Poliomyelitis vaccine

Poliomyelitis vaccine is a vaccine used to prevent poliomyelitis (polio), a highly contagious viral infection that can lead to paralysis and even death. The disease primarily affects children under five years old, making vaccination an essential public health strategy. There are two main types of polio vaccines: the inactivated poliovirus vaccine (IPV) and the oral poliovirus vaccine (OPV).

Types of Polio Vaccines

Inactivated Poliovirus Vaccine (IPV)

The IPV, developed by Jonas Salk in the 1950s, contains inactivated (killed) poliovirus. It is administered via injection. IPV is safe and effective, providing immunity to all three types of poliovirus. Since the vaccine is inactivated, it cannot cause polio. It is the only polio vaccine that is used in the United States since 2000 due to its safety profile.

Oral Poliovirus Vaccine (OPV)

The OPV, developed by Albert Sabin and first licensed in 1961, contains a weakened form of the virus. It is administered orally. OPV is highly effective and inexpensive, making it the vaccine of choice in many countries, especially for mass vaccination campaigns. However, in very rare cases, OPV can cause vaccine-associated paralytic poliomyelitis (VAPP) or can mutate into a form that can cause outbreaks of polio.

Vaccination Schedule

The World Health Organization (WHO) recommends that polio vaccination should be included in the national immunization schedules worldwide. The recommended schedule for IPV is four doses, given at two months, four months, between six and 18 months, and a booster dose at four to six years of age. The OPV is often given in multiple doses, with the exact schedule varying by country.

Global Polio Eradication Initiative

The Global Polio Eradication Initiative (GPEI), launched in 1988 by the WHO, UNICEF, Rotary International, and the CDC, aims to eradicate polio worldwide. Through mass vaccination campaigns and surveillance, the initiative has significantly reduced polio cases by over 99% since its inception. Only two countries, Afghanistan and Pakistan, continue to report cases of wild poliovirus as of the last update.

Safety and Side Effects

Both IPV and OPV are generally safe and well-tolerated. The most common side effects are mild and include soreness at the injection site for IPV and mild gastrointestinal disturbances for OPV. Severe side effects are extremely rare but can include allergic reactions to components of the vaccine.

Conclusion

The poliomyelitis vaccine is a cornerstone of global public health efforts to eradicate polio. Both IPV and OPV have played critical roles in reducing the incidence of this debilitating disease. Continued vaccination efforts, especially in areas where polio remains endemic, are essential to achieving a polio-free world.