It seemed to be behind us. What factors are influencing the return of the polio virus? A few weeks ago, in the US, it was reported that a man was paralyzed by the virus. Israel reported the same a few months ago. What is happening?
In New York City the case was that of a man who is not vaccinated. But it may be the tip of the iceberg. Unvaccinated people could wake up the disease.

Old virus
Poliomyelitis is an ancient disease caused by three strains of poliovirus. Perhaps the earliest depiction is an Egyptian burial tablet from around 1400 B.C. It was first clinically described in 1789. The virus is spread primarily through contact with the feces of an infected person. It is famous for causing severe paralysis. However, paralytic poliomyelitis is rare. One in 200 people develop paralysis.
But until the vaccine was developed, there were 16,000 cases a year in the United States. Salk’s vaccine changed that radically. A massive immunization campaign caused it to be eliminated almost worldwide. It could be alarming that cases continue to appear.
In New York, campaigns are started to remind people of the importance of vaccinating children. The Department of Health is in charge of this. The COVID-19 pandemic has disrupted routine childhood immunization worldwide. In the United Kingdom, public health officials have launched a vaccination campaign.
The problem is communities that have so far refused to vaccinate their children. Many parents choose not to vaccinate their children because they do not understand the risks of polio. It is the same with other childhood diseases such as measles.

Oral vaccines
An oral vaccine developed after Salk’s, by Albert Sabin, is used in many places. But the slightest chance that this type of vaccine will lead to disease. Oral vaccines will have to be abandoned, even though they were once essential for global eradication. Because it was administered in drops, it was easier to transport to remote places.
Be that as it may, the return of the poliovirus is a warning sign. In the past, the vaccine eradicated it almost 100%. It is inconceivable that, despite this, its efficacy is still in doubt. That is the main risk now.