very useful:
http://www.cdc.gov/media/transcripts/2009/t091009.htm
snip: Even in places that were hard hit with the H1N1 virus last spring, at most, 5% to 10% of people were ill with disease even if many people were infected without having any symptoms. We think the vast majority of people in a given community are vulnerable or susceptible to this virus.
snip end
I hope this is helpful, at least in placing the question in context.
Can You Get H1N1 More Than Once?
The answer depends on what you mean by the question.
The significant variables that I believe concern many of us are significant disease and immunity.
After taking a long journey in search of the answer to this question, the "bottom line" qualified answer is:
If you have had significant exposure to H1N1 that results in significant symptomatic illness with sustained fever and thereby mount an immune response that results in high titer (at least 80) immunity, then any subsequent infection by the same non-drifted virus should be dealt with quickly by your immune system and you will not suffer significant illness again.
Period, end of story.
Still reading? Well , of course, the answer can be different if you are talking about asymptomatic infections, non fever infections, carrier states, defective immune systems, virus population subsets, co-infections, etc..
If you are a "googler" , you might find these links provide some food for thought.
http://www.jimmunol.org/cgi/content/abstract/183/6/3569
http://www.emergingworlds.com/ch_viruses_detail.cfm?vPageid=98
http://www.iayork.com/MysteryRays/2009/09/17/stealth-influenza/
The next link I find very useful:
http://www.cdc.gov/media/transcripts/2009/t091009.htm
snip: Even in places that were hard hit with the H1N1 virus last spring, at most, 5% to 10% of people were ill with disease even if many people were infected without having any symptoms. We think the vast majority of people in a given community are vulnerable or susceptible to this virus.
snip end
I hope this is helpful, at least in placing the question in context.
gsgs
Registered User
Re: Can You Get H1N1 More Than Once?
then I've read some days ago, that they now believe
20%-40% may have got it already in New York City,
including asymptomatic.
mayn who were vaccinated still got it , even in years with
a good vaccine-match.
many were infected in wave 1 and wave 2 in 1918,
although there was some protection
then I've read some days ago, that they now believe
20%-40% may have got it already in New York City,
including asymptomatic.
mayn who were vaccinated still got it , even in years with
a good vaccine-match.
many were infected in wave 1 and wave 2 in 1918,
although there was some protection
Missouriwatcher
Editor, Senior Moderator
Re: Can You Get H1N1 More Than Once?
If I get the A(H1N1) 2009 vax this year (I always get my yearly seasonal vax), next year I will get a second A(H1N1) if it is included in the seasonal vax. Then, the following year, the same thing??? I understand the need to simplify, but can I get too much?
If I get the A(H1N1) 2009 vax this year (I always get my yearly seasonal vax), next year I will get a second A(H1N1) if it is included in the seasonal vax. Then, the following year, the same thing??? I understand the need to simplify, but can I get too much?
Re: Can You Get H1N1 More Than Once?
North44: re our earlier discussions about the potential effects of influenza strains that attack dendritic cells as a potential mechansim for lowered long term immunity post infection, this new animal study adds to the picture. I look forward to more data and studies on the mechanisms of 2009 H1N1 pathogenisis, to work out if this could be an effect that is specific to certain flu strains or generalised for influenza, to a greater or lesser extent (perhaps why people are generally vulnerable to the same parent strain each influenza season, or can require multiple infections before they achieve long lasting immunity to an entirely novel strain???)
J Exp Med. 2009 Sep 28. [Epub ahead of print]
Dendritic cells are crucial for maintenance of tertiary lymphoid structures in the lung of influenza virus-infected mice.
Geurtsvankessel CH, Willart MA, Bergen IM, van Rijt LS, Muskens F, Elewaut D, Osterhaus AD, Hendriks R, Rimmelzwaan GF, Lambrecht BN. - Department of Pulmonary Medicine and 2 Department of Virology, Erasmus University Medical Center, Rotterdam 3000 CA, Netherlands.
Tertiary lymphoid organs (TLOs) are organized aggregates of B and T cells formed in postembryonic life in response to chronic immune responses to infectious agents or self-antigens. Although CD11c(+) dendritic cells (DCs) are consistently found in regions of TLO, their contribution to TLO organization has not been studied in detail. We found that CD11c(hi) DCs are essential for the maintenance of inducible bronchus-associated lymphoid tissue (iBALT), a form of TLO induced in the lungs after influenza virus infection. Elimination of DCs after the virus had been cleared from the lung resulted in iBALT disintegration and reduction in germinal center (GC) reactions, which led to significantly reduced numbers of class-switched plasma cells in the lung and bone marrow and reduction in protective antiviral serum immunoglobulins. Mechanistically, DCs isolated from the lungs of mice with iBALT no longer presented viral antigens to T cells but were a source of lymphotoxin (LT) beta and homeostatic chemokines (CXCL-12 and -13 and CCL-19 and -21) known to contribute to TLO organization. Like depletion of DCs, blockade of LTbeta receptor signaling after virus clearance led to disintegration of iBALT and GC reactions. Together, our data reveal a previously unappreciated function of lung DCs in iBALT homeostasis and humoral immunity to influenza virus.
PMID: 19808255 [PubMed - as supplied by publisher]
North44: re our earlier discussions about the potential effects of influenza strains that attack dendritic cells as a potential mechansim for lowered long term immunity post infection, this new animal study adds to the picture. I look forward to more data and studies on the mechanisms of 2009 H1N1 pathogenisis, to work out if this could be an effect that is specific to certain flu strains or generalised for influenza, to a greater or lesser extent (perhaps why people are generally vulnerable to the same parent strain each influenza season, or can require multiple infections before they achieve long lasting immunity to an entirely novel strain???)
J Exp Med. 2009 Sep 28. [Epub ahead of print]
Dendritic cells are crucial for maintenance of tertiary lymphoid structures in the lung of influenza virus-infected mice.
Geurtsvankessel CH, Willart MA, Bergen IM, van Rijt LS, Muskens F, Elewaut D, Osterhaus AD, Hendriks R, Rimmelzwaan GF, Lambrecht BN. - Department of Pulmonary Medicine and 2 Department of Virology, Erasmus University Medical Center, Rotterdam 3000 CA, Netherlands.
Tertiary lymphoid organs (TLOs) are organized aggregates of B and T cells formed in postembryonic life in response to chronic immune responses to infectious agents or self-antigens. Although CD11c(+) dendritic cells (DCs) are consistently found in regions of TLO, their contribution to TLO organization has not been studied in detail. We found that CD11c(hi) DCs are essential for the maintenance of inducible bronchus-associated lymphoid tissue (iBALT), a form of TLO induced in the lungs after influenza virus infection. Elimination of DCs after the virus had been cleared from the lung resulted in iBALT disintegration and reduction in germinal center (GC) reactions, which led to significantly reduced numbers of class-switched plasma cells in the lung and bone marrow and reduction in protective antiviral serum immunoglobulins. Mechanistically, DCs isolated from the lungs of mice with iBALT no longer presented viral antigens to T cells but were a source of lymphotoxin (LT) beta and homeostatic chemokines (CXCL-12 and -13 and CCL-19 and -21) known to contribute to TLO organization. Like depletion of DCs, blockade of LTbeta receptor signaling after virus clearance led to disintegration of iBALT and GC reactions. Together, our data reveal a previously unappreciated function of lung DCs in iBALT homeostasis and humoral immunity to influenza virus.
PMID: 19808255 [PubMed - as supplied by publisher]
Re: Can You Get H1N1 More Than Once?
Vibrant62: I appreciate the theory of why the immune response may be blunted post influenza infection. But, are there other (perhaps unknown) mechanisms that kick in to both fight infection and heighten immunity? I keep coming back to wanting to know what actually happens in real-life situations (human).
Vibrant62: I appreciate the theory of why the immune response may be blunted post influenza infection. But, are there other (perhaps unknown) mechanisms that kick in to both fight infection and heighten immunity? I keep coming back to wanting to know what actually happens in real-life situations (human).
Laidback Al
Well-known member
Re: Can You Get H1N1 More Than Once?
Thanks FluFreak. As you note, this assume that the strain of novel A(H1N1) has not changed and that you have sufficient antibodies to combat a reinfection. Antibody titer testing is necessary for absolute certainty.
Thanks FluFreak. As you note, this assume that the strain of novel A(H1N1) has not changed and that you have sufficient antibodies to combat a reinfection. Antibody titer testing is necessary for absolute certainty.
Re: Can You Get H1N1 More Than Once?
Thank you Flufreak. This concept has always been my understanding of the immune response to influenza infection and appears to be what happens in the clinical situation. One needs to remember that antibody levels wain over the years, but the immune system usually retains "memory" and is able to respond quickly and appropriately when the need arises (assuming no antigenic drift). Your caveats appear to be correct as well.