Immunization

Immunization coverage

Fact sheet N°378       April 2013

Key facts

• Immunization prevents illness, disability and death from vaccine-preventable diseases including diphtheria, measles, pertussis, pneumonia, polio, rotavirus diarrhea, rubella and tetanus.
• Global vaccination coverage is holding steady.
• Immunization currently averts an estimated 2 to 3 million deaths every year.
• But an estimated 22 million infants worldwide are still missing out on basic vaccines.

Overview

Immunization averts an estimated 2 to 3 million deaths every year from diphtheria, tetanus, pertussis (whooping cough), and measles. Global vaccination coverage—the proportion of the world’s children who receive recommended vaccines—has remained steady for the past few years. For example, the percentage of infants fully vaccinated against diphtheria-tetanus-pertussis (DTP3) was 83% in 2011, 84% in 2010 and 83% in 2009.

During 2011, about 107 million infants worldwide got three doses of DTP3 vaccine, protecting them against infectious diseases that can cause serious illness and disability or be fatal. By 2011, 130 countries had reached at least 90% coverage of DTP3.

Current levels of access to recommended vaccines

Haemophilus influenza type b (Hib) causes meningitis and pneumonia. Hib vaccine was introduced in 177 countries by the end of 2011. Global coverage with three doses of Hib vaccine is estimated at 43%.

Hepatitis B is a viral infection that attacks the liver. Hepatitis B vaccine for infants had been introduced nationwide in 180 countries by the end of 2011. Global hepatitis B vaccine coverage is estimated at 75%.

Human papillomavirus — the most common viral infection of the reproductive tract — can cause cervical cancer, and other types of cancer and genital warts in both men and women. Human papillomavirus vaccine was introduced in 43 countries by the end of 2011.

Measles is a highly contagious disease caused by a virus, which usually results in a high fever and rash, and can lead to blindness, encephalitis or death. By the end of 2011, 84% of children had received one dose of measles vaccine by their second birthday, and 141 countries had included a second dose as part of routine immunization.

Meningitis A is an infection that can cause severe brain damage and is often deadly. By the end of 2012—two years after its introduction—the MenAfriVac vaccine, developed by WHO and PATH, was available in 10 of the 26 African countries affected by the disease.

Mumps is a highly contagious virus that causes painful swelling at the side of the face under the ears (the parotid glands), fever, headache and muscle aches. It can lead to viral meningitis. Mumps vaccine had been introduced nationwide in 120 countries by the end of 2011.

Pneumococcal diseases include pneumonia, meningitis and febrile bacteremia, as well as otitis media, sinusitis and bronchitis. Pneumococcal vaccine had been introduced in 72 countries by the end of 2011.

Polio is a highly infectious viral disease that can cause irreversible paralysis. In 2011, 84% of infants around the world received three doses of polio vaccine. Only three countries—Afghanistan, Nigeria and Pakistan—remain polio-endemic.

Rotaviruses are the most common cause of severe diarrhoeal disease in young children throughout the world. Rotavirus vaccine was introduced in 31 countries by the end of 2011.

Rubella is a viral disease which is usually mild in children, but infection during early pregnancy may cause fetal death or congenital rubella syndrome, which can lead to defects of the brain, heart, eyes and ears. Rubella vaccine was introduced nationwide in 130 countries by the end of 2011.

Tetanus is caused by a bacterium which grows in the absence of oxygen, e.g. in dirty wounds or in the umbilical cord if it is not kept clean. It produces a toxin which can cause serious complications or death. The vaccine to prevent maternal and neonatal tetanus had been introduced in over 100 countries by the end of 2011. Vaccination coverage with at least two doses was estimated at 70%, and an estimated 82% of newborns were protected through immunization. Maternal and neonatal tetanus persist as public health problems in 36 countries, mainly in Africa and Asia.

Yellow fever is an acute viral hemorrhagic disease transmitted by infected mosquitoes. As of 2011, yellow fever vaccine had been introduced in routine infant immunization programmers in 36 of the 48 countries and territories at risk for yellow fever in Africa and the Americas.

Key challenges

Despite improvements in global vaccine coverage during the past decade, there continue to be regional and local disparities resulting from:

• limited resources;
• competing health priorities;
• poor management of health systems; and
• inadequate monitoring and supervision.

In 2011, an estimated 22 million infants worldwide were not reached with routine immunization services. About half of them live in three countries: India, Indonesia and Nigeria.

Priority needs to be given to strengthening routine vaccination globally, especially in the countries that are home to the highest number of unvaccinated children. Particular efforts are needed to reach the underserved, especially those in remote areas, in deprived urban settings, in fragile states and strife-torn regions.

WHO response

WHO is working with countries and partners to improve global vaccination coverage, including through these initiatives adopted by the World Health Assembly in May 2012.

The Global Vaccine Action Plan

The Global Vaccine Action Plan (GVAP) is a roadmap to prevent millions of deaths through more equitable access to vaccines. Countries are aiming to achieve vaccination coverage of ≥90% nationally and ≥80% in every district by 2020. While the GVAP should accelerate control of all vaccine-preventable diseases, polio eradication is set as the first milestone. It also aims to spur research and development for the next generation of vaccines.

The plan was developed by multiple stakeholders—UN agencies, governments, global agencies, development partners, health professionals, academics, manufacturers and civil society. WHO is leading efforts to support regions and countries as they adapt the GVAP for implementation.

World Immunization Week

The last week of April each year is marked by WHO and partners as World Immunization Week. In 2013, more than 180 countries, territories and areas are expected to mark the week with activities including vaccination campaigns, training workshops, round-table discussions and public information campaigns. The theme of World Immunization Week is “Protect your world – get vaccinated”. It aims to raise public awareness of how immunization saves lives, encouraging people everywhere to vaccinate themselves and their children against deadly diseases.

Reference

http://www.who.int/mediacentre/factsheets/fs378/en/index.html