Polio Vaccine (IPV): When to Get Vaccinated Risks and Side Effects of Polio Vaccination Polio , an infectious disease caused by a virus that lives in the throat and intestinal tract , was once the leading cause of disability in the U.S. Since the introduction of the polio vaccine in 1955, the disease has been eradicated in the U.S. But the disease is still common in some developing countries and until it is eradicated worldwide, the risk of it spreading to the U.S. still exists. For that reason, the polio vaccination remains one of the recommended childhood immunizations . In most parts of the U.S., polio immunization is required before a child can start school. How the Polio Vaccination Is Given If you had the polio vaccination prior to 2000, you may have received the oral polio vaccine (OPV), which was made from a live poliovirus. Although the live virus vaccine was highly effective at protecting against polio, a few cases of polio per year were caused by the oral vaccine itself. In 2000, the U.S. switched to the inactivated polio vaccine (IPV).

Using an inactive (dead) form of the virus that cannot cause polio, the IPV is given as a shot in the arm or leg. Who Needs the Polio Vaccine Most people should get the polio vaccine when they are children. Children should be vaccinated with four doses of IPV at the following ages: A dose at 2 months A dose at 4 months A dose at 6-18 months A booster dose at 4-6 years IPV may be given at the same time as other vaccinations. Because most adults were vaccinated as children, routine polio vaccination is not recommended for people ages 18 and older who live in the U.S. But three groups of adults at higher risk for coming into contact with the poliovirus should consider polio vaccination. They are: Travelers to other parts of the world where polio is still common People who work in labs handling specimens that might contain polioviruses Health care workers who have close contact with a person who could be infected with the poliovirus If you fall into any of these three groups you should speak to your health care provider about the polio vaccination.

If you have never been vaccinated against polio, you should get three doses of IPV: The first dose at any time The second dose 1 to 2 months later The third dose 6 to 12 months after the second If you have had one or two doses of polio vaccine in the past you should get the remaining one or two doses. It doesn't matter how long it has been since the earlier dose or doses. Continued WHO | Poliomyelitis Poliomyelitis Jonas Salk, developer of Inactivated Polio Vaccines (IPV) Poliomyelitis is an acute communicable disease of humans caused by a human enterovirus of the Picornaviridae family. The virus is composed of a single-stranded, positive-sense RNA genome and a protein capsid. The 3 serotypes of poliovirus carry are antigenically distinct. Poliovirus is transmitted from one person to another by oral contact with secretions or faecal material from an infected person. Most poliovirus infections cause asymptomatic viral replication that is limited to the alimentary tract.

However, following an incubation period of approximately 7–10 days (range, 4–35 days), about 24% of those infected develop clinical signs such as fever, headache and sore throat (considered a minor illness). Paralytic poliomyelitis, experienced in <1% of poliovirus infections, occurs when the virus enters the central nervous system and replicates in anterior horn cells (motor neurons) of the spinal cord. When it multiplies in the nervous system, the virus can destroy nerve cells (motor neurons) which activate skeletal muscles. The affected muscles lose their function due to a lack of nervous enervation, a condition known as acute flaccid paralysis. In the most severe cases (bulbar polio), poliovirus attacks the motor neurons of the brain stem, reducing breathing capacity and causing difficulty in swallowing and speaking. Without respiratory support, bulbar polio can result in death. Polio can strike at any age, but affects mainly children under three. In May 1988 the World Health Assembly resolved to eradicate polio from the world.

As a result of this eradication program, the number of poliomyelitis cases have been reduced by over 99%, and the endemic circulation type 2 virus has been halted. However, a small number of countries have not yet succeeded in stopping endemic transmission of polio, resulting in small sporadic outbreaks caused by travellers. When poliovirus transmission is successfully halted, a globally coordinated programme of containment of remaining wild poliovirus stocks and a discontinuation of the live oral polio vaccine will be required. Polio Vaccines Poliovirus infection can provide lifelong immunity against the disease, but this protection is limited to the serotype involved. Infection with one type does not protect an individual against infection with the other two types. The development of effective vaccines to prevent paralytic polio was one of the major medical breakthroughs of the 20th century. Two different kinds of vaccine are available, an inactivated (killed) polio vaccine (IPV) and a live attenuated oral polio vaccine (OPV). The presence of neutralizing antibody against polioviruses is considered a reliable correlate of protection against poliomyelitis.

However, immunity induced by one serotype does not provide protection against the other two serotypes. Inactivated polio vaccine was first introduced in 1955 and is produced from wild-type poliovirus strains of each serotype that have been inactivated (killed) with formalin. As an injectable vaccine, it can be administered alone or in combination with other vaccines (e.g., diphtheria, tetanus, pertussis, hepatitis B, and haemophilus influenza). IPV has been used successfully to eradicate polio in a few countries, notably in Scandinavia and the Netherlands. In the numerous countries that have introduced to IPV over the last decade no evidence of continued circulation of poliovirus strains has been observed, indicating that IPV may successfully inhibit community transmission of poliovirus. Adverse events following administration of IPV are very mild and transient, and because it is a killed vaccine, there is no risk of the live-virus-associated risks associated with OPV use.

However, due to the risks associated with the large quantities of wild-type poliovirus(WPV) needed for IPV production, following the global cessation of poliovirus transmission high level containment of all manufacturing and quality control areas where live virus is handled must be implemented. Efforts are now under way to develop a new, inactivated polio vaccine more suited to the post-eradication environment. One such candidate is an inactivated vaccine produced from the attenuated Sabin strains. Oral polio vaccine was first introduced in 1961 and consists of a mixture of the three live attenuated poliovirus serotypes (Sabin types 1, 2 and 3), selected for their lower neurovirulence and reduced transmissibility. In addition to trivalent OPV (tOPV), which is used in many countries for routine or supplemental vaccination, monovalent OPVs, against type-1 (mOPV1) and against type-3 (mOPV3), have been licensed since 2005 for use in some countries. Monovalent OPVs against type-2 have been licensed, but are expected to be used primarily for stockpiles.

In 2009, 2 bivalent (type-1 and type-3) OPVs (bOPVs) were licensed. The mOPVs and bOPVs are used primarily during mass campaigns. In the end-stages of stopping endemic transmission, monovalent OPV containing only attenuated virus of one serotype has been increasingly employed to target areas where one serotype predominates. Three or more spaced doses of OPV normally generate a protective immune response against subsequent infections, although in some areas additional doses (seven or more) may be required to prevent paralytic disease. Following oral administration OPV strains produce a local immune response in the lining of the intestines which is the primary site for poliovirus replication. Mucosal immunity decreases the replication and excretion (shedding) of the virus, and thus provides a potential barrier to its transmission. This mechanism, combined with the ease of oral administration and the very low cost of the vaccine, have made it the vaccine of choice for the global eradication programme. Although OPV is a safe vaccine, on rare occasions adverse events may occur. Vaccine-associated paralytic poliomyelitis (VAPP) is the most important of these rare adverse events.

Cases of VAPP are clinically indistinguishable from poliomyelitis caused by WPV, but can be distinguished by laboratory analysis. Sabin viruses can spread in populations where the coverage of OPV is low and they can acquire the neurovirulence and transmissibility characteristics of WPV. This may result in polio cases and outbreaks as circulating vaccine-derived poliovirus (cVDPV). These serious events become increasingly unacceptable as the number of paralytic cases due to circulating wild poliovirus declines, and when transmission of wild virus ends, the complete cessation of paralytic disease due to poliovirus will lead to the end of OPV usage. Polio Vaccine Standardization Written Standards Inactivated Polio Vaccine (IPV) The requirements for poliomyelitis vaccine (inactivated) were first formulated in 1959 and revised in 1965. Following several advances in technology in vaccine production, the requirements were further updated in 1981 and amended in 1985.

At that time, the introduction of continuous cells for manufacture of poliomyelitis vaccine (inactivated) (IPV) was a novel development and when the control of products manufactured in continuous cells had been standardized, the requirements again updated in 2000. An addendum was added in 2003 which specifies steps to be taken to minimize the risk of reintroducing wild poliovirus from a vaccine manufacturing facility into the community after global certification of polio eradication. Replacement of Annex 2 of WHO Technical Report Series, No. 910 Meeting Reports pdf, 207kb Oral Polio Vaccine (OPV) Requirements for poliomyelitis vaccine (oral) were first formulated in 1962 and revised in 1966 and 1972 when an appendix detailing the production of OPV in human diploid cells was added. The Requirements were further updated 1982 following an accumulation of data particularly on the performance and evaluation of the monkey neurovirulence test and tests on the karyology of human diploid cells.

The recommendations were updated in 1989 to take account of the general requirements for the characterization of continuous cell lines for the preparation of biologicals which were adopted in 1985 and after a WHO Study Group concluded that, in principle, such cell lines are acceptable as substrates for the production of biologicals. The requirements were last revised in full in 1999 when new quality control tests were introduced for the vaccine including the test in TgPVR21 mice as an alternative to the monkey neurovirulence test for poliovirus type 3. An addendum was approved in 2000 to extend the use of this test to all three poliovirus serotypes. Polio Vaccine: MedlinePlus Drug Information Other names Why get vaccinated? Vaccination can protect people from polio. Polio is a disease caused by a virus. It is spread mainly by person-to-person contact. It can also be spread by consuming food or drinks that are contaminated with the feces of an infected person. Most people infected with polio have no symptoms, and many recover without complications. But sometimes people who get polio develop paralysis (cannot move their arms or legs). Polio can result in permanent disability.

Polio can also cause death, usually by paralyzing the muscles used for breathing. Polio used to be very common in the United States. It paralyzed and killed thousands of people every year before polio vaccine was introduced in 1955. There is no cure for polio infection, but it can be prevented by vaccination. Polio has been eliminated from the United States. But it still occurs in other parts of the world. It would only take one person infected with polio coming from another country to bring the disease back here if we were not protected by vaccination. If the effort to eliminate the disease from the world is successful, some day we won't need polio vaccine. Until then, we need to keep getting our children vaccinated. Who should get polio vaccine and when? Inactivated Polio Vaccine (IPV) can prevent polio. Children: Most people should get IPV when they are children. Doses of IPV are usually given at 2, 4, 6 to 18 months, and 4 to 6 years of age. The schedule might be different for some children (including those traveling to certain countries and those who receive IPV as part of a combination vaccine). Your healthcare provider can give you more information.

Adults: Most adults do not need polio vaccine because they were vaccinated as children. But some adults are at higher risk and should consider polio vaccination including: people traveling to areas of the world, laboratory workers who might handle polio virus, and healthcare workers treating patients who could have polio. These higher-risk adults may need 1 to 3 doses of IPV, depending on how many doses they have had in the past. There are no known risks to getting IPV at the same time as other vaccines. Who should not get IPV or should wait? Tell the person who is giving the vaccine: If the person getting the vaccine has any severe, life-threatening allergies.If you ever had a life-threatening allergic reaction after a dose of IPV, or have a severe allergy to any part of this vaccine, you may be advised not to get vaccinated. Ask your healthcare provider if you want information about vaccine components. If the person getting the vaccine is not feeling well. If you have a mild illness, such as a cold, you can probably get the vaccine today. If you are moderately or severely ill you should probably wait until you recover. Your doctor can advise you. What are the risks from IPV?

As with any medicine, there is a very remote chance of a vaccine causing a serious injury or death. The safety of vaccines is always being monitored. For more information, visit: Other problems that could happen after this vaccine: People sometimes faint after a medical procedure, including vaccination. Sitting or lying down for about 15 minutes can help prevent fainting and injuries caused by a fall. Tell your provider if you feel dizzy, or have vision changes or ringing in the ears. Some people get shoulder pain that can be more severe and longer-lasting than the more routine soreness that can follow injections. This happens very rarely. Any medication can cause a severe allergic reaction. Such reactions from a vaccine are very rare, estimated at about 1 in a million doses, and would happen within a few minutes to a few hours after the vaccination. With any medicine, including vaccines, there is a chance of side effects. These are usually mild and go away on their own, but serious reactions are also possible. Some people who get IPV get a sore spot where the shot was given. IPV has not been known to cause serious problems, and most people don't have any problems at all with it. What if there is a moderate or severe problem?

What should I look for? Look for anything that concerns you, such as signs of a severe allergic reaction, a very high fever, or unusual behavior.Signs of a serious allergic reaction can include hives, swelling of the face or throat, difficulty breathing, a fast heartbeat, dizziness, and weakness. These would start a few minutes to a few hours after the vaccination. What should I do? If you think it is a severe allergic reaction or other emergency that can't wait, call 9-1-1 or get to the nearest hospital. Otherwise, call your clinic.Afterward, the reaction should be reported to the Vaccine Adverse Event Reporting System (VAERS). Your doctor should file this report, or you can do it yourself through the VAERS web site at or by calling 1-800-822-7967. VAERS does not provide medical advice. The National Vaccine Injury Compensation Program The National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have been injured by certain vaccines.

Persons who believe they may have been injured by a vaccine can learn about the program and about filing a claim by calling 1-800-338-2382 or visiting the VICP website at . There is a time limit to file a claim for compensation. How can I learn more? Ask your healthcare provider. He or she can give you the vaccine package insert or suggest other sources of information. Call your local or state health department. Contact the Centers for Disease Control and Prevention (CDC): call 1-800-232-4636 ( 1-800-CDC-INFO ) or visit CDC's website at Polio Vaccine Information Statement. U.S. Department of Health and Human Services/Centers for Disease Control and Prevention National Immunization Program. 7/20/2016. Polio Vaccine - American Family Physician Please note: This information was current at the time of publication. But medical information is always changing, and some information given here may be out of date. For regularly updated information on a variety of health topics, please visit familydoctor.org , the AAFP patient education website.

Information from Your Family Doctor Polio Vaccine See related article on the poliovirus vaccine . What is polio? Poliomyelitis (polio, for short) is caused by a virus. The virus can be spread by drinking water with the polio virus in it. It can also be passed by close contact, such as kissing an infected person. Polio is a serious illness. It can cause paralysis (can't move your arms and legs) or even death. Before the first polio vaccine was developed in the 1950s, thousands of children got polio every year. Fortunately, the use of vaccines has made polio very rare today. How can polio be prevented? You can keep your children from getting polio by making sure they get the polio vaccine. What is the polio vaccine? A vaccine is a medicine you take to keep you from getting a disease. The polio vaccine comes in two forms. Inactivated polio vaccine (called IPV) is given by injection (a “shot”). Oral polio vaccine (called OPV) is given by drops in the mouth. Which vaccine should my child get? Both types of vaccine work well to protect against polio.

Your doctor will talk with you about which type is best for your child. The chart on the next page lists some of the pros and cons of each vaccine. For most children, a schedule that starts with IPV is recommended. When should my child be vaccinated? Most children get four doses of polio vaccine on this schedule: First dose when they are 2 months old. Second dose when they are 4 months old. Third dose when they are 6 to 18 months old. Last dose when they are 4 to 6 years old. Polio vaccine can be given as all shots (IPV), all drops (OPV), or a combination of both. If both vaccines are used, the shots are given first. Should my child get only shots or only drops? Your child shouldn't get the OPV drops if you, your child or anyone who takes care of your child can't fight infections, is taking long-term steroid medicines, has cancer or AIDS or HIV infection. Your child shouldn't get the IPV shots if he or she is behind on receiving the shots or is allergic to these medicines: neomycin, streptomycin or polymyxin B. What are the risks of the vaccine?

Vaccines carry a small risk of serious harm, such as a severe allergic reaction. On very rare occasions, OPV can cause polio because it contains live, but weakened, poliovirus. IPV can't cause polio because it does not contain live poliovirus. Most people have no problems from IPV or OPV. Top 20 Questions about Vaccination | History of Vaccines Top 20 Questions about Vaccination See the steps involved in manufacturing vaccines. Related Links Top 20 Questions about Vaccination Receiving an Immunization 2 Is the polio vaccine linked with cancer? How do vaccines work? Do they work against viruses and bacteria? Vaccines work to prime your immune system against future “attacks” by a particular disease. There are vaccines against both viral and bacterial pathogens, or disease-causing agents. When a pathogen enters your body, your immune system generates antibodies to try to fight it off. Depending on the strength of your immune response and how effectively the antibodies fight off the pathogen, you may or may not get sick. If you do fall ill, however, some of the antibodies that are created will remain in your body playing watchdog after you’re no longer sick.

If you’re exposed to the same pathogen in the future, the antibodies will ”recognize” it and fight it off. Vaccines work because of this function of the immune system. They’re made from a killed, weakened, or partial version of a pathogen. When you get a vaccine, whatever version of the pathogen it contains isn’t strong or plentiful enough to make you sick, but it’s enough for your immune system to generate antibodies against it. As a result, you gain future immunity against the disease without having gotten sick: if you’re exposed to the pathogen again, your immune system will recognize it and be able to fight it off. Some vaccines against bacteria are made with a form of the bacteria itself. In other cases, they may be made with a modified form of a toxin generated by the bacteria. Tetanus, for example, is not directly caused by the Clostridium tetani bacteria. Instead, its symptoms are primarily caused by tetanospasmin, a toxin generated by that bacterium. Some bacterial vaccines are therefore made with a weakened or inactivated version of the toxin that actually produces symptoms of illness. This weakened or inactivated toxin is called a toxoid.

A tetanus immunization, for example, is made with tetanospasmin toxoid. top Why aren’t all vaccines 100% effective? Vaccines are designed to generate an immune response that will protect the vaccinated individual during future exposures to the disease. Individual immune systems, however, are different enough that in some cases, a person’s immune system will not generate an adequate response. As a result, he or she will not be effectively protected after immunization. That said, the effectiveness of most vaccines is high. After receiving the second dose of the MMR vaccine (measles, mumps and rubella) or the standalone measles vaccine, 99.7% of vaccinated individuals are immune to measles. The inactivated polio vaccine offers 99% effectiveness after three doses. The varicella (chickenpox) vaccine is between 85% and 90% effective in preventing all varicella infections, but 100% effective in preventing moderate and severe chicken pox. top Why are there so many vaccines? Currently, the U.S. childhood vaccination schedule for children between birth and six years of age recommends immunizations for 14 different diseases.

Some parents worry that this number seems high, particularly since some of the diseases being vaccinated against are now extremely rare in the United States. Each disease for which vaccinations are recommended, however, can causes serious illness or death in unvaccinated populations, and might quickly begin to appear again if vaccination rates dropped. The United States has seen mumps outbreaks in recent years since vaccination rates have dropped, with severe complications and hospitalizations required for some patients. And before the introduction of the Hib (Haemophilus Influenzae Type b) vaccine, Hib meningitis affected more than 12,000 American children annually, killing 600 and leaving many others with seizures, deafness, and developmental disabilities. After introduction of the vaccine, the number of deaths from Hib dropped to fewer than 10 per year. Each vaccine on the schedule continues to be recommended because of the risks posed by wild infection. top Is natural immunity better than vaccine-acquired immunity? In some cases, natural immunity is longer-lasting than the immunity gained from vaccination. The risks of natural infection, however, outweigh the risks of immunization for every recommended vaccine.

For example, wild measles infection causes encephalitis (inflammation of the brain) for one in 1,000 infected individuals. Overall, measles infection kills two of every 1,000 infected individuals. In contrast, the combination MMR (measles, mumps and rubella) vaccine results in a severe allergic reaction only once in every million vaccinated individuals, while preventing measles infection. The benefits of vaccine-acquired immunity extraordinarily outweigh the serious risks of natural infection. (For more on this topic, see our Understanding Risks activity .) Additionally, the Hib (Haemophilus influenzae type b) and tetanus vaccines actually provide more effective immunity than natural infection. top Why do some vaccines require boosters? It’s not completely understood why the length of acquired immunity varies with different vaccines. Some offer lifelong immunity with only one dose, while others require boosters in order to maintain immunity. Recent research has suggested that the persistence of immunity against a particular disease may depend on the speed with which that disease typically progresses through the body.

If a disease progresses very rapidly, the immune system’s memory response (that is, the “watchdog antibodies” generated after a previous infection or vaccination) may not be able to respond quickly enough to prevent infection—unless they’ve been “reminded” about the disease fairly recently and are already watching for it. Boosters serve as a “reminder” to your immune system. Research is continuing on the persistence of immunity generated by vaccines. top My child was invited to a chickenpox party. Would it be better for my child to get the chickenpox this way? Why do we vaccinate against a mild disease like chickenpox? The idea of “pox parties” is generally tied to the perception of chickenpox as a harmless illness. Before the varicella vaccine became available, however, chickenpox infections required 10,000 hospitalizations and caused more than 100 deaths each year in the United States. Exposing a child to wild chickenpox puts him at risk for a severe case of the disease. Even uncomplicated cases of chickenpox cause children to miss a week or more of school, with a caregiver missing work to care for the sick child.

[1] Natural infection also means a risk of infecting others: while successful vaccination protects a child against chickenpox without this risk, children who are infected with chickenpox naturally are contagious. They can spread the disease to other people—not just other children, but also adults, who have a higher risk of complications from the disease. Meanwhile, vaccination for chickenpox typically prevents future infection with the disease. In the rare cases where individuals do not develop adequate protection from vaccination to prevent future infection, chickenpox infection is typically mild, results in fewer symptoms, and ends more quickly than natural infection. (People with this mild form are contagious, however, and should take care not to expose others to the virus.) top Can you get a disease from the vaccine that’s supposed to prevent it? And why do some vaccines have live pathogens but others have killed pathogens? Vaccines that are made with killed versions of pathogens—or with only a part of the pathogen—are not able to cause illness. When a person receives these vaccines, it is impossible for him or her to become ill with the disease.

Live, attenuated (or weakened) vaccines are theoretically capable of causing illness: because they can still replicate (though not well), mutation is possible, which can result in a virulent form of the pathogen. However, they are designed with this in mind, and attenuated to minimize this possibility. Reversion to virulent form is a problem with some forms of the oral polio vaccine (OPV), which is why only the inactivated form (IPV) is now used in the United States. It is important to note that attenuated vaccines can cause serious problems for individuals with weakened immune systems, such as cancer patients. These individuals may receive a killed form of the vaccine if one is available. If not, their doctors may recommend against vaccination. In such cases, individuals rely on herd immunity for protection. As to why some vaccines contain live pathogens and others contain killed pathogens, the reasons vary by illness. However, generally speaking, live, attenuated vaccines generate longer-lasting immunity than killed vaccines. Thus, killed vaccines are more likely to require boosters to maintain immunity. Killed vaccines, however, also tend to be more stable for storage purposes, and can’t cause illness.

The medical community must weigh these trade-offs in deciding which approach to use against a particular disease. top Can babies’ immune systems handle so many vaccines? Yes. Studies demonstrate that infants’ immune systems can handle receiving many vaccines at once—more than the number currently recommended. The immunization schedule is based on infants’ ability to generate immune responses, as well as when they are at risk of certain illnesses. For example, the immunity passed from mother to child at birth is only temporary, and typically does not include immunity against polio, hepatitis B, Haemophilus influenzae type b, and other diseases that can be prevented by vaccination. top Why is there a new flu vaccine every year? Unlike most vaccines, which contain the most common strains of a given pathogen (if more than one exists) and are rarely changed, the seasonal flu vaccine changes frequently, though one or more of the flu strains in the vaccine may be retained from one year to the next. This is because the strains of influenza viruses that circulate are constantly changing. Each year, researchers choose viruses for the vaccine based on which ones are likely to be circulating over the course of the coming flu season, thus providing protection against the most prevalent strains.

So when you get a seasonal flu vaccine, you’re usually not getting another “dose” of the same flu vaccine you were given before. Instead, you’re usually getting protection against a whole new batch of flu viruses. top What is herd immunity? Is it real? Does it work? Herd immunity, also known as community immunity, refers to the protection offered to everyone in a community by high vaccination rates. With enough people immunized against a given disease, it’s difficult for the disease to gain a foothold in the community. This offers some protection to those who are unable to receive vaccinations—including newborns and individuals with chronic illnesses—by reducing the likelihood of an outbreak that could expose them to the disease. top Why is allergy to eggs a contraindication to getting some vaccines? Some vaccines, including the majority of vaccines against influenza, are cultured in chicken eggs. During the process of creating the vaccine, the majority of the egg protein is removed, but there is some concern that these vaccines might generate an allergic reaction in individuals with an egg allergy.

A recent report found that the majority of children with egg allergies who were given a flu shot had no adverse reactions; about 5% of children in the studied group developed relatively minor reactions such as hives, the majority of which resolved without treatment. [2] Additional research is underway to study this issue further. In most cases, only people with a severe (life-threatening) allergy to eggs are recommended against receiving egg-based vaccines. Your doctor can provide specific information. top Do vaccines cause autism? No. Vaccines do not cause autism. This possibility was publicized after a 1998 paper by a British physician who claimed to have found evidence that the MMR (measles, mumps and rubella) vaccine was linked to autism. The potential link has been thoroughly explored; study after study has found no such link, and the original 1998 study has been formally withdrawn by The Lancet, which had originally published it. Studies were also done regarding the possibility of a link between the preservative thimerosal, which is used in some vaccines, and autism; again, no such link was found.

It’s likely that this misconception persists because of the coincidence of timing between early childhood vaccinations and the first appearance of symptoms of autism. top People say that vaccines are linked to long-term health problems such as multiple sclerosis, diabetes, and autism. Is that true? All vaccines have possible side effects. Most, however, are mild and temporary. Adverse effects from vaccines are monitored thoroughly via multiple reporting systems, and there is no evidence from these systems to support these claims. top The vaccine information sheet for my child’s recent vaccination listed lots of potential side effects. Why is vaccination recommended if it can cause all of these side effects? Every vaccine has potential side effects. Typically they are very mild: soreness at the injection site (for a vaccine delivered via a shot), headaches, and low-grade fevers are examples of common vaccine side effects. Serious side effects are possible, however, including severe allergic reactions. However, the occurrence of these side effects is extremely rare. (Your doctor can explain the risks for individual vaccines in detail; more information is also available from the Centers for Disease Control and Prevention.) When considering possible side effects from vaccination, it’s important to do so in context. While some possible side effects are serious, they are extremely rare.

It’s important to remember is that choosing not to vaccinate also has serious risks. Vaccines protect against potentially fatal infectious diseases; avoiding vaccination raises the risk of contracting those diseases and spreading them to others. top Do we do enough safety testing with vaccines? Vaccines are tested repeatedly before being approved, and continue to be monitored for adverse reactions after their release. See our article on vaccine testing and safety for more information and details about this topic. top Do vaccines have aborted fetal tissue? No. The rubella vaccine virus that is included in the MMR (measles, mumps and rubella) shot is cultured using human cell lines. The vaccine material is carefully separated from the cells in which is was grown before being used. Some of these cell lines were generated from fetal tissue that was obtained in the 1960s from legal abortions. No new fetal issue is required to generate rubella vaccine. top Isn’t it true that better hygiene and nutrition were responsible for decreases in deaths and disease rates, rather than vaccines? Improved hygiene and nutrition, among other factors, can certainly lower the incidence of some diseases.

Data documenting the number of cases of a disease before and after the introduction of a vaccine, however, demonstrate that vaccines are overwhelmingly responsible for the largest drops in disease rates. Measles cases, for example, numbered anywhere from 300,000 to 800,000 a year in the United States between 1950 and 1963, when a newly licensed measles vaccine went into widespread use. By 1965, U.S. measles cases were beginning a dramatic drop. In 1968 about 22,000 cases were reported (a drop of 97.25% from the height of 800,000 cases in just three years); by 1998, the number of cases averaged about 100 per year or less. A similar post-vaccination drop occurred with most diseases for which vaccines are available. Perhaps the best evidence that vaccines, and not hygiene and nutrition, are responsible for the sharp drop in disease and death rates is chickenpox.

If hygiene and nutrition alone were enough to prevent infectious diseases, chickenpox rates would have dropped long before the introduction of the varicella vaccine, which was not available until the mid-1990s. Instead, the number of chickenpox cases in the United States in the early 1990s, before the vaccine was introduced in 1995, was about four million a year. By 2004, the disease incidence had dropped by about 85%. top Why can’t we eradicate other diseases, as we did with smallpox? In theory, nearly any infectious disease for which an effective vaccine exists should be eradicable. With sufficient vaccination levels and coordination between public health organizations, a disease can be prevented from gaining a foothold anywhere; eventually, without anyone to infect, it must die off. (A notable exception is tetanus, which is infectious but not contagious: it’s caused by a bacterium commonly found in animal feces, among other places. Thus, tetanus could not be eradicated without completely removing the Clostridium tetani bacterium from the planet.) Smallpox is unusual, however, in the set of characteristics that made it susceptible to eradication.

Unlike many other infectious diseases, smallpox has no animal reservoir. That is, it can’t “hide” in an animal population and re-emerge to infect humans, while some diseases can do just that (yellow fever, for example, can infect some primates; if a mosquito then bites an infected primate, it can transmit the virus back to humans). Another obstacle to eradication for many infectious diseases is visibility. People with smallpox were highly visible: the smallpox rash was easily recognizable, so that new cases could be detected quickly. Vaccination efforts could be focused based on the location of the cases and potential exposure to other individuals. Polio, by contrast, causes no visible symptoms in about 90% of the people it infects. As a result, tracking the spread of the polio virus is extremely difficult, which makes it a difficult eradication target. Perhaps most importantly, smallpox patients generally did not reach their highest level of infectivity (that is, their ability to infect others) until after the appearance of the smallpox rash. As a result, quick action to quarantine infected individuals upon the eruption of the rash usually left enough time to vaccinate anyone who had already been exposed, and prevent additional exposures.

Many infectious diseases do not allow for this kind of reaction time. Measles patients, for example, can become infectious up to four days before the appearance of the measles rash. As a result, they can pass the virus on to many, many other people before anyone even knows that they are infected. Many people still think eradication is possible for certain diseases. Efforts are ongoing to eradicate polio and Guinea worm disease (Dracunculiasis), with both having been eliminated in many regions, but remaining endemic in several countries. Meanwhile, the Carter Center International Task Force for Disease Eradication has declared additional diseases as potentially eradicable: lymphatic filariasis (Elephantiasis), mumps, pork tapeworm, and yaws. [3] [For more about this topic, see our article on disease eradication .] Is the polio vaccine linked to HIV? In the 1990s, certain critics began to blame the testing of a live, weakened polio vaccine in Africa in the 1950s for the spread of acquired immune deficiency syndrome (AIDS).

Those behind the accusation argued that chimpanzee cells were used to create the vaccine, and that those cells had been contaminated with a virus that sometimes affects chimps: simian immunodeficiency virus, or SIV. When the vaccine was given to children in Africa, they argued, SIV mutated to become human immunodeficiency virus, or HIV, which causes AIDS. The accusations, however, were demonstrably false for a variety of reasons. Most notably, the weakened polio vaccine was not made with chimpanzee cells, but with monkey cells. The vaccine was later tested using a technique that can detect viral DNA (the PCR technique, or polymerase chain reaction); it did not contain SIV or HIV. Researchers at the University of Birmingham in Alabama demonstrated in 2006 that while HIV was in fact a derivative of SIV, chimpanzees in Cameroon that had been infected with SIV in the 1930s were the most likely source of the AIDS epidemic—decades before the weakened polio vaccine was tested in Africa. top Is the polio vaccine linked with cancer? The polio vaccines developed by Jonas Salk and Albert Sabin in the mid-20th century were made with monkey cells.

Years later, microbiologist Maurice Hilleman found a monkey virus in both vaccines—the 40th monkey virus to be discovered, which he called Simian Virus 40 (SV40). (Salk’s killed vaccine, which had been treated with formaldehyde, had very small amounts of the virus; Sabin’s live vaccine was heavily contaminated.) Worried about the potential effects the virus could have on humans, Hilleman injected it into hamsters, finding that nearly all of them developed massive cancerous tumors. But the initial panic this caused gave way in the face of future studies. First, hamsters that ingested SV40 instead of being injected with it didn’t get cancer. Sabin’s live vaccine (which contained more SV40 than Salk’s) was given orally. Additional studies showed that children who were given Sabin’s vaccine did not develop antibodies to SV40; it simply passed through their digestive system, never causing infection. That left only Salk’s vaccine, which contained very little SV40, but was given by injection.

Studies performed eight years, fifteen years, and thirty years after SV40-contaminated vaccines had been given to children found that they had the same cancer incidence as unvaccinated groups. No credible evidence suggests that SV40 has ever caused cancer in humans. Polio | Vaccines.gov Vaccine Basics Acute flaccid myelitis (AFM) is a rare disease that affects the nervous system. It can result from a number of viral infections. In 2016, there was a slight increase in the number of confirmed cases of AFM. To protect against infections that cause AFM stay up-to-date on recommended vaccinations, including polio vaccine, wash your hands often with soap and water, and protect yourself from mosquito bites. Learn more about AFM. Polio used to be very common in the United States and caused severe illness in thousands of people each year before polio vaccine was introduced in 1955. Most people infected with the polio virus have no symptoms, however for the less than one percent who develop paralysis (cannot move arms or legs) it may result in permanent disability and even death.

There are two types of vaccine that protect against polio: Inactivated Polio Vaccine (IPV) and Oral Polio Vaccine (OPV). IPV, used in the United States since 2000, is given as an injection in the leg or arm, depending on age. OPV is taken by mouth. Polio vaccine may be given at the same time as other vaccines. For Children Most people should get polio vaccine when they are children. Children should be vaccinated with four doses of inactivated polio vaccine (IPV) at the following ages: 1st dose: 2 months Booster dose: 4-6 years For Adults Most adults do not need polio vaccine because they were already vaccinated as children. But three groups of adults are at higher risk and should consider polio vaccination in the following situations: You are traveling to polio-endemic or high-risk areas of the world. Ask your health care provider for specific information on whether you need to be vaccinated. You are working in a laboratory and handling specimens that might contain polioviruses. You are a health care worker treating patients who could have polio or have close contact with a person who could be infected with poliovirus.

Adults in these three groups who have never been vaccinated against polio should get three doses of IPV: 1st dose: Any time 2nd dose: 1 to 2 months after the first dose 3rd dose: 6 to 12 months after the second dose Adults in these three groups who have had one or two doses of polio vaccine in the past should get the remaining one or two doses. It doesn’t matter how long it has been since the earlier dose(s). About Polio What is Polio? Poliomyelitis (polio) is a highly infectious disease caused by a virus that invades the nervous system. Polio is an infectious disease caused by a virus that lives in the throat and intestinal tract. It is most often spread through person-to-person contact with the stool of an infected person and may also be spread through oral/nasal secretions (such as saliva). Less than one percent of polio cases result in permanent paralysis of the limbs (usually the legs). Of those paralyzed, five to ten percent die when the paralysis strikes the respiratory muscles. Paralysis can lead to permanent disability and death. Who gets Polio? Polio, or poliomyelitis, can strike at any age.

The United States has been polio-free since 1979. But poliovirus still occurs in a few countries in Asia and Africa. In the late 1940s to the early 1950s, polio crippled an average of over 35,000 people in the United States each year; it was one of the most feared diseases of the twentieth century. Thanks to the polio vaccine, dedicated health care professionals, and parents who vaccinate their children on schedule, polio has been eliminated in this country for over 30 years. Maintaining the success rate of U.S. vaccination efforts is crucial since the disease still occurs in some parts of the world. People most at risk are those who never had polio vaccine, those who never received all the recommended vaccine doses, and those traveling to areas where polio is still common. Up to 95% of persons infected with polio will have no symptoms. About 4-8% of infected persons have minor symptoms such as: Fever Stiffness in the neck and back Pain in the limbs, which often resolves completely Vaccines: Vac-Gen/Why Are Childhood Vaccines So Important?

ShareCompartir It is always better to prevent a disease than to treat it after it occurs. Diseases that used to be common in this country and around the world, including polio, measles, diphtheria, pertussis (whooping cough), rubella (German measles), mumps, tetanus, rotavirus and Haemophilus influenzae type b (Hib) can now be prevented by vaccination. Thanks to a vaccine, one of the most terrible diseases in history – smallpox – no longer exists outside the laboratory. Over the years vaccines have prevented countless cases of disease and saved millions of lives. Immunity Protects us From Disease Immunity is the body’s way of preventing disease. Children are born with an immune system composed of cells, glands, organs, and fluids located throughout the body. The immune system recognizes germs that enter the body as "foreign invaders” (called antigens) and produces proteins called antibodies to fight them. The first time a child is infected with a specific antigen (say measles virus), the immune system produces antibodies designed to fight it. This takes time . . . usually the immune system can’t work fast enough to prevent the antigen from causing disease, so the child still gets sick.

However, the immune system “remembers” that antigen. If it ever enters the body again, even after many years, the immune system can produce antibodies fast enough to keep it from causing disease a second time. This protection is called immunity . It would be nice if there were a way to give children immunity to a disease without their having to get sick first. In fact there is: Vaccines contain the same antigens (or parts of antigens) that cause diseases. For example, measles vaccine contains measles virus. But the antigens in vaccines are either killed, or weakened to the point that they don’t cause disease. However, they are strong enough to make the immune system produce antibodies that lead to immunity. In other words, a vaccine is a safer substitute for a child’s first exposure to a disease. The child gets protection without having to get sick. Through vaccination, children can develop immunity without suffering from the actual diseases that vaccines prevent. Vaccine Information Statement | Polio | VIS | CDC Polio is also included in the combination vaccine VIS, Your Child’s First Vaccines Polio Vaccine What You Need to Know Why get vaccinated? Vaccination can protect people from polio. Polio is a disease caused by a virus.

It is spread mainly by person-to-person contact. It can also be spread by consuming food or drinks that are contaminated with the feces of an infected person. Most people infected with polio have no symptoms, and many recover without complications. But sometimes people who get polio develop paralysis (cannot move their arms or legs). Polio can result in permanent disability. Polio can also cause death, usually by paralyzing the muscles used for breathing. Polio used to be very common in the United States. It paralyzed and killed thousands of people every year before polio vaccine was introduced in 1955. There is no cure for polio infection, but it can be prevented by vaccination. Polio has been eliminated from the United States. But it still occurs in other parts of the world. It would only take one person infected with polio coming from another country to bring the disease back here if we were not protected by vaccination. If the effort to eliminate the disease from the world is successful, some day we won’t need polio vaccine. Until then, we need to keep getting our children vaccinated. Inactivated Polio Vaccine (IPV) can prevent polio. Children Most people should get IPV when they are children.

Doses of IPV are usually given at 2, 4, 6 to 18 months, and 4 to 6 years of age. The schedule might be different for some children (including those traveling to certain countries and those who receive IPV as part of a combination vaccine). Your health care provider can give you more information. Adults Most adults do not need IPV because they were already vaccinated against polio as children. But some adults are at higher risk and should consider polio vaccination, including: people traveling to certain parts of the world, laboratory workers who might handle polio virus, and health care workers treating patients who could have polio. These higher-risk adults may need 1 to 3 doses of IPV, depending on how many doses they have had in the past. There are no known risks to getting IPV at the same time as other vaccines. Some people should not get this vaccine Tell the person who is giving the vaccine: If the person getting the vaccine has any severe, life-threatening allergies. If you ever had a life-threatening allergic reaction after a dose of IPV, or have a severe allergy to any part of this vaccine, you may be advised not to get vaccinated. Ask your health care provider if you want information about vaccine components.

If the person getting the vaccine is not feeling well. If you have a mild illness, such as a cold, you can probably get the vaccine today. If you are moderately or severely ill, you should probably wait until you recover. Your doctor can advise you. Top of Page Risks of a vaccine reaction With any medicine, including vaccines, there is a chance of side effects. These are usually mild and go away on their own, but serious reactions are also possible. Some people who get IPV get a sore spot where the shot was given. IPV has not been known to cause serious problems, and most people do not have any problems with it. Other problems that could happen after this vaccine: People sometimes faint after a medical procedure, including vaccination. Sitting or lying down for about 15 minutes can help prevent fainting and injuries caused by a fall. Tell your provider if you feel dizzy, or have vision changes or ringing in the ears. Some people get shoulder pain that can be more severe and longer-lasting than the more routine soreness that can follow injections. This happens very rarely. Any medication can cause a severe allergic reaction.

Such reactions from a vaccine are very rare, estimated at about 1 in a million doses, and would happen within a few minutes to a few hours after the vaccination. As with any medicine, there is a very remote chance of a vaccine causing a serious injury or death. The safety of vaccines is always being monitored. For more information, visit the vaccine safety site. What if there is a serious reaction? What should I look for? Look for anything that concerns you, such as signs of a severe allergic reaction, very high fever, or unusual behavior. Signs of a severe allergic reaction can include hives, swelling of the face and throat, difficulty breathing, a fast heartbeat, dizziness, and weakness. These would usually start a few minutes to a few hours after the vaccination. What should I do? If you think it is a severe allergic reaction or other emergency that can’t wait, call 9-1-1 or get to the nearest hospital. Otherwise, call your clinic. Afterward, the reaction should be reported to the Vaccine Adverse Event Reporting System (VAERS).

Your doctor should file this report, or you can do it yourself through the VAERS website , or by calling 1-800-822-7967. VAERS does not give medical advice. Top of Page The National Vaccine Injury Compensation Program The National Vaccine Injury Compensation Program (VICP) is a federal program that was created to compensate people who may have been injured by certain vaccines. Persons who believe they may have been injured by a vaccine can learn about the program and about filing a claim by calling 1-800-338-2382 or visiting the VICP website . There is a time limit to file a claim for compensation. Top of Page How can I learn more? Ask your healthcare provider. He or she can give you the vaccine package insert or suggest other sources of information. Contact the Centers for Disease Control and Prevention (CDC): Call 1-800-232-4636 (1-800-CDC-INFO) or OPV – GPEI OPV Oral poliovirus vaccine The oral polio vaccine is simple to administer. A few drops, given multiple times, can protect a child for life.

© WHO/Rod Curtis Oral poliovirus vaccines (OPV) are the predominant vaccine used in the fight to eradicate polio. There are different types of oral poliovirus vaccine, which may contain one, a combination of two, or all three different serotypes of attenuated vaccine. Each has their own advantages and disadvantages over the others. The attenuated poliovirus(es) contained in OPV are able to replicate effectively in the intestine, but around 10,000 times less able to enter the central nervous system than the wild virus. This enables individuals to mount an immune response against the virus. Virtually all countries which have eradicated polio used OPV to interrupt person to person transmission of the virus. Advantages OPVs are all inexpensive (US $0.12-$0.18 for countries procuring through UNICEF in 2016). OPVs are safe and effective and offer long lasting protection against the serotype(s) which they target. OPV stimulates good mucosal immunity, which is why it is so effective at interrupting transmission of the virus. OPVs are administered orally and do not require health professionals or sterile needle syringes.

As such, OPVs are easy to administer in mass vaccination campaigns. For several weeks after vaccination the vaccine virus replicates in the intestine, is excreted and can be spread to others in close contact. This means that in areas with poor hygiene and sanitation, immunization with OPV can result in ‘passive’ immunization of people who have not been vaccinated. Disadvantages OPV is extremely safe and effective. However, in extremely rare cases (approx. 1 in every 2.7 million first doses of the vaccine) the live attenuated vaccine-virus in OPV can cause paralysis. In some cases, it is believed that this may be triggered by an immunodeficiency. The extremely low risk of vaccine-associated paralytic poliomyelitis (VAPP) is well accepted by most public health programmes. Very rarely, when there is insufficient coverage in a community the vaccine-virus may be able to circulate, mutate and, over the course of 12 to 18 months, reacquire neurovirulence. This is known as a circulating vaccine-derived poliovirus.

WHO position statement: safety and pre-qualification of oral polio vaccine (OPV) Monovalent oral poliovirus vaccine (mOPV) Prior to the development of tOPV, monovalent OPVs (mOPVs) were developed in the early 1950s, but largely dropped out of use upon the adoption of tOPV. It was not available at the time of the founding of GPEI in 1988. Monovalent oral polio vaccines confer immunity to just one of the three serotypes of OPV. They are more successful in conferring immunity to the serotype targeted than tOPV, but do not provide protection to the other two types. Monovalent OPVs for type 1 (mOPV1) and type 3 (mOPV3) poliovirus were licensed again in 2005, thanks to successful action taken by the GPEI. They elicit the best immune response against the serotype they target of all the vaccines. Monovalent OPV type 2 (mOPV2) has been stockpiled in the event of a cVDPV2 outbreak.

Bivalent oral poliovirus vaccine (bOPV) Following April 2016, the trivalent oral poliovirus vaccine was replaced with the bivalent oral poliovirus vaccine (bOPV) in routine immunization around the world. Bivalent OPV contains only attenuated virus of serotypes 1 and 3, in the same number as in the trivalent vaccine. Bivalent OPV elicits a better immune response against poliovirus types 1 and 3 than trivalent OPV, but does not give immunity against serotype 2. As well as in routine immunization, bOPV will be used for outbreak response against poliovirus types 1 and 3 outbreaks. Trivalent oral poliovirus vaccine (tOPV) Prior to April 2016, the trivalent oral poliovirus vaccine (tOPV) was the predominant vaccine used for routine immunization against poliovirus. Developed in the 1950s by Albert Sabin, tOPV consists of a mixture of live, attenuated polioviruses of all three serotypes.

Also called the ‘Sabin vaccine’, tOPV is inexpensive and effective, and offers long lasting protection to all three serotypes of poliovirus. The trivalent vaccine was withdrawn in April 2016 and replaced with the bivalent oral poliovirus vaccine (bOPV), which contains only attenuated virus of types 1 and 3. This is because continued use of tOPV threatened to continue seeding new type 2 circulating vaccine-derived polioviruses (cVDPV2), despite the wild type 2 virus being eradicated in 1999. Also in Slate: Jonas Salk didn’t patent the polio vaccine, but Google Doodles—like today’s on Salk—are patented . On April 12, 1955, Edward R. Murrow asked Jonas Salk who owned the patent to the polio vaccine. “Well, the people, I would say,” Salk responded. “There is no patent. Could you patent the sun ?” By the time of his chat with Murrow, which aired on the day the polio vaccine was announced as safe and 90 percent effective, Salk was already more messiah than virologist to the average American.

Polio paralyzed between 13,000 and 20,000 children annually in the last pre-vaccine years, and Salk was the face of the inoculation initiative. Appearing on television to present the vaccine as a gift to the American people was a public relations masterstroke. Advertisement Over the last half-century, Salk’s rhetorical question to Murrow has become a rallying cry for those who campaign against pharmaceutical company profiteering. To many, it represents a generous view of scientific discovery distilled down to a beautiful simplicity. One critic of the big pharma called Salk “the foster parent of children around the world with no thought of the money he could make by withholding the vaccine from the children of the poor.” Get Slate in your inbox. In fact, Salk’s three-sentence response to Murrow is a dangerous intuition pump —a misdirection from complex questions. It represents an easy but wrongheaded way to avoid the messy work of constructing a system to incentivize medical breakthroughs and make them widely available in the context of 21st-century economic realities. That’s not to say Salk was a propagandist or a panderer—he probably meant every word he said.

But his thoughts on the polio vaccine applied to a specific situation at a specific time in our history. It helps to break Salk’s famous quote into two distinct claims: First, he argued that the polio vaccine belonged to the people. Second, he posed the rhetorical question comparing a vaccine to the sun. The first claim is nearly indisputable as it applies to the polio vaccine itself, because the public voluntarily funded the vaccine’s incredibly expensive research and field testing. Advertisement “People worked on the polio vaccine like it was the Normandy invasion,” says Jane Smith, author of the book Patenting the Sun: Polio and the Salk Vaccine . More than 650,000 children were vaccinated. Their doctors had to submit forms, and public health officials tracked the information. Then it all had to happen again for placebo and control groups. In the single year that the polio vaccine was unveiled, 80 million people donated money to the National Foundation for Infantile Paralysis, which spearheaded the vaccine effort. Many donors could only afford a few cents, but gave anyway (hence the foundation’s modern name, the March of Dimes).

Schools, communities, and companies joined in a remarkable display of unity against the disease. Even Walt Disney’s cartoon characters contributed their talents, appearing in a film that adapted the Snow White and the Seven Dwarfs’ song “Heigh Ho” to an anti-polio ditty. In the 13 years leading up to the vaccine’s roll out, the budget of the National Foundation for Infantile Paralysis swelled from $3 million to $50 million. An entire generation of microbiologists received money from the foundation, which even played a role in Watson and Crick’s description of DNA . There was near unanimity within the organization that the public had already paid for the polio vaccine through their donations, and patenting it for profit would have represented double charging. That’s what Jonas Salk should have said to Murrow—not that all vaccines belong to the people, but rather that this vaccine belonged to the people. There is an important footnote regarding Salk’s statement that “there is no patent.” Prior to Murrow’s interview with Salk, lawyers for the National Foundation for Infantile Paralysis did look into the possibility of patenting the vaccine, according to documents that Jane Smith uncovered during her dive into the organization’s archives.

The attorneys concluded that the vaccine didn’t meet the novelty requirements for a patent, and the application would fail. This legal analysis is sometimes used to suggest that Salk was being somewhat dishonest —there was no patent only because he and the foundation couldn’t get one. That’s unfair. Before deciding to forgo a patent application, the organization had already committed to give the formulation and production processes for the vaccine to several pharmaceutical companies for free. No one knows why the lawyers considered a patent application, but it seems likely that they would only have used it to prevent companies from making unlicensed, low-quality versions of the vaccine. There is no indication that the foundation intended to profit from a patent on the polio vaccine. Advertisement The decision not to patent the vaccine made perfect economic sense under the circumstances. “The National Foundation for Infantile Paralysis was a nonprofit, centralized research and development operation,” says Robert Cook-Deegan, who studies intellectual property and genomics at Duke University. “They didn’t need an incentive structure.” Newspaper headlines celebrate the success of the polio vaccine. Photo courtesy March of Dimes/Wikimedia Commons That brings us to Salk’s grand question: Can you patent the sun?

When you unpack this query, which is really a policy argument, you find two assumptions. Most obviously, Salk assumed that a vaccine is a naturally occurring phenomenon rather than a human invention. In addition, and perhaps more importantly, he implies that this distinction should be central in patent law. Both of these points are debatable. Whether a vaccine should be viewed as a naturally occurring substance, rather than a product of human engineering, may depend on the details of the individual inoculation. In 1796, Edward Jenner immunized an 8-year-old boy against smallpox by injecting him with pus from a milk maid who had been exposed to cowpox, a related disease. (The word vaccine comes from vaccinia, the Latin name for cowpox.) While ingenious, moving pus from one person to another would not entitle Jenner to a patent in modern America. Few modern vaccines are that simple, though. Some still contain live or dead cells from the pathogen itself, but others contain genetically modified versions of the virus or bacteria. Some rely on one or more proteins from the pathogen, or a part of a protein that’s sufficient to trigger an immune response.

The flu vaccine, which has to be made anew every year, involves months of work by highly trained scientists working in state-of-the-art laboratories. It’s a stretch to describe modern vaccines as naturally occurring, even if parts of them are. Although the U.S. government has issued thousands of patents related to vaccines, American jurisprudence is still in a state of confusion on this issue. The Patent Act of 1952, which established the current structure of patent law, did not recognize a difference between inventions and discoveries. When that distinction came from the Supreme Court in 1980, the court made clear that “ products of nature ”—like the sun, as Salk might say—are not patentable. Isolating and purifying a product, however, may render it patentable under the right conditions. Advertisement Should the Supreme Court ever get around to clarifying the patentability of vaccines, it may consider revisiting the distinction between discovery and invention, because it misses the point of intellectual property law: to incentivize research that will benefit humanity. Even if a vaccine is a product of nature, discovering that product and making it useful is absolutely nothing like discovering the sun and putting it to work.

(Most living creatures have managed that trick on a daily basis for billions of years.) Since Jenner, few microbiologists have stumbled upon effective vaccines. Without the promise of exclusive marketing rights for some period, no profit-minded private entity would undertake the necessary research. The landscape has shifted since Salk’s heyday. The U.S. government is now the primary applicant for vaccine-related patents, followed by GlaxoSmithKline and a number of other corporations. Private groups, like the Pasteur Institute, are also active. Responsibility for vaccine development is more evenly distributed now than in the 1950s, and that’s a good thing. Top Comment

Question: What does the Salk vaccine protect against
Answer: Polio