Anti-vaxxers keep polio alive

Poliomyelitis or polio is a viral infectious disease which is spread from person to person usually via fecal-to-oral route. Most of the infections produce no symptoms, but in about 1% of the cases the virus causes flaccid paralysis. Muscles can become so weakened that an infected individual may be unable to breathe on their own and must be placed in an iron lung. 1% may not seem like much, but polio virus spreads easily and can infect large number of people.

Polio was very rare before industrialization because the absence of proper sanitation meant that children would be exposed to the virus from fecal matter in very young age and most of them developed the immunity. This was a kind of natural vaccination. Polio became widespread threat in the first half of 20th century. Fortunately in 1950s two kinds of vaccine were developed.

Inactivated polio vaccine (IPV) contains dead virus which cannot lead to infection. It is given by injection into the muscle tissue. Vaccinated individual is cannot develop poliomyelitis, but can still carry polio virus in his/her gut flora and therefore can spread it. Oral polio vaccine (OPV) is designed to immunize recipients gut against polio virus and it stops the spread of the virus completely. It contains weakened form of virus, which unfortunately can lead to paralysis in 1:2 700 000 cases. So, the side effect is very rare and it is certainly better than the odds of 1:200 for developing paralysis in the case of real infection. The small risk of developing vaccine-associated polio paralysis (VAPP) can be circumvented if IPV is administered before OPV.

This kind of regimen eliminated polio from Israel in 1990s, but unfortunately, in 2005 the OPV vaccine was dropped and in 2013 polio virus was once again being detected in sewers all over Israel. Children of up to 9 years old were carriers of the virus. This meant that individuals with weakened or compromised immune systems were are risk of being infected. HIV patients, people with auto-immune diseases or transplanted organs, elderly and babies were all at risk.

The solution to this problem was quite straight forward - administer OPV to all the children born after 2005. There was no risk of VAPP since they all have received IPV. It would have been effective had it not been for the human ignorance. After the start of campaign anti-vaccine activist, mostly from US began their mission of spreading fear, lies and ignorance. Freedom of speech is one of our most sacred rights, but when a group of uneducated and not very smart people set their minds on something the results can be devastating.

In the end, after fierce online battles between anti-vaxxers and people who actually use their brains, 60% of children in Israel received OPV. The result if far from perfect, but it greatly reduced the number of carriers. You can read more about it here.

To me personally it is amazing how such stupid, unreasonable ideas get spread and how certain people can disregard science, logic and common sense and come up with ridiculous pseudoscience and conspiracy theories. Einstein was right, human ignorance is really endless.