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Can You Get Swine Flu More Than Once?

Posted

Specializes in Too many to list.

http://dailymail.com/News/200911041062

I have been hearing anecdotal information about this happening for months now but these are the first positive test confirmations that I have seen confirming that this is indeed possible.

Dr. Debra Parsons, a pediatrician at Kid Care West in Cross Lanes, said both she and her son came down with identical flu-like symptoms in August.

... a more specific follow-up "sub-typing" test at the state lab confirmed she had H1N1.

Parsons and her son recovered from the symptoms but in October they struck again and were much worse, she said. Both had body aches, fever, chills, wheezing, and shortness of breath.

This time Parsons swabbed both herself and her son, and both tests came back positive for Influenza A. She said she pushed for further testing to determine the strain, and the lab ran an immunofluorescence test on the specimens. They again tested positive for H1N1, she said.

Parsons' second swab was sent to the state lab Wednesday for even further testing and results should be returned in a couple of days or sent to the Centers for Disease Control for follow-up tests, she said.

When the initial test came back positive again, Parsons said she also contacted the CDC to see if it's possible for someone to contact the swine flu twice.

She said officials at the CDC told her Saturday that it is possible.

(hat tip pfi/clawdia)

Edited by indigo girl

Purple_Scrubs, BSN, RN

Specializes in School Nursing. Has 8 years experience.

Fantastic. So, will the vaccine even help, I wonder? If there are sub-types or even the slightest mutation, we might be right back to square one.

Immunity is such a mystery. I know for a fact I have been exposed on several occasions, yet I have not come down with anything more severe than a slight sore throat and congestion (which is par for the course for me this time of year anyway, chronic post nasal drip and allergies). I continue to be amazed that I have not become ill. Maybe they need to study my blood for antibodies, LOL!

Edited by Purple_Scrubs
typo

Multicollinearity, BSN, RN

Specializes in Acute Care Psych, DNP Student. Has 4 years experience.

I'm trying to wrap my mind around getting the virus more than once without any kind if viral mutation or shift.

indigo girl

Specializes in Too many to list.

We have been hearing several reports from people in Mexico in particular saying that they thought they were infected again, but they had not been tested so no one new for sure. Dr. Niman over at Recombinomics had this to say back on 10 October. I never posted it because there was no other confirmation, but I remembered it because it made some sense and was interesting. I am only posting a few paragraphs.

http://www.recombinomics.com/News/10100901/H1N1_Infection_Titer.html

The recently released data on the clinical trial in Australia suggests that such re-infections may be linked to low titers generated during mild infections. Although prior pandemic H1N1 infections were among exclusion criteria, 31% of enrollees had titers of 40 or more at baseline. Since there is little cross reactivity between contemporary seasonal H1N1 and pandemic swine H1N1, the baseline titers are almost certainly due to pandemic H1N1 infections that were not disclosed or not know the enrollee. Since many who are infected experience mild disease, including infections without fever, it is likely that many or most of these enrollees had mild infections.

Figure two suggests that although these enrollees had prior antibodies, the titers were relatively low (the vast majority were between 40 and 160) and most had significant improvements (increases of 4 fold or more) after a single injection, suggesting the weak responses to earlier natural infections would provide limited immunological protection, which would support common re-infections.

These data would also explain the limited level of drift, because naïve hosts as well as those with prior mild infections would be susceptible to re-infections, which would limit the selective pressure offered by genetic drift. Indeed, in recent CDC weekly updates, only one isolate has shown reduced titers to the pandemic vaccine target. However, this recently identified isolate may signal the start or accelerated drift as more of the target population develop higher antibody levels.

or it was surpressed, not over come, and was allowed to come forth again....

indigo girl

Specializes in Too many to list.

CDC confirms Kanawha County pediatrician had swine flu -- twice

http://www.dailymail.com/News/Kanawha/200911230838

Parsons says she's spoken with CDC representatives about the results, and they said the double infection isn't all that unbelievable.

"They said this happens every year with seasonal flu, so there's no reason to expect that it wouldn't happen with swine flu," Parsons said. "Every flu strain can change a little bit."

The pediatrician says there may have been a tiny change in the virus that stopped her immune system from recognizing it or her body never built up immunity to it.

(hat tip pfi/monotreme)

canoehead, BSN, RN

Specializes in ER. Has 30 years experience.

A HA!! So the vaccine is not the holy grail of protection is was touted to be!

I had my suspicions...does this mean that everybody gets to wear masks for 12 hours a day?

indigo girl

Specializes in Too many to list.

Vaccination was not the topic.

indigo girl

Specializes in Too many to list.

Dr. Henry Niman remarks on the positive confirmation of H1N1 re-infections noted in the first post of this thread. His theory on how this occurs, and what it could mean for future cases is unproven but interesting nonetheless. I hope that he is not correct, but that remains to be seen. The prediction of a third wave is probably right on target, however.

The mutation he mentions is also of interest. There has been quite a bit of speculation about what it could mean, but there is no agreement on its significance. It is now being reported in many countries just in the past week, maybe because they are now actively looking for it.

...the H1N1 virus was evolving slowly, reflecting an ease of infection of a naïve population. The jump from swine H1N1 into humans allows for infections with low doses of virus. Low concentration of virus produces a mild infection and a weak antibody response. The rapid spread creates widespread antibody, but the low level allows for re-infection from individuals with a higher viral load. A higher viral load can be created in a school environment, where some students could be infected multiple times because of frequent contact with infected students.

Thus, the increased viral load could overcome the weak immune-response and re-infect those infected earlier, leading to a second wave. However, the higher viral load leads to more serious infections, especially for those not infected in the first wave. Consequently more previously health young adults develop more serious symptoms, leading to an increase in hospitalizations and deaths. The higher viral load, especially when combined with receptor binding domain changes such as D225G can lead to the type of cases seen in Ukraine, where a high percentage of young adults develop infections that destroy both lungs in a matter of a few days.

In many areas, including Ukraine, this wave is subsiding, but the holiday season will lead to new infections by viruses with regional markers, leading to a third wave in early 2010.

Full comments at: http://www.recombinomics.com/News/11250901/H1N1_X2.html

indigo girl

Specializes in Too many to list.

South Korea Reports First Suspected A/H1N1 Re-infection Case

http://ow.ly/164ui2

Health officials said the baby was admitted to a hospital in the southeastern city of Gimhae in September due to high fever, and was confirmed to be infected with the virus by Green Cross Reference Laboratory that tests samples provided by local clinics and hospitals. The baby later recovered after receiving antiviral treatment.

However, the baby was sent to hospital again on Nov. 20 as she had a temperature reaching 39.1 C and showed respiratory-related symptoms, and later was tested positive for the A/H1N1 strain, the officials said.

Samples taken from the baby will be sent to the Korea Centers for Disease Control and Prevention to check its genetic sequence to find out whether it is a mutated strain of the new flu, the officials added.

(hat tip flutrackers/Dutchy)

Ok, so does this mean if you've had a mild case, then if you are reinfected, would you be LESS ill because you've had it before? Or would you be MORE ill? Hmmm.....

indigo girl

Specializes in Too many to list.

Ok, so does this mean if you've had a mild case, then if you are reinfected, would you be LESS ill because you've had it before? Or would you be MORE ill? Hmmm.....

More importantly, you would, imo be less likely to have a fatal case because you would have at least some protective antibodies. It still sounds like the baby was sick enough though she has survived, and the pediatrician in the first link as well.

Personally, I would rather boost antibody via vaccine rather than get sick twice. The flu is no picnic. I hate getting sick.

canoehead, BSN, RN

Specializes in ER. Has 30 years experience.

Vaccination was not the topic.

You are talking about being exposed twice and getting sick twice...vaccination is a form of exposure and is pertinent to the discussion.

indigo girl

Specializes in Too many to list.

You are talking about being exposed twice and getting sick twice...vaccination is a form of exposure and is pertinent to the discussion.

True enough. These are two related topics then.

Usually getting sick means that you don't catch something again, however, repeated exposure with a high enough viral load when you only have a weak antibody response means that you could get sick again. And, perhaps the viral strain is different enough that your not so great antibody response isn't going to be enough to protect you entirely. This may have happened in the pediatrician's case, for example.

You are concerned that vaccination will not be effective at preventing infection. It might not be completely effective in all cases, but for most people, it usually is enough, though there are always exceptions to everything.

No flu vax including the seasonal is 100% effective, and no one ever claimed it was the Holy Grail. Vaccines are always chasing a moving target because influenza viruses mutate quickly. However, with antibodies, while complete protection from morbidity might not be entirely possible for some people, prevention of mortality is far more

likely, and for that reason alone, the vax is well worth it especially for pregnant women, and kids.

For the majority of people, the vax is likely to prevent flu given enough time to develop peak antibodies before being exposed to the virus. After the vax, as per Dr. Niman of Recombinomics, "you might be able to detect antibodies in 8-10 days, but maximum response will take about 3 weeks." You are still at risk from an infection

shortly after vaccination, and as per Niman, vaccination "might make the infection worse initially because the immune system is battling the vaccine, and could be more easily overwhelmed by a new infection. Full protection is defined by peak antibody levels."

A major reason for vaccinating as many people as quickly as possible is to help slow down, and then eventually halt the pandemic with herd immunity. The pandemic is going to continue until there are no more susceptible hosts. Herd immunity is going to happen eventually either by enough of us getting sick and recovering or by vaccination.

And, this balancing act, is happening all while the virus is trying to escape from the vaccine which of course, it will eventually succeed in doing.

A different more up to date form of this swine flu strain will then have to be included into the seasonal vaccine for next year along with whatever seasonal influenza is showing up this year (almost none so far but it's early yet).

indigo girl

Specializes in Too many to list.

Reinfection with 2009 influenza H1N1

You are talking about being exposed twice and getting sick twice...vaccination is a form of exposure and is pertinent to the discussion.

More on this here:

http://www.virology.ws/2009/12/28/reinfection-with-2009-influenza-h1n1/

In healthy individuals, the first encounter with a virus leads to a primary antibody response. When an infection occurs with the same or a similar virus, a rapid antibody response occurs that is called the secondary antibody response. Antibodies are critical for preventing many viral infections, including influenza. But reinfection may occur if we encounter the same virus before the primary response is complete.

Could reinfection also occur after immunization with influenza vaccine? Yes, if the immunized individual encounters the virus before the primary antibody response matures, which occurs in 3-4 weeks. This is more likely to occur during pandemic influenza when circulation of the virus is more extensive than in non-pandemic years.

lamazeteacher

Specializes in OB, HH, ADMIN, IC, ED, QI.

I hadn't seen this thread earlier, and appreciate its appearance now, as I'm someone who had negative tests for H1N1 in the first 48 hours of my 2 illnesses with flu-like symptoms at the end of August '09 and in mid Oct.'09.

When the CDC came out with a statement saying that rhinovirus was around at those times, I figured that one of those infections could have been that.

Since viral tests are expensive, and antibody testing even more expensive, that takes priority in decision making regarding accurate diagnosing of this and many other infections. If we had Federally subsidized central labs that specialized in testing of flu antibodies, that would be cost effective; and with companies that deliver specimens within hours, to locations in the USA, it's certainly doable. It would also provide more and new jobs.....

Once the Reform of Health Care bill/program has hit its stride, that enhanced availability and lower cost of testing would be admirable goals, especially since the prediction of waves of the same infections can be accurately predicted, now. That is all the more reason for the bill's passage. It will save lives at many levels of health care! Please call or send emails to your Senators supporting immediate passage of the (less than perfect) bill, without religious restrictions (abortion issues), everyone!

The United States of America supposedly doesn't mix religion with state issues, according to established Federal law. The fact that a Senator has blatantly ignored that, in return for a promise that his state's health care will be paid by all the other states, makes me break protocol by raising the issue here, off topic. Sorry for that, and I hope it will give rise to another thread, or that no discussion further about that will occur here, in this vein. :offtopic:

Best wishes to everyone for a healthy, happy New Year! :bell:

Edited by lamazeteacher
clarity

indigo girl

Specializes in Too many to list.

Pandemic (H1N1) 2009 Reinfection, Chile

http://www.cdc.gov/eid/content/16/1/pdfs/156.pdf

To the Editor: Since March 2009, influenza A pandemic (H1N1) 2009 has spread worldwide (1), and in South America, Chile was 1 of the countries most affected by the pandemic, with 21.4 cases among every 1,000 persons. Treatment guidelines in Chile recommended antiviral drug treatment with oseltamivir or zanamivir for 5 days for all patients with confirmed or suspected virus subtype H1N1 infection (2). In persons with seasonal influenza, specific antibody responses reach peak titers by 4 weeks after infection and confer protection against the infecting strain and closely related strains (3). Reinfection is rarely seen in nonpandemic influenza A. We report on 3 patients with confirmed influenza A pandemic (H1N1) 2009 reinfection after successful treatment with oseltamivir.

Shedding of seasonal influenza A virus ceases within 5–7 days during natural infection and during infections treated with neuraminidase inhibitors (4). Although clearing of virus after the first infection was not documented in the 3 patients described here, it is unlikely that virus persisted between the 2 episodes of influenza since each of the patients fully recovered after specific antiviral drug treatment. However, we cannot rule out that patient 2 may have never cleared the virus due to her immune suppression.

As described by mathematical modeling (5), the 3 patients described were susceptible to reinfection with pandemic (H1N1) 2009 due to the high rate of community infection and to their incomplete immunologic protection within the period of reexposure. During the current pandemic of influenza subtype H1N1, healthcare workers and patients should be aware that symptomatic reinfection might occur after a first episode of infection.

(hat tip flutrackers/Roro)

True enough. These are two related topics then.

Usually getting sick means that you don't catch something again, however, repeated exposure with a high enough viral load when you only have a weak antibody response means that you could get sick again. And, perhaps the viral strain is different enough that your not so great antibody response isn't going to be enough to protect you entirely. This may have happened in the pediatrician's case, for example.

You are concerned that vaccination will not be effective at preventing infection. It might not be completely effective in all cases, but for most people, it usually is enough, though there are always exceptions to everything.

No flu vax including the seasonal is 100% effective, and no one ever claimed it was the Holy Grail. Vaccines are always chasing a moving target because influenza viruses mutate quickly. However, with antibodies, while complete protection from morbidity might not be entirely possible for some people, prevention of mortality is far more

likely, and for that reason alone, the vax is well worth it especially for pregnant women, and kids.

For the majority of people, the vax is likely to prevent flu given enough time to develop peak antibodies before being exposed to the virus. After the vax, as per Dr. Niman of Recombinomics, "you might be able to detect antibodies in 8-10 days, but maximum response will take about 3 weeks." You are still at risk from an infection

shortly after vaccination, and as per Niman, vaccination "might make the infection worse initially because the immune system is battling the vaccine, and could be more easily overwhelmed by a new infection. Full protection is defined by peak antibody levels."

A major reason for vaccinating as many people as quickly as possible is to help slow down, and then eventually halt the pandemic with herd immunity. The pandemic is going to continue until there are no more susceptible hosts. Herd immunity is going to happen eventually either by enough of us getting sick and recovering or by vaccination.

And, this balancing act, is happening all while the virus is trying to escape from the vaccine which of course, it will eventually succeed in doing.

A different more up to date form of this swine flu strain will then have to be included into the seasonal vaccine for next year along with whatever seasonal influenza is showing up this year (almost none so far but it's early yet).

If a person isn't guaranteed 100% immunity from the vax and could possibly have a light case of flu, would they even be tested and could they run around spreading the H1N1 without knowing it?