Polio - also known as poliomyelitis - is a highly contagious viral disease. Often, no specific symptoms occur. In severe cases, it can lead to paralysis of the legs or the respiratory muscles as a result of the disease. Polio has been eradicated in Europe since 2002, yet two cases occurred in Ukraine in September 2015. This makes it clear how important a vaccine is to prevent a recurrence of the virus disease. Until 1998, two different vaccines against polio were available. Today, only the IPV vaccine developed by Jonas Salk, which is injected intramuscularly, is used. The oral vaccine, on the other hand, is no longer used in Germany, since it rarely causes polio itself.
What is polio?
Polio is a disease caused by the highly contagious poliovirus. Anyone who has been infected with the virus can be contagious for just a few hours after the infection and stay there for up to six weeks. How long it takes for the disease to break out can vary considerably: the incubation period is usually between three and 35 days.
The virus is predominantly transmitted fecally-orally. In this regard, polioviruses are similar to those causing hepatitis A. Fecal-oral means that the pathogen is eliminated by infected people with the stool. Due to a lack of hygiene, the viruses can then reach objects or liquids and be taken up in this way via the mouth (orally). A droplet infection by sneezing or coughing is possible, but relatively rare.
Polio: Symptoms nonspecific
Polio is often either completely without or at least without clear symptoms. The affected then usually do not notice that they are infected with the virus. They are characterized by nonspecific symptoms such as fever, sore throat, loss of appetite, nausea and diarrhea. This phase can last for between one and two weeks - in many cases, the disease then subsides.
If the viruses invade the central nervous system, symptoms such as fever, back pain, neck stiffness and muscle pain may occur about three to seven days after the end of the first phase. In some individuals - estimated to be between 0.1 and 1 percent - subsequently the polio typical paralysis. These are asymmetric paralyzes, which usually remain after the disease has resolved.
The paralyzes are primarily affecting the legs. The virus can also affect other muscles, for example in the arms, eyes or in the stomach. If the paralysis expands on the respiratory muscles, this can lead to the death of the patient. Severe disease is more likely in adult patients than in children.
After a polio disease has survived, the so-called post-polio syndrome can occur in the further course of life, sometimes only years or decades later. This syndrome can also be felt when the polio disease itself has gone away without any symptoms.
In the course of post-polio syndrome symptoms such as muscle atrophy, weakness, pain and fatigue occur. It is typical that during medical examinations no causes for the complaints can be found. It is therefore thought that in some chronic diseases without apparent cause post polio syndrome is behind the complaints.
A treatment against the polioviruses is not possible, because so far there are no drugs with which one can fight the pathogens. If the disease has broken out, only the symptoms can be treated. The only effective protection against polio is polio vaccination.
Vaccination protects against polio
To protect against polio, two different vaccinations were available in Germany until 1998:
- Oral vaccine (oral polio vaccine, OPV)
- Injection (injectable polio vaccine, IPV according to Salk)
Since 1998, only the IPV vaccine has been used in Germany. Although the oral vaccine administered with weakened polioviruses provided more effective protection, in rare cases it even caused polio. Every year, about one or two such cases occurred in Germany (poliomyelitis vaccine).
Today, therefore, only the IPV vaccine is used. This can not cause poliomyelitis, since no attenuated, but killed viruses are injected. The vaccine is injected either in the buttocks, upper arm or thigh.
A disadvantage of this form of vaccination is that it is more complex and associated with more costs. This makes it difficult, especially in developing countries, to achieve nationwide vaccination coverage. Here, the oral vaccine is still often used.
Polio - How often do you vaccinate?
How often you need to be vaccinated against polio depends on the type of vaccine you are using - whether a single or combination vaccine is used. As a rule, the vaccinations are carried out at the age of two, three and four months and between the eleventh and the fortieth month. The polio vaccination is often done together with the vaccinations against tetanus, diphtheria and whooping cough. Between the ages of 9 and 17, a booster dose is recommended.
If, after looking through your vaccination certificate, you discover that you have not had all the necessary polio vaccinations, you should contact your GP and have the vaccinations collected.
Polio goes back worldwide
Polio used to be distributed worldwide and was relatively common. However, by the introduction of the oral vaccine in 1962, the disease was almost completely suppressed. Large parts of the world are now considered polio-free.
Some parents believe there is no risk and do not have their children vaccinated against polio. However, this is a dangerous fallacy. Because the lack of vaccine protection increases the risk that in Germany again polio cases occur. Although no cases were reported in Germany in recent years, in 2015 polio cases recurred in Europe.