Polio: what is it, symptoms and vaccine

Poliomyelitis, also called polio, or Poliomyelitisis an infectious disease caused by one of the 3 types of polioviruses (serotypes 1, 2, 3). It mainly affects children under the age of 4, but can also occur in adults.

The best form of prevention Children under 5 years of age receive 5 doses of vaccine per day. Thanks to a massive vaccination campaign, Brazil has been free of cases since 1989.

The most common mode of transmission of the virus is the fecal-oral route, that is, oral contact with objects, food and water contaminated with the feces of patients or carriers. Although less common, transmission can also occur through mouth-to-mouth droplets of saliva when talking, coughing or sneezing.

Why does the polio virus cause paralysis?

Symptoms vary depending on the form of the disease and the parts of the body affected by the infection. At first, the virus multiplies in the throat and intestines, developing the non-paralyzed form of the disease.

Symptoms in this case may be fever, nausea, vomiting, constipation (constipation), diarrhea and pain in the throat, body and abdomen.

When gravity increases polio virus enters the bloodstream and is transported to the brain. When it affects the nervous system, the disease can attack the meninges (the membranes that protect the central nervous system) and cause viral meningitis.

In addition, the virus can infect motor neurons, which development of the paralytic form of the diseasebecause one of the main functions of motor neurons is to carry nerve impulses to the muscles so that they can perform movements correctly.

When infected by the polio virus, these cells die and stop performing their role in controlling muscle movements. If dead neurons are responsible for controlling the lower limbs, the result will be paralysis of one of the legs.

If the virus attacks the cells that control the respiratory or swallowing muscles, it can lead to death.

What is the age to get the polio vaccine?

There is still no cure for polio, meningitis, or stroke. Treatment is done to relieve symptoms. Although personal hygiene is one way to prevent contamination, the most important form of protection is vaccination.

That’s why it’s so important All children under 4 are vaccinated. Vaccination schedule for poliomyelitis There are 5 doses of 2 different vaccines. See below.

• 3 doses injectable vaccine against poliomyelitis (VIP) — carrying inactivated (or “dead”) virus:
  • 1st injectable dose: at 2 months;
  • 2nd injectable dose: at 4 months;
  • 3. Injectable dose: at 6 months.
• 2 doses oral polio vaccine (VOP) — in live, attenuated form that cannot cause paralysis:
  • 1st boost dose: 15 months;
  • 2nd booster dose: 4 years.

despite the polio It was eradicated in Brazil and the Americas in the 1990s, with vaccination coverage below 95%, while Brazil is at risk of returning the disease. Currently, less than 70% of infants under 1 year have received the first 3 doses.

Who can get vaccinated polio?

The low rate of vaccinated children makes the country susceptible to the virus from countries where the disease is still freely circulating. Additionally, children missing the schedule run the risk of getting their vaccine doses in the wrong order.

Children who are not properly vaccinated with the inactive form of the virus (VIP) while receiving OPV (which contains a viable, weak form of the virus) may release viral particles in their stools that pose a risk of contamination for unvaccinated individuals.

The free circulation of the poliovirus allows it to mutate, change itself, and eventually cause paralysis again. In this way, reduction in the number of people at risk vaccinated not only individual children, but also all Brazilians.

poliomyelitis It was once one of the world’s most feared childhood diseases. Known since the 19th century, today it is almost destroyed on the planet. With the increase in vaccination efforts and the proliferation of campaigns, we can put an end to this chapter in our children’s history once and for all in the years to come.