TYPES OF VACCINATION [POLIO]

POLIO VACCINATION

The Polio Vaccination is the most popular kind of Routine Immunization. This vaccination is given to children during the early stages of their life, that is from 0 to 5 years.

So before we get into details about this vaccination lets try and understand why is this vaccination important.

UNDERSTANDING THE DISEASE {POLIO}

Polio is caused by intestinal viruses that spread from person to person in stool and saliva. Most people infected with polio (approximately 95%) show no symptoms. Minor symptoms can include sore throat, low-grade fever, nausea, and vomiting. Some infected persons (1 to 2%) will have stiffness in the neck, back, or legs without paralysis. Less than 1% of polio infections (about 1 of every 1,000 cases) cause paralysis. In some cases, the poliovirus will paralyze the muscles used to breathe, leaving the victim unable to breathe on his or her own. Many paralyzed persons recover completely. Those who do recover from paralytic polio may be affected 30 to 40 years later, with muscle pain and progressive weakness.

Before the polio vaccine, 13,000 to 20,000 people were paralyzed by polio, and about 1,000 people died from it each year in the United States. Most of those infected were elementary school children so it was often called ‘infantile paralysis.

HISTORY OF POLIO VACCINE

Two types of polio vaccine (OPV, oral polio vaccine, and IPV, inactivated polio vaccine) were created in the 1950s. Both were highly effective in preventing polio. Initially OPV was preferred because it helped to increase community immunity to polio.

However, about 1 out of 2.4 million doses of OPV distributed in the United States actually caused vaccine-associated paralytic polio (VAPP). In an effort to reduce this terrible side effect, a new polio vaccine schedule was recommended in 1997 (two doses of IPV followed by two doses of OPV). The new schedule decreased, but did not guarantee elimination, of vaccine-induced paralytic polio; so, effective in the year 2000, an all-IPV schedule was recommended, and OPV is no longer administered in the U.S. OPV continues to be used in countries where wild polio infections still occur.

TWO TYPES OF POLIO VACCINATION

• Polio Vaccine Inactivated (IPV)
• IPV in combination with DTaP (Diphtheria-Tetanus-acellular Pertussis) and hepatitis B vaccines

CURRENT SCENARIO

Normally, immunization is an integrated part of a broader package of mother and child health services. High infant immunization coverage through routine immunization delivers four doses of polio vaccine in the first year of life. However, immunization campaigns for polio carried out in a vertical approach using the health care system have been disruptive for the delivery of other basic services.

At a time when the world is approaching (we hope) the goal of eradication, polio campaigns have become so frequent that there is hardly any space left for basic routine health programs in the last endemic countries. In an environment of constrained resources, health workers are taken away from their routine daily activities—including immunization—to work on the campaigns.

A strong routine country immunization system is essential to achieve and sustain polio-free status. Three trends provide evidence for this:  1) In all three of the last remaining countries with endemic polio (Afghanistan, Pakistan and Nigeria), full, age-appropriate coverage of routine immunization services is low. 2) The last few years have seen outbreaks of polio in 12 countries that already had been declared polio-free, due to virus reintroduction from endemic countries. Those countries which had a strong routine immunization program with high coverage were able to quickly bring polio transmission under control. 3)  Most countries with high coverage of routine immunization never needed campaigns to eliminate polio from their territories.

The World Bank has been supporting polio eradication through targeted efforts in a number of countries including Nigeria, Pakistan and Afghanistan, as well as through broader health programs in countries like Yemen and India. The disease disproportionately affects poor regions and countries with limited fiscal space for disease control programs.  Investments in polio are demonstrably pro-poor, but eradication will benefit all future generations in all countries, rich and poor. There’s no question it would be a global public good.

The costs of stopping polio are substantial—more than should reasonably be borne alone by those countries where the epidemic persists. This requires a more holistic approach, ensuring that systems are in place that can ensure delivery of basic health services, including immunizations. Strengthening health systems and supporting routine immunization, the neglected pillar of GPEI, should both be a high priority.