America May Over-vaccinate, According To New Research

[Guest guest]

America May Over-vaccinate, According To New Research

ScienceDaily (Nov. 8, 2007) — A new study published in the New England Journal

of Medicine* by Oregon Health & Science University researchers suggests that

timelines for vaccinating and revaccinating Americans against disease should

possibly be reevaluated and adjusted. The study shows that in many cases, the

established duration of protective immunity for many vaccines is greatly

underestimated. This means that people are getting booster shots when their

immunity levels most likely do not require it.

" The goal of this study was to determine how long immunity could be maintained

after infection or vaccination. We expected to see long-lived immunity following

a viral infection and relatively short-lived immunity after vaccination,

especially since this is the reasoning for requiring booster vaccinations.

Surprisingly, we found that immunity following vaccination with tetanus and

diphtheria was much more long-lived than anyone realized and that antibody

responses following viral infections were essentially maintained for life, "

explained Mark Slifka, Ph.D. Slifka serves as an associate scientist at the

Vaccine and Gene Therapy Institute with joint appointments at the Oregon

National Primate Research Center and the department of molecular microbiology

and immunology in the OHSU School of Medicine.

" We want to emphasize that proper vaccination is vital for protecting people

against infectious disease. We also need to mention that over-vaccinating the

population poses no health or safety concerns -- it may just be unnecessary

under certain circumstances. What our study found was that the lifespan of

protective immunity for certain vaccines is much longer than previously thought.

So what does this mean? Based on this data and other studies, we may want to

consider adjusting some of our recommended vaccination schedules. Doing so may

reduce the number of required shots that are administered each year in this

country while at the same time help extend limited health care resources, " Dr.

Slifka explained.

To conduct the research, Slifka and his colleagues evaluated 630 blood samples

from a total of 45 study participants. In the case of some participants,

archived serum samples provided data going back as far as 26 years. Once

gathered, the data was then analyzed to determine the level of immunity in each

individual for measles, mumps, rubella, chickenpox (Varicella-zoster virus),

mononucleosis (Epstein-Barr virus), tetanus and diphtheria over an extended

period of time. Upon further examination, researchers found that antibody

responses caused by viruses such as measles mumps, and rubella remained at

protective levels for several decades and in most cases, for life. This is

interesting because these three viruses were classically described as " childhood

infections " because it was rare to be infected twice in a lifetime.

The research also reconfirmed a previous finding by Slifka and his colleagues:

that the duration of immunity after smallpox vaccination is much longer than

previously thought. In that earlier study published in the journal Nature

Medicine in 2003, these OHSU researchers observed surprisingly long-lived

antiviral antibody responses but they were unable to measure the slow rate of

decline. In this current study, they demonstrate that this type of immunity is

maintained with a calculated half-life of 92 years -- a number that is

substantially longer than the estimate of only 3 to 5 years of immunity

following vaccination that was previously proposed by experts at the Centers for

Disease Control and Prevention.

" Another example is the tetanus vaccine, " said Slifka. " Doctors are told that

vaccination is effective for a period of 10 years -- but after that, people

should be revaccinated. Based on our studies and the work of others, once a

person has received their primary series of vaccinations they are likely to be

protected for at least three decades. Indeed, other countries such as Sweden

have changed their vaccination policies and doctors are advised to offer tetanus

revaccination only once every 30 years. " Importantly, this has not resulted in

any increase in the number of tetanus cases in Sweden and demonstrates

first-hand that switching from the 10-year to 30-year policy is safe and

effective. Taking this small step in vaccination scheduling could save hundreds

of millions of dollars on health care here in the US. "

*The results are published in the November 8 edition of the journal.

This research was supported by the United States Public Health Service.

Adapted from materials provided by Oregon Health & Science University.

http://www.sciencedaily.com/releases/2007/11/071107170749.htm

_________________________________________________________________

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[Guest guest]

America May Over-vaccinate, According To New Research

ScienceDaily (Nov. 8, 2007) — A new study published in the New England Journal

of Medicine* by Oregon Health & Science University researchers suggests that

timelines for vaccinating and revaccinating Americans against disease should

possibly be reevaluated and adjusted. The study shows that in many cases, the

established duration of protective immunity for many vaccines is greatly

underestimated. This means that people are getting booster shots when their

immunity levels most likely do not require it.

" The goal of this study was to determine how long immunity could be maintained

after infection or vaccination. We expected to see long-lived immunity following

a viral infection and relatively short-lived immunity after vaccination,

especially since this is the reasoning for requiring booster vaccinations.

Surprisingly, we found that immunity following vaccination with tetanus and

diphtheria was much more long-lived than anyone realized and that antibody

responses following viral infections were essentially maintained for life, "

explained Mark Slifka, Ph.D. Slifka serves as an associate scientist at the

Vaccine and Gene Therapy Institute with joint appointments at the Oregon

National Primate Research Center and the department of molecular microbiology

and immunology in the OHSU School of Medicine.

" We want to emphasize that proper vaccination is vital for protecting people

against infectious disease. We also need to mention that over-vaccinating the

population poses no health or safety concerns -- it may just be unnecessary

under certain circumstances. What our study found was that the lifespan of

protective immunity for certain vaccines is much longer than previously thought.

So what does this mean? Based on this data and other studies, we may want to

consider adjusting some of our recommended vaccination schedules. Doing so may

reduce the number of required shots that are administered each year in this

country while at the same time help extend limited health care resources, " Dr.

Slifka explained.

To conduct the research, Slifka and his colleagues evaluated 630 blood samples

from a total of 45 study participants. In the case of some participants,

archived serum samples provided data going back as far as 26 years. Once

gathered, the data was then analyzed to determine the level of immunity in each

individual for measles, mumps, rubella, chickenpox (Varicella-zoster virus),

mononucleosis (Epstein-Barr virus), tetanus and diphtheria over an extended

period of time. Upon further examination, researchers found that antibody

responses caused by viruses such as measles mumps, and rubella remained at

protective levels for several decades and in most cases, for life. This is

interesting because these three viruses were classically described as " childhood

infections " because it was rare to be infected twice in a lifetime.

The research also reconfirmed a previous finding by Slifka and his colleagues:

that the duration of immunity after smallpox vaccination is much longer than

previously thought. In that earlier study published in the journal Nature

Medicine in 2003, these OHSU researchers observed surprisingly long-lived

antiviral antibody responses but they were unable to measure the slow rate of

decline. In this current study, they demonstrate that this type of immunity is

maintained with a calculated half-life of 92 years -- a number that is

substantially longer than the estimate of only 3 to 5 years of immunity

following vaccination that was previously proposed by experts at the Centers for

Disease Control and Prevention.

" Another example is the tetanus vaccine, " said Slifka. " Doctors are told that

vaccination is effective for a period of 10 years -- but after that, people

should be revaccinated. Based on our studies and the work of others, once a

person has received their primary series of vaccinations they are likely to be

protected for at least three decades. Indeed, other countries such as Sweden

have changed their vaccination policies and doctors are advised to offer tetanus

revaccination only once every 30 years. " Importantly, this has not resulted in

any increase in the number of tetanus cases in Sweden and demonstrates

first-hand that switching from the 10-year to 30-year policy is safe and

effective. Taking this small step in vaccination scheduling could save hundreds

of millions of dollars on health care here in the US. "

*The results are published in the November 8 edition of the journal.

This research was supported by the United States Public Health Service.

Adapted from materials provided by Oregon Health & Science University.

http://www.sciencedaily.com/releases/2007/11/071107170749.htm

_________________________________________________________________

Climb to the top of the charts!  Play Star Shuffle:  the word scramble challenge

with star power.

http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct