4/06/2010

Polio Vaccine






Polio Vaccine

A polio vaccine is a medicine that is given to prevent polio. There are two general types. One type is the inactivated vaccine, which contains no live poliovirus. The other type is the oral vaccine, which contains live but weakened poliovirus. The vaccine was first licensed in 1955. Where and when it is given depends on whether the person is an adult or a child.

What Is a Polio Vaccine?

As you might expect, the polio vaccine is a medicine that is given to prevent polio(also called poliomyelitis).
 
(Click Polio Prevention for more information about preventing polio.)
 

Types of Polio Vaccine

There are two general types of polio vaccine. One type is an inactivated vaccine (the IPV), meaning that the vaccine contains no live poliovirus. The other type is an oral vaccine, which contains live but weakened poliovirus.
 
(Click Vaccine-Associated Paralytic Poliomyelitis for more information about the oral polio vaccine and its risks.)
 

History of Polio and the Polio Vaccine

A 1916 polio epidemic in the United States killed 6,000 people and paralyzed 27,000 more. In the early 1950s, there were more than 20,000 cases of polio each year. Vaccination began in 1955. By 1960, the number of polio disease cases had dropped to about 3,000. The last cases of paralytic poliomyelitis caused by endemic polio transmissionof wild virus in the United States were in 1979, when an outbreak occurred among the Amish in several Midwestern states. The success of the polio vaccine in the United States and other countries sparked a worldwide effort to eliminate polio.
 
The inactivated polio vaccine was licensed in 1955 and was used extensively from that time until the early 1960s. In 1961, the oral vaccine was licensed. This was the vaccine of choice in the United States and most other countries after its introduction. However, the oral vaccine can cause a rare but serious reaction called vaccine-associated paralytic poliomyelitis. When an enhanced-potency inactivated polio vaccine became available in 1998, it was recommended that the oral vaccine no longer be used. In 2000, the use of the oral vaccine in the Unites States was discontinued.



Oral Polio Vaccine

The oral polio vaccine is quite effective in preventing the disease. However, because it poses a slight risk of a rare but serious condition, its use in the United States has been discontinued -- an enhanced-potency inactivated polio vaccine is now used instead. The oral vaccine is still used for polio prevention in many other parts of the world.

What Is the Oral Polio Vaccine?

Oral polio vaccine (OPV) contains live but weakened poliovirus. It is highly effective in polio prevention. However, because of the risk of a rare but serious condition called vaccine-associated paralytic poliomyelitis, use of the oral polio vaccinein the United States was discontinued in 2000.
 

History of Polio and the Oral Vaccine

A 1916 polio epidemic in the United States killed 6,000 people and paralyzed 27,000 more. In the early 1950s, there were more than 20,000 cases of polio each year.
 
The first polio vaccine was licensed in 1955. This was an inactivated polio vaccine (IPV), meaning it did not contain any live poliovirus. By 1960, the number of cases had dropped to about 3,000. In 1961, an oral vaccine was licensed. Following its introduction, as the number of cases continued to drop. In 1979, the last cases of paralytic poliomyelitis caused by wild poliovirus in the United States occurred.
 
The success of polio vaccination in the United States and other countries sparked a worldwide effort to eliminate this disease.
 
In 1998, an enhanced-potency inactivated polio vaccine became available. Because oral polio vaccine can cause a rare but serious reaction called vaccine-associated paralytic poliomyelitis, its use was not recommended. In 2000, the use of this vaccine in the Unites States was discontinued.
 

How Effective Is the Oral Polio Vaccine?

Oral polio vaccine is highly effective in producing immunity to poliovirus. A single dose produces immunity in approximately 50 percent of recipients. Three doses will produce immunity to all three poliovirus types in more than 95 percent of recipients. As with other live-virus vaccines, immunity from oral polio vaccine is probably lifelong.



Comparing Oral and Inactivated Polio Vaccines

There are two general polio vaccine types. One type is inactivated polio vaccine(IPV), meaning that the vaccine contains no live poliovirus. The other is live oral poliovaccine, which contains live but weakened poliovirus. Until recently, the oral vaccine was recommended for most children in the United States. It helped rid the United States of polio, and is still used in many parts of the world (largely because it is less expensive than the inactivated polio vaccine).
 
Both vaccines give immunity to polio, but the oral form is better at keeping the disease from spreading to other people. However, for a few people (about 1 in 2.4 million), oral polio vaccine actually causes polio (known as vaccine-associated paralytic polio).
 
Since the risk of getting polio in the United States is now extremely low, experts believe that using the oral vaccine is no longer worth the slight risk, except in limited circumstances, which your doctor can describe. The polio shot (inactivated polio vaccine) does not cause polio.
 
(Click Polio Vaccine to learn more about the inactivated vaccine.)
 

Vaccine-Associated Paralytic Poliomyelitis

Vaccine-associated paralytic poliomyelitis is a rare adverse reaction following live oral polio vaccine. It is caused by vaccine-derived poliovirus. One case occurred for every 2 to 3 million doses of oral vaccine administered. This resulted in 8 to 10 cases of vaccine-associated paralytic poliomyelitis each year in the United States.
 
From 1980 through 1999, vaccine-associated paralytic poliomyelitis accounted for 95 percent of all cases of paralytic poliomyelitis reported in the United States.
 
(Click Vaccine-Associated Paralytic Poliomyelitis to learn more about this rare but serious reaction to the oral polio vaccine.)

















Hacer un Amigo es una Gracia
Tener un amigo es un Don
Conservar un Amigo es una Virtud
Ser un Amigo es un Honor

The Polio Crusade

THE POLIO CRUSADE IN AMERICAN EXPERIENCE A GOOD VIDEO THE STORY OF THE POLIO CRUSADE pays tribute to a time when Americans banded together to conquer a terrible disease. The medical breakthrough saved countless lives and had a pervasive impact on American philanthropy that ... Continue reading..http://www.pbs.org/wgbh/americanexperience/polio/

Erradicación de La poliomielitis

Polio Tricisilla Adaptada