One fine sunny morning, Felix had a niggling doubt. So, he asked Verum, “Is it necessary to take the polio vaccine even today?”
Verum smiled and said, “Yes, it is necessary. 
Recently, a young adult in Rockland County in New York, the United States (US), contracted polio. The unnamed patient became the first person to contract this deadly disease in 10 years. They are no longer contagious but they have developed paralysis due to the infection. 
Paralysis is a condition in which a person loses mobility and at times, sensation. It can occur in a part or whole of the body. Paralysis can be caused by illness, injury, or poison.
Polio is one such illness that can lead to paralysis. It mostly spreads through the feces of patients and affects children younger than five years old. Some people show no symptoms while others only show flu-like symptoms. But in about one in a hundred or one in a thousand patients, the infection attacks the nerves in the brain and spinal cord. This can cause paralysis. It isn’t usually permanent but there are times when it can be.” 
“Oh, that is a concern,” remarked Scorch, “But it is only one case! I am sure there’s not much cause for worry.”
“Dr. Patricia Schnabel Ruppert, the health commissioner for Rockland County, is certainly worried. The incidents of paralytic polio are 1%,” said Verum, “So, if a patient has developed paralytic polio, it means there are more undetected cases of polio.”
“Had the patient been vaccinated against polio?” said Orak.
“No. But they probably contracted it from a vaccinated person,” said Verum, “Before you get alarmed, let me explain. In most developed countries like the US, the polio vaccine is made of an inactivated form of the virus. But some developing countries use a weakened form of the virus as a vaccine. 
In rare cases, this virus may mutate and cause a fresh outbreak. This will be bad news because polio is a serious illness. It has been eradicated in many parts of the world through rigorous vaccination. As of now, wild poliovirus is only found in Pakistan and Afghanistan.”
“I suppose the ideal plan of action is increasing vaccination,” said Orak. Verum nodded in agreement.