Professor Zachi Grossman, chairman of the Israel Pediatric Association, on Monday morning responded to the news that for the first time since 1989, a child in Israel was diagnosed with polio.
Speaking to 103 FM Radio, Prof. Grossman said, "What happened here is a rare occurrence. This happens because the virus we use for vaccination is a live attenuated virus which is given in droplets."
"In very rare cases, the virus may turn from live attenuated to live virulent, and attack children who for some reason were not vaccinated. They have no layer of protection and the moment they are faced with a virus like this, it is as if they were confronted with a virulent virus and there had never been such a thing as vaccines."
The polio vaccine is given in two forms: the oral polio vaccine (OPV), which is live attenuated, administered as oral droplets, and protects against types 1 and 3; and the inactivated polio vaccine (IPV), which is administered as an injection and which protects against all three types of polio, but requires a series of at least three doses in order to provide protection. Most developed countries use only the IPV, but Israel several years ago reinstated the OPV, administered in addition to the IPV.
When asked whether a child who received the live attenuated vaccine might be responsible for the unvaccinated child's infection, Prof. Grossman said, "It's true. The live attenuated vaccine is absorbed in the digestive system and excreted by means of secretions. It can, by whatever means, reach another child by means of food or water. If a child is protected as he should be by means of the various vaccines, then nothing will happen to him if he is confronted with the virus."
In Prof. Grossman's eyes, the fact that a case of polio was discovered after 30 years of no cases is not the worrying part of the story.
"What is very worrying is that there is no treatment for polio - it's not even coronavirus. The moment the tissues have suffered paralysis and neurological damage, there is no other solution. The importance of the vaccine specifically for polio is greater than it is for other illnesses which have treatments, but here there are no treatments."
Noting Israel's high vaccination rate and the faith parents have in the routine childhood vaccines, Prof. Grossman added, "In 2013 there was an incidence of polio in the sewage and because they found virulent polio viruses there was a nationwide vaccination campaign. Polio is here, and it is not an illness which was eradicated."
"The Health Ministry is conducting an epidemiological investigation for the purpose of identifying where the...virus came from, and investigating contacts, family members. They are also checking fecal excretions of the children themselves, because today the proper scientific way is to check excretions. The virus is going around there and I assume that the fecal samples of everyone who was in close contact will be examined. We can find the virus and genetically sequence it, and see if it is identical to the child's virus.
"The chance of an outbreak is not high, for the same reason that we assume that a great majority of the population are vaccinated against polio. I do not estimate that from this there will be an outbreak. The number of those vaccinated is greater than for coronavirus, especially among children. The vaccine provides full protection against the existing strains. Today the live attenuated vaccine is against two [strains] instead of three, and in very very rare cases someone is infected."