Polio

Scientific studies (review articles) on polio:
One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of randomized, placebo-controlled double blind clinical trials (RCTs) will answer the following question:
"Do taking dietary supplements make sense?" Yes for a positive conclusion and no for a negative conclusion.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of (prospective) cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

1. No difference in seroconversion between 3 doses of fIPV and 3 doses of full-dose poliovirus vaccine
2. Sequential polio vaccination schedule gives stronger immunogenicity
3. Maternal antibody concentrations and infant age at first vaccination both influence infant vaccine responses
4. One IPV dose should be added to protect against paralysis caused by type 2 poliovirus

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• Polio is the common name for poliomyelitis, which comes from the Greek words for grey and marrow, referring to the spinal cord and the suffix -itis, meaning inflammation.
• Poliovirus, the causative agent of polio, is a member virus of Enterovirus C, in the family of Picornaviridae.
• Poliovirus was first isolated in 1909 by Karl Landsteiner and Erwin Popper.
• Poliovirus is one of the most well-characterized viruses and has become a useful model system for understanding the biology of RNA viruses.
• The time between first exposure and first symptoms of polio, known as the incubation period, is usually 6 to 20 days, with a maximum range of 3 to 35 days.
• Initial symptoms of polio include fever, fatigue, headache, vomiting, stiffness in the neck and pain in the limbs. In a small proportion of cases, the disease causes paralysis, which is often permanent.
• There are 3 wild types of poliovirus (WPV):
  1. Type 1
  2. Type 2
  3. Type 3
• These 3 polio viruses spread through contact between people, by nasal and oral secretions and by contact with contaminated feces.
• Poliovirus enters the body through the mouth, multiplying along the way to the digestive tract, where it further multiplies.
• Most infected people (90%) have no symptoms or very mild symptoms and usually go unrecognized.
  Fewer than 1%-2% of people who contract polio become paralyzed.
• People need to be protected against all 3 types of the virus in order to prevent polio disease and the polio vaccination is the best protection.
• There is no cure for polio. However, the disease is preventable with the polio vaccine. But, multiple doses are required for it to be effective.
• There are 2 types of vaccines used to protect against polio disease, oral polio vaccine and inactivated poliovirus vaccine.
  The first polio vaccine was developed in 1955.
• The oral polio vaccine (OPV) is used in many countries to protect against polio disease and has been essential to the eradication effort.
  People who receive oral polio vaccine may shed the virus and can infect others, especially those who are not vaccinated. In areas with low vaccination rates, the oral polio vaccine virus can continue to infect new individuals. In rare cases, the oral polio vaccine virus can accumulate changes over time and become like wild poliovirus (WPV). These new viruses are called vaccine-derived polioviruses (VDPV) and can cause polio disease.
• After wild poliovirus type 2 was declared eradicated in 2015, the world switched from trivalent to bivalent oral polio vaccine. Trivalent oral polio vaccine contains all 3 types of poliovirus, while bivalent OPV only contains poliovirus type 1 and 3. This switch means that oral polio vaccine no longer protects against WPV2.
• Inactivated poliovirus vaccine (IPV) protects people against all 3 types of poliovirus. Inactivated poliovirus vaccine does not contain live virus, so people who receive this vaccine do not shed the virus and cannot infect others and the vaccine cannot cause disease. Countries that use bOPV have added a single dose of IPV to protect against WPV2.
• Inactivated poliovirus vaccine is given as an injection in the leg or arm, depending on the patient's age. Polio vaccine may be given at the same time as other vaccines.
• Polio mainly affects children under the age of 5.
• Most people should get polio vaccine when they are children. Children get 4 doses of inactivated poliovirus vaccine at these ages: 2 months, 4 months, 6-18 months and a booster dose at 4-6 years.
• There are 6 different vaccines to stop polio transmission:
  • Inactivated polio vaccine (IPV) - protects against poliovirus types 1, 2 and 3.
  • Trivalent oral polio vaccine (tOPV) - protects against poliovirus types 1, 2 and 3 - following the "OPV Switch" in April 2016, tOPV is no longer in use.
  • Bivalent oral polio vaccine (bOPV) - protects against poliovirus types 1 and 3.
  • Monovalent oral polio vaccines (mOPV1, mOPV2 and mOPV3) - protect against each individual type of poliovirus, respectively.
• Because of widespread vaccination, polio was eliminated from the Western Hemisphere in 1994.
  Today, polio remains endemic in 3 countries - Afghanistan, Nigeria and Pakistan.
• The Global Polio Eradication Initiative is a public-private partnership led by national governments with 5 core partners - the World Health Organization (WHO), Rotary International, the US Centers for Disease Control and Prevention (CDC), the United Nations Children’s Fund (UNICEF) and the Bill & Melinda Gates Foundation. Its goal is to eradicate polio worldwide.
• Bill Gates believes in a world without polio.
  When the Gates Foundation launched the Global Polio Eradication Initiative, in 1988, there were 350,000 cases of polio reported globally. In 2018 there were 31.
• Polio cases are reduced by 99.9% since 1988. More than 16 million people have been saved from paralysis because of vaccination efforts against polio.
• Every child must be vaccinated to eradicate polio.