Polio vaccines are vaccines used to prevent poliomyelitis polio. The inactivated polio vaccines are very safe. The first successful demonstration of a polio vaccine was by Hilary Koprowski in , with a live attenuated virus which people drank. Interruption of person-to-person transmission of the virus by vaccination is important in the global polio eradication ,  since no long-term carrier state exists for poliovirus in individuals with normal immune function, polio viruses have no nonprimate reservoir in nature,  and survival of the virus in the environment for an extended period of time appears to be remote. The duration of immunity induced by IPV is not known with certainty, although a complete series is thought to provide protection for many years. Oral polio vaccines proved to be superior in administration, eliminating the need for sterile syringes and making the vaccine more suitable for mass vaccination campaigns.
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Polio vaccines are vaccines used to prevent poliomyelitis polio. The inactivated polio vaccines are very safe. The first successful demonstration of a polio vaccine was by Hilary Koprowski in , with a live attenuated virus which people drank. Interruption of person-to-person transmission of the virus by vaccination is important in the global polio eradication ,  since no long-term carrier state exists for poliovirus in individuals with normal immune function, polio viruses have no nonprimate reservoir in nature,  and survival of the virus in the environment for an extended period of time appears to be remote.
The duration of immunity induced by IPV is not known with certainty, although a complete series is thought to provide protection for many years. Oral polio vaccines proved to be superior in administration, eliminating the need for sterile syringes and making the vaccine more suitable for mass vaccination campaigns.
OPV also provided longer-lasting immunity than the Salk vaccine, as it provides both humoral immunity and cell-mediated immunity. OPV produces excellent immunity in the intestine , the primary site of wild poliovirus entry, which helps prevent infection with wild virus in areas where the virus is endemic. The live virus also has stringent requirements for transport and storage, which are a problem in some hot or remote areas. As with other live-virus vaccines, immunity initiated by OPV is probably lifelong.
The trivalent against wild types 1, 2, and 3 OPV has been used to nearly eradicate polio infection worldwide.
In countries with the highest levels of coverage and the lowest risks of importation and transmission, the WHO recommends a primary series of 3 IPV injections, with a booster dose after an interval of six months or more if the first dose was administered before 2 months of age. Mild redness or pain may occur at the site of injection.
Oral polio vaccine results in vaccine-associated paralytic poliomyelitis in about three per million doses. A potential, but rare, adverse effect of the OPV is its known ability to recombine to a form that causes neurological infection and paralysis.
The vaccine-derived attenuated virus is normally excreted from vaccinated people for a limited period. Thus, in areas with poor sanitation and low vaccination coverage, the spontaneous reversal of the vaccine-derived virus to a virulent form and its spreading in the environment can lead to unvaccinated people becoming infected.
To combat this the World Health Organization WHO in , decided to switch from the trivalent polio vaccine to the bivalent polio vaccine. In , the rhesus monkey kidney cells used to prepare the poliovirus vaccines were determined to be infected with the Simian Virus In , SV40 was found to cause tumors in rodents. SV40 was found to be present in stocks of the injected form of the polio vaccine IPV in use between and The published findings from the study revealed no increased incidence of cancer in persons who may have received vaccine containing SV During the race to develop an oral polio vaccine, several large-scale human trials were undertaken.
In Africa, the vaccines were administered to roughly one million people in the Belgian territories now the Democratic Republic of the Congo , Rwanda , and Burundi. These hypotheses, however, have been conclusively refuted. Recent local opposition to vaccination campaigns have evolved due to lack of adequate information,   often relating to fears that the vaccine might induce sterility.
The Salk vaccine, IPV, is based on three wild, virulent reference strains, Mahoney type 1 poliovirus , MEF-1 type 2 poliovirus , and Saukett type 3 poliovirus , grown in a type of monkey kidney tissue culture Vero cell line , which are then inactivated with formalin. In the United States, vaccine is administered along with the tetanus , diphtheria , and acellular pertussis vaccines DTaP and a pediatric dose of hepatitis B vaccine.
OPV is an attenuated vaccine , produced by the passage of the virus through nonhuman cells at a sub physiological temperature, which produces spontaneous mutations in the viral genome. Other groups, led by Hilary Koprowski and H. Cox , developed their own attenuated vaccine strains. In , the National Institutes of Health created a special committee on live polio vaccines.
The various vaccines were carefully evaluated for their ability to induce immunity to polio, while retaining a low incidence of neuropathogenicity in monkeys. Large-scale clinical trials performed in the Soviet Union in late s to early s by Mikhail Chumakov and his colleagues demonstrated safety and high efficacy of the vaccine. In , trivalent OPV TOPV was licensed, and became the vaccine of choice in the United States and most other countries of the world, largely replacing the inactivated polio vaccine.
The result was a substantial reduction in the number of poliomyelitis cases, even from the much-reduced levels following the introduction of the Salk vaccine. OPV is usually provided in vials containing 10—20 doses of vaccine. A single dose of oral polio vaccine usually two drops contains 1,, infectious units of Sabin 1 effective against PV1 , , infectious units of the Sabin 2 strain, and , infectious units of Sabin 3.
The vaccine contains small traces of antibiotics — neomycin and streptomycin —but does not contain preservatives. In a generic sense, vaccination works by priming the immune system with an ' immunogen '. Stimulating immune response, by use of an infectious agent, is known as immunization. The development of immunity to polio efficiently blocks person-to-person transmission of wild poliovirus, thereby protecting both individual vaccine recipients and the wider community.
The development of two polio vaccines led to the first modern mass inoculations. The last cases of paralytic poliomyelitis caused by endemic transmission of wild virus in the United States occurred in , with an outbreak among the Amish in several Midwest states.
Two separate teams, led by John Kolmer and Maurice Brodie respectively, developed polio vaccines and reported their results at the annual meeting of the American Public Health Association in November Despite promising results, both were cancelled as a result of the angry reaction from other researchers, as vaccinated children had died in both studies; no researchers dared attempt a polio vaccine for another 20 years.
He had developed an attenuated poliovirus vaccine, which he tested in about 10, children across much of the United States and Canada. Maurice Brodie , MD — , a young researcher at New York University and the New York City Health Department , presented his results afterwards, but the feelings of the researchers were already unfavorable before he started because of Kolmer's report.
However, other researchers believed that the one case was likely caused by the vaccine, and two more possible cases were reported later.
After this meeting, Brodie, whose polio vaccine was at least partially effective and reasonably safe, and who developed several ground-breaking ideas about vaccination whose validity was confirmed two decades later with the development of the Salk vaccine, was immediately fired and had trouble finding employment again. Brodie died three and a half years later. A breakthrough came in when a research group headed by John Enders at the Children's Hospital Boston successfully cultivated the poliovirus in human tissue in the laboratory.
In March , Thomas H. Weller was attempting to grow varicella virus in embryonic lung tissue. He had inoculated the planned number of tubes when he noticed that there were a few unused tubes.
He retrieved a sample of mouse brain infected with polio virus and added it to the remaining test tubes, on the off chance that the virus might grow. The varicella cultures failed to grow, but the polio cultures were successful. This development greatly facilitated vaccine research and ultimately allowed for the development of vaccines against polio.
Enders and his colleagues, Thomas H. Weller and Frederick C. Robbins , were recognized in for their labors with a Nobel Prize in Physiology or Medicine. During the early s, polio rates in the U. Also working at Lederle was Polish-born virologist and immunologist Hilary Koprowski of the Wistar Institute in Philadelphia, who tested the first successful polio vaccine, in Koprowski's attenuated vaccine was prepared by successive passages through the brains of Swiss albino mice. By the seventh passage, the vaccine strains could no longer infect nervous tissue or cause paralysis.
After one to three further passages on rats, the vaccine was deemed safe for human use. After the child suffered no side effects, Koprowski enlarged his experiment to include 19 other children. James Lewis, and Lorraine Friedman, which required years of subsequent testing. Salk went on CBS radio to report a successful test on a small group of adults and children on 26 March ; two days later, the results were published in JAMA. Salk's vaccine was then used in a test called the Francis Field Trial, led by Thomas Francis , the largest medical experiment in history at that time.
The test began with about 4, children at Franklin Sherman Elementary School in McLean, Virginia ,   and eventually involved 1. Roosevelt , whose paralytic illness was generally believed to have been caused by polio. In the U.
S, following a mass immunization campaign promoted by the March of Dimes , the annual number of polio cases fell from 35, in to 5, by In April , soon after mass polio vaccination began in the US, the Surgeon General began to receive reports of patients who contracted paralytic polio about a week after being vaccinated with Salk polio vaccine from Cutter pharmaceutical company, with the paralysis limited to the limb the vaccine was injected into.
In response the Surgeon General pulled all polio vaccine made by Cutter Laboratories from the market, but not before cases of paralytic illness had occurred. Wyeth polio vaccine was also reported to have paralyzed and killed several children. It was soon discovered that some lots of Salk polio vaccine made by Cutter and Wyeth had not been properly inactivated, allowing live poliovirus into more than , doses of vaccine.
In May , the National Institutes of Health and Public Health Services established a Technical Committee on Poliomyelitis Vaccine to test and review all polio vaccine lots and advise the Public Health Service as to which lots should be released for public use.
These incidents reduced public confidence in polio vaccine leading to a drop in vaccination rates. At the same time that Salk was testing his vaccine, both Albert Sabin and Hilary Koprowski continued working on developing a vaccine using live virus.
During a meeting in Stockholm to discuss polio vaccines in November , Sabin presented results obtained on a group of 80 volunteers, while Koprowski read a paper detailing the findings of a trial enrolling people. For this work, Sabin was given the medal of the Order of Friendship Among Peoples, described as the Soviets' highest civilian honor,  despite having become an American during the height of the cold war.
Sabin's oral vaccine using live virus came into commercial use in Once Sabin's oral vaccine became widely available, it supplanted Salk's injected vaccine, which had been tarnished in the public's opinion by the Cutter incident , in which Salk vaccines prepared by one company resulted in several children dying or becoming paralyzed.
An enhanced- potency IPV was licensed in the United States in November , and is currently the vaccine of choice there. Polio was eliminated in the Americas by In March , India was declared a polio-free country. Although poliovirus transmission has been interrupted in much of the world, transmission of wild poliovirus does continue and creates an ongoing risk for the importation of wild poliovirus into previously polio-free regions.
If importations of poliovirus occur, outbreaks of poliomyelitis may develop, especially in areas with low vaccination coverage and poor sanitation.
As a result, high levels of vaccination coverage must be maintained. In response, the Armenian government put out a notice asking Syrian Armenians under age 15 to get the polio vaccine.
Polio vaccination programs have received resistance from some people in Pakistan, Afghanistan, and Nigeria the three countries as of with remaining polio cases. Some Muslim religious leaders believe that the vaccines are secretly being used for sterilization of Muslims.
On 11 September , two unidentified gunmen associated with the Pakistani Taliban, Jamaat-ul-Ahrar, shot Zakaullah Khan, a doctor who was administering polio vaccines in Pakistan. The leader of the Jamaat-ul-Ahrar claimed responsibility for the shooting and says that the group will continue to keep doing these kinds of attacks. This resistance to and skepticism of vaccinations has consequently slowed down the polio eradication process within the three remaining countries.
A misconception has been present in Pakistan that polio vaccine contained haram ingredients and could cause impotence and infertility in male children, leading some parents not to have their children vaccinated.
Attacks on polio vaccination teams have also occurred, thereby hampering international efforts to eradicate polio in Pakistan and globally, since the virus can be carried by travelers.
Economic impact of introducing the injectable inactivated polio vaccine in Colombia. The cost was analyzed from the perspective of the insurer costs throughout life and society cases of VAPP and disability-adjusted life years [DALYs] prevented. According to the model, 2 to 4 cases of VAPP could be anticipated in the following two years. Key words: Poliovirus vaccine, oral; poliovirus vaccine, inactivated; cost-benefit analysis; disability-adjusted life years; mass vaccination; Colombia.
Starting in , a major change in the poliomyelitis vaccination policy occurred, facilitated by substantial progress toward worldwide poliomyelitis eradication. In , two doses of IPV were recommended to start the primary series, followed by two doses of either poliovirus vaccine. As of January , an all-IPV schedule is currently being implemented in the United States for routine childhood vaccination. Several unusual features are associated with the major public health policy change from an all-OPV to a sequential schedule, including 1 the process of involving a neutral party i. The IOM assisted in the evaluation of the national poliomyelitis vaccination policy in and again in
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