With flu season among us, research of the influenza impact
in the southern hemisphere is emerging and preparing physicians for a possibly
severe season. Based on reports from the Australian Government Department of
Health they had 215,280 influenza cases by mid- October 2017 in comparison to
59,022 cases just six years earlier. The strain of influenza that was observed
was Influenza A (H3N2), with the vaccine only being 10% effective. Though the
vaccine for the northern hemisphere, specifically the United States, is not
necessarily identical, it is of similar composition prompting worry for a very
low effectiveness of this year’s influenza vaccine. With a low effectiveness of
the vaccine it leaves the young, the old, and those with preexisting conditions
more vulnerable for developing this disease and have severe outcomes.
But what
makes it so these vaccines aren’t as effective from one year to the next? As
explained by Catherine Paules, M.D. and her team, vaccines are strain specific
and from year to year the vaccines require changes six to nine months prior to
administration. This means that the composition of the vaccine is developed
based on research from global virus surveillance data from the five to eight
months beforehand, and not necessarily up to date when the vaccine is created.
Influenza viruses are antigenic, and able to adapt and bind to a product of the
immune system inhibiting their action, making it hard to create a completely
effective vaccine against the disease.
Catherine
Paules and team also presents the information of how not all vaccines are made
the same way, in means of the sources of the substrates they are produced from.
In the United States, most influenza vaccines are propagated in eggs, which
have properties of effecting proteins within the vaccine virus and thus making
it less effective. There are other ways to produce the viruses used for in
vaccines including in cell culture or by expressing specific viral using recombinant
DNA technologies. Research done by a study on the 2016-2017-influenza vaccine
that was developed in eggs showed to be less effective in regards to possible
mutations in the virus caused by the egg. With this year’s influenza vaccine
also being developed in eggs, it is proposed that based on the research from the
Southern hemisphere flu season that the United States will experience low
effectiveness of the vaccine for Influenza A. It is proposed that in the years
to come, for further research to be done on the development of the vaccines and
that to make a “universal” vaccine that can handle the antigenic changes of the
viruses and even the other strains that are observed season to season.
Citations:
Paules, C., Sullivan, S., Subbarao, K., Fauci, A. (November
29,2017). Chasing Seasonal
Influenza-
The Need for a Universal Influenza Vaccine. Retrieved from
http://www.nejm.org/doi/10.1056/NEJMp1714916
The CDC mentions that "flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population..." which is pretty significant. Yet, "current flu vaccines tend to work better against influenza B and influenza A(H1N1) viruses and offer lower protection against influenza A(H3N2) viruses". It seems to me that though information is there, people in general don't really know that A. -flu shots vary from year to year, B.- that the most common viruses are chosen for that year in somewhat of a guessing game and C. that the each year's flu vaccine will protect them from 3-4 versions of a highly mutative illness. In your opinion should the public be more educated about specific vaccine this?
ReplyDeleteHere's the link: https://www.cdc.gov/flu/about/qa/vaccineeffect.htm
DeleteThis is great information Morgan. I know several people who believe that the flu shot gets you sick or initiates an inflammatory response. Your blog shows that flu shot needs to be better developed and more effective but can it actually create flu like symptoms? Well according to the CDC several studies have been conducted where two groups of patients were given shots, one being the flu vaccine and the other just saline. Out of the two groups the only difference in post vaccination reactions were redness at the point of injection and occasionally mild fever and flu like symptoms. So generally people would just be overreacting to these mild flu like symptoms. I believe that any real flu symptoms caused post vaccine would be caused by the lack of efficiency that you describe and not the vaccine itself.
ReplyDeleteReference:
Influenza (Flu). (2017, October 03). Retrieved from https://www.cdc.gov/flu/about/qa/misconceptions.htm