immunization chart

All about Immunization

Immunization Key facts

  • Immunization prevents illness, disability and death from vaccine-preventable diseases including cervical cancer, diphtheria, hepatitis B, measles, mumps, pertussis (whooping cough), pneumonia, polio, rotavirus diarrhoea, rubella and tetanus.
  • Global vaccination coverage has stalled at 86%, with no significant changes during the past year.
  • Uptake of new and underused vaccines is increasing.
  • Immunization currently averts an estimated 2 to 3 million deaths every year. An additional 1.5 million deaths could be avoided, however, if global vaccination coverage improves.
  • An estimated 19.5 million infants worldwide are still missing out on basic vaccines.


Immunization averts an estimated 2 to 3 million deaths every year from diphtheria, tetanus, pertussis (whooping cough), and measles; however, an additional 1.5 million deaths could be avoided if global vaccination coverage improves. Global vaccination coverage – the proportion of the world’s children who receive recommended vaccines – has stalled over the past few years.

During 2016, about 86% of infants worldwide (116.5 million infants) received 3 doses of diphtheria-tetanus-pertussis (DTP3) vaccine, protecting them against infectious diseases that can cause serious illness and disability or be fatal. By 2016, 130 countries had reached at least 90% coverage of DTP3 vaccine.

Global immunization coverage 2016

A summary of global vaccination coverage in 2016 follows.

Haemophilus influenzae type b (Hib) causes meningitis and pneumonia. Hib vaccine had been introduced in 191 countries by the end of 2016. Global coverage with 3 doses of Hib vaccine is estimated at 70%. There is great variation between regions. In the WHO Region of the Americas, coverage is estimated at 90%, while it is only 28% in the WHO Western Pacific Region. The WHO South-East Asia Region raised coverage from 56% in 2015 to 80% in 2016.

Hepatitis B is a viral infection that attacks the liver. Hepatitis B vaccine for infants had been introduced nationwide in 186 countries by the end of 2016. Global coverage with 3 doses of hepatitis B vaccine is estimated at 84% and is as high as 92% in the Western Pacific. In addition, 101 countries introduced one dose of hepatitis B vaccine to newborns within the first 24 hours of life, and the global coverage is 39%.

Human papillomavirus is the most common viral infection of the reproductive tract, and can cause cervical cancer, other types of cancer, and genital warts in both men and women. Human papillomavirus vaccine was introduced in 74 countries by the end of 2016, including four countries with introduction in some parts of the country.

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 2016, 85% of children had received one dose of measles vaccine by their second birthday, and 164 countries had included a second dose as part of routine immunization and 64% of children received two doses of measles vaccine according to national immunization schedules.

Meningitis A is an infection that can cause severe brain damage and is often deadly. By the end of 2016 – 6 years after its introduction – more than 260 million people in African countries affected by the disease had been vaccinated with MenAfriVac, a vaccine developed by WHO and PATH. Ghana and Sudan were the first two countries to include the MenAfriVac in their routine immunization schedule in 2016.

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 121 countries by the end of 2016.

Pneumococcal diseases include pneumonia, meningitis and febrile bacteraemia, as well as otitis media, sinusitis and bronchitis. Pneumococcal vaccine had been introduced in 134 countries by the end of 2016, including three in some parts of the country, and global coverage was estimated at 42%.

Polio is a highly infectious viral disease that can cause irreversible paralysis. In 2016, 85% of infants around the world received three doses of polio vaccine. Targeted for global eradication, polio has been stopped in all countries except for Afghanistan, Pakistan and Nigeria. Polio-free countries have been infected by imported virus, and all countries – especially those experiencing conflict and instability – remain at risk until polio is fully eradicated.

Rotaviruses are the most common cause of severe diarrhoeal disease in young children throughout the world. Rotavirus vaccine was introduced in 90 countries by the end of 2016, including six in some parts of the country, and global coverage was estimated at 25%.

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 152 countries by the end of 2016, and global coverage was estimated at 47%.

Tetanus is caused by a bacterium which grows in the absence of oxygen, for example in dirty wounds or in the umbilical cord if it is not kept clean. The spores of C. tetani are present in the environment irrespective of geographical location. It produces a toxin which can cause serious complications or death. The vaccine to prevent maternal and neonatal tetanus had been introduced in 106 countries by the end of 2016. An estimated 84% of newborns were protected through immunization. Maternal and neonatal tetanus persist as public health problems in 18 countries, mainly in Africa and Asia.

Yellow fever is an acute viral haemorrhagic disease transmitted by infected mosquitoes. As of 2016, yellow fever vaccine had been introduced in routine infant immunization programmes in 35 of the 42 countries and territories at risk for yellow fever in Africa and the Americas. In these 42 countries and territories, coverage is estimated at 45%.

Immunization exercise
Immunization Exercise in Nigeria

Key challenges

In 2016, an estimated 19.5 million infants worldwide were not reached with routine immunization services such as DTP3 vaccine. Around 60% of these children live in 10 countries: Angola, Brazil, the Democratic Republic of the Congo, Ethiopia, India, Indonesia, Iraq, Nigeria, Pakistan and South Africa.

Monitoring data at subnational levels is critical to helping countries prioritize and tailor vaccination strategies and operational plans to address immunization gaps and reach every person with lifesaving vaccines.

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 by 2020. To date, progress towards the GVAP targets is off track.

In May 2017, Ministers of Health from 194 countries endorsed a new resolution on strengthening immunization to achieve the goals of the GVAP. The resolution urges countries to strengthen the governance and leadership of national immunization programmes, and improve monitoring and surveillance systems to ensure up-to-date data guides policy and programmatic decisions to optimize performance and impact. It also calls on countries to expand immunization services beyond infancy, mobilize domestic financing, and strengthen international cooperation to achieve GVAP goals.

It requests the WHO Secretariat to continue supporting countries to achieve regional and global vaccination goals. It recommends scaling up advocacy efforts to improve understanding of the value of vaccines and urgency of meeting the GVAP goals. The Secretariat will report back to the Health Assembly in 2018, 2020 and 2022 on the achievements against the GVAP goals and targets.

World Immunization Week

The last week of April each year is marked by WHO and partners as World Immunization Week. It aims to promote the use of vaccines to protect people of all ages against disease. Immunization saves millions of lives and is widely recognized as one of the world’s most successful and cost-effective health interventions.

The main goal of the 2017 campaign with the theme #VaccinesWork is to raise awareness about the critical importance of full immunization throughout life, and its role in achieving the Sustainable Development Goals.

As part of the campaign, WHO and partners aim to:

  • Highlight the importance of immunization as a top global health investment priority.
  • Promote understanding of the action steps required to achieve the GVAP.
  • Showcase immunization’s role in sustainable development and global health security.

Culled from WHO website: Immunization Coverage Fact Sheet

Also read “Immunization for Children: What you need to know