"Universal" flu vaccine on the horizon?

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TollandRCR
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"Universal" flu vaccine on the horizon?

#1

Post by TollandRCR » Sat May 12, 2012 12:36 pm

PJ had a thread about the 2009 pandemic of H1N1 influenza, which eventually killed 14,000 people. Flu may kill between 200,000 and 400,000 people each year, and the fear of a pandemic like that of "the Spanish flu" concerns WHO and other health agencies. TFB has several threads about nutz warning about the dangers of the flu vaccine or suing the Federal government about those dangers, but a scientific thread is missing.





Frontiers in b cell biology May 8, 2012 [link]Pandemic H1N1 influenza infection and vaccination in humans induces cross-protective antibodies that target the hemagglutinin stem,http://www.frontiersin.org/b_cell_biolo ... 7/abstract[/link]


Most monoclonal antibodies (mAbs) generated from humans infected or vaccinated with the 2009 pandemic H1N1 (pdmH1N1) influenza virus targeted the hemagglutinin (HA) stem. These anti-HA stem mAbs mostly used IGHV1-69 and bound readily to epitopes on the conventional seasonal influenza and pdmH1N1 vaccines. The anti-HA stem mAbs neutralized pdmH1N1, seasonal influenza H1N1 and avian H5N1 influenza viruses by inhibiting HA-mediated fusion of membranes and protected against and treated heterologous lethal infections in mice with H5N1 influenza virus. This demonstrated that therapeutic mAbs could be generated a few months after the new virus emerged. Human immunization with the pdmH1N1 vaccine induced circulating antibodies that when passively transferred, protected mice from lethal, heterologous H5N1 influenza infections. We observed that the dominant heterosubtypic antibody response against the HA stem correlated with the relative absence of memory B cells against the HA head of pdmH1N1, thus enabling the rare heterosubtypic memory B cells induced by seasonal influenza and specific for conserved sites on the HA stem to compete for T-cell help. These results support the notion that broadly protective antibodies against influenza would be induced by successive vaccination with conventional influenza vaccines based on subtypes of HA in viruses not circulating in humans.OK, I don't understand much of that either. It is the scientific backup for this article:





Biology News Net May 8, 2012 [link]H1N1 discovery paves way for universal flu vaccine: UBC research,http://www.biologynews.net/archives/201 ... earch.html[/link]


"Current flu vaccines target the head of the HA [a protein called hemagglutinin] to prevent infections, but because the flu virus mutates very quickly, this part of the HA changes rapidly, hence the need for different vaccines every flu season."





Vaccines contain bits of weak or dead germs that prompt the human immune system to produce antibodies that circulate in the blood to kill those specific germs. However, the research team found that the 2009 pandemic H1N1 vaccine induced broadly protective antibodies capable of fighting different variants of the flu virus.





"This is because, rather than attacking the variable head of the HA, the antibodies attacked the stem of the HA, neutralizing the flu virus," says Schrader. "The stem plays such an integral role in penetrating the cell that it cannot change between different variants of the flu virus."





The new discovery could pave the way to developing universal flu vaccines.There is speculation that a vaccine acting as did the H1N1 vaccine -- attacking the stem, not the head, of the protein -- could "make influenza pandemics and seasonal influenza a thing of the past."





There is also research underway on an alternative model for a vaccine, one that will boost T-cells to fight influenza viruses rather than create antibodies to the viruses.
“The truth is, we know so little about life, we don’t really know what the good news is and what the bad news is.” Kurt Vonnegut

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Addie
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Re: "Universal" flu vaccine on the horizon?

#2

Post by Addie » Thu Jan 03, 2019 12:32 pm

Salon
The same flu virus that caused the 1918 pandemic is back this year

H1N1, the same strain that killed over 50 million in the late 1910s, is back. Will another pandemic happen?


Flu season has officially begun, according to the Centers for Disease Control and Prevention, and this year the infamous strain known as H1N1 is dominant. That's the same strain that killed at least 50 million people and infected nearly one-third of the world’s population a century ago, between 1918 and 1920.

“Most flu activity so far this season is still being driven by H1N1 infections," Kristen Nordlund, a CDC spokesperson, told Salon in an email. Nordlund added that "in the last four weeks, H3N2 viruses have been most common in the southeastern part of the country,”

To date, there have been seven pediatric deaths associated with a mix of H1N1, H3N2 and influenza B virus infections, the CDC states. It is too early to tell if H1N1 will infect a majority of those who get the flu this year, bu it is worth asking: If it is, could it be as deadly as it was in 1918?

The short answer is no, and there are a few biological reasons why. First, Nordlund said, “influenza viruses are constantly changing,” which is one of the reasons why there is a new formulation for flu vaccines each year. In other words, the H1N1 strain from 100 years ago does not have exactly the same RNA as today's H1N1 strain.

As the CDC explains, flu viruses can change in two different ways, with different consequences for infectiousness. First, there's “antigenic drift,” something that happens in the genes of the virus over time as the virus reproduces. As a given virus spreads throughout one's body, mutations develop slowly — meaning someone who has antibodies against a given strain may find that their immune system does not recognize the newer mutations from that strain, hence getting sick again from the same strain.

The second way in which a flu virus changes is called an “antigenic shift.” While an antigenic drift happens gradually, a shift is sudden and involves two strains merging genetic material, creating a new strain spontaneously. Antigenic shifts particularly can lead to a pandemic, because people have little protection from the genes of the new virus. In the spring of 2009, a shift happened with an H1N1 strain, according to the CDC.

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