Seasonal influenza vaccines

US Influenza incidence by state

Hopefully, all students enrolled in BIO230 have gotten their annual seasonal flu vaccine. As of January 15th, influenza incidence was reported as “widespread” in 17 states, including Pennsylvania by the Centers for Disease Control in Atlanta, and we have several more weeks of flu season to go before numbers of cases begin to significantly decline. As you likely know, influenza vaccines are typically only good for each year’s influenza outbreak, which is why a new vaccine is necessary each year. The reason that influenza vaccines are only effective against a single season’s outbreak is because the strain of virus is somewhat different from year to year, due to the inherent variability of the virus. Since vaccines are only effective against that year’s strain of virus, and because of the fact that varieties of influenza virus can infect and propagate in a wide variety of mammals and birds, it is unlikely that influenza will ever be a disease that can be eradicated, in the manner that smallpox has been. Which brings me to a fascinating science article that I found via the American Society of Microbiology news website.  Researchers at Emory University and the University of Chicago examined the response of patients who had been infected with the H1N1 strain of flu during the 2009 flu season. Nine patients who were sick with this strain of flu were studied for their ability to make immune molecules called antibodies, which are the proteins that help to protect us from infectious diseases via a number of mechanisms. Antibodies are powerful mediators of immunity, but they are also incredibly specific: an antibody which is effective against one influenza virus will not recognize  other varieties of influenza virus. This is why we must get a new influenza vaccine each year, as the antibodies we make when we get a flu shot will not be effective against next year’s flu.

This is where the story gets interesting. When the researchers examined the antibodies made by these patients against the H1N1 variety of influenza virus, they found several of the antibody types recognized other varieties of influenza virus in a process called “cross-reactivity.” Through very sensitive techniques, the researchers eliminated the possibility that the patients had been infected with one of these other flu types, and that the antibodies being made were in fact due to infection with H1N1.  To verify the usefulness of these H1N1 antibodies, researchers put the antibodies into mice, which were then infected with influenza. Mice receiving the antibodies were protected from the effects of the virus.

What is the next step? This isn’t necessarily a novel finding; antibodies which cross-react with different influenza strains have been described before, but not to the same sort of detail as this study does.  The studies will likely continue to be confirmed, and the protective nature of the immune response studies in mice and other animal models of influenza infection. At that point, the parts of the virus that induce the production of the protective antibodies seen in this study can be incorporated into the seasonal flu vaccine. This in turn can hopefully lead to the development of a flu vaccine that lasts more than one year, and offers more effective way of protecting the population from this deadly disease.

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About ycpmicro

My name is David Singleton, and I am an Associate Professor of Microbiology at York College of Pennsylvania. My main course is BIO230, a course taken by allied-health students at YCP. Views on this site are my own.

Posted on January 30, 2011, in Important, Lecture, Microbes in the News. Bookmark the permalink. 9 Comments.

  1. UPDATE!!! One week along with the flu reports, we have gone from 17 states with “widespread” influenza reports, to 24 states with “widespread” influenza reports. And the latest report is the week ending 22 January 2011, or almost two weeks ago!

  2. Joseph Williams

    This article proves one of the problems humans are facing today. We are in a constant battle for finding vaccines for viruses, bacteria, and other microorganisms. Still, one of the main problems with vaccines is convincing people that they work and the chance of having side effects is small. I work in a pharmacy that gives vaccines for influenza, shingles,etc… There are a lot of people who come in and ask questions about the vaccines and how harmful they are to humans. Fortunately, vaccines are known to help protect humans; however, whenever there is a story of a side effect that puts a person in a life threatening condition, people start to rethink getting vaccinated. Coming up with the vaccines is only part of the problem. Convincing people that they work is the challenge.

    • Here’s my opinion voiced in this very forum last semester.
      Flu surveillance update for the week ending 29 January 2011; “widespread” flu in 30 states, with regional influenza in most of the rest of the states. The only states remaining of the lower 48 with lower flu levels are: Utah, Oregon, and Washington. I wouldn’t plan on taking refuge in Utah, however, because it is surrounded by Wyoming, Colorado, New Mexico, Arizona, and Nevada, all of which are “widespread.” The border between Utah and Idaho remains in OK shape for now.

  3. UPDATE!!!! Week 5, ending 5 February 2011: influenza now “widespread” in 39 states, and the only states with less than “regional” status are Utah, Oregon, and Hawaii. Oh, and my home state of Delaware too. Still, I’m probably not going to count Delaware. Sorry Mom and Dad.

  4. UPDATE!!11! Week 7, ending 19 February 2011: influenza now “widespread” in 44 states. Our only “sporadic influenza” holdout in the continental US is Oregon. Utah has now gone to “regional” influenza, and Delaware has bypassed that milestone to go to “widespread.” That didn’t take long.

  5. UPDATE!!! Week 8, ending 26 February 2011: influenza incidence still “widespread” in 44 states, with “regional” in Hawaii, Florida, Alabama, Mississippi, and Utah, with Oregon at “local,” a step more severe than last week. Will it go any higher than this????

  6. UPDATE!!!! Week 9, ending 05 March 2011: well, it looks like we are beginning to diminish in intensity a little bit, as the annual influenza season starts to drop. Widespread influenza in the majority of the continental US states, but Oregon and Utah are back to “local” activity, and 9 states are at “regional” status. Looks like we can go across the river to New Jersey, as it is one of the states that appears to be dropping back.

  7. UPDATE!!! Week 10, ending 12 March 2011: Definitely turned the tide on influenza this season, at least as plotted on a state by state basis. The CDC Influenza Surveillance report indicates that many of the southern states have gone back down to “regional” status, with 16 of the lower 48 at that status or lower! North Carolina has even made the jump from “widespread” all the way down to “sporadic” influenza, so I’m now planning my vacation to the Outer Banks, or at the very least am going to pick either UNC or Duke in my NCAA brackets.

  8. UPDATE!!!! Week 11, ending 19 March 2011: latest update from the CDC flu surveillance map indicates we know have 18 states (including PA, sorry folks!) with “widespread” influenza, 22 states down a notch to “regional” status, 7 states down to “local” status, and 3 states (including DE, hi Mom and Dad!) down to “sporadic.” It looks like North Carolina jumped back up a notch in status, so you should cancel your holidays.

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