1.45 million children's lives saved by HiB and pneumococcal vaccines since 2000

June 11, 2018, Johns Hopkins University Bloomberg School of Public Health
A black and white X-ray picture showing a triangular white area on the left side. A circle highlights the area. Credit: James Heilman, MD./Wikipedia

Childhood deaths from two leading bacterial causes of pneumonia and meningitis, pneumococcus and Hib, declined sharply during the period 2000 to 2015, especially as vaccines against these pathogens were introduced in high-burden countries, according to new estimates from a team led by scientists at Johns Hopkins Bloomberg School of Public Health.

The findings, published in The Lancet Global Health on June 11, highlight the success of the global fight against these illnesses, and also provide a clear picture of the remaining disease burden, now largely concentrated in South Asia and Africa.

"Further progress against these diseases will depend on efforts in a few large countries," says study lead author Brian Wahl, Ph.D., an assistant scientist at the International Vaccine Access Center in the Bloomberg School's Department of International Health. "These bacteria still cause far too many deaths."

Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae () are bacteria that can cause meningitis, pneumonia, sepsis and other serious complications, especially in children. They have been major causes of child mortality in developing countries. Estimates for the year 2000 showed about 2.1 million severe infections and 299,000 child deaths from Hib, and 6.6 million severe infections and 600,000 child deaths from pneumococcus—not including cases of opportunistic infection in children with HIV.

Conjugate vaccines against Hib have been used in the U.S., Europe and some other countries for almost three decades. They virtually eliminated Hib as a significant public health threat in areas of high and sustained coverage. However, children in several developing countries with high disease burdens have only started to receive Hib in the past decade. A vaccine against pneumococcus, known as the pneumococcal conjugate vaccine (PCV), began to be used in many low-income countries, where much of the disease burden is found, in 2009.

Wahl and colleagues developed updated estimates—on a country-by-country basis, for each year from 2000 to 2015—of the numbers of Hib and pneumococcal disease cases and deaths in children. They used country-specific figures of children who died of pneumonia and meningitis, along with field-based evidence on the fraction of those deaths caused by pneumococcus and Hib, and WHO/UNICEF estimates of vaccine coverage to estimate the burden of pneumococcal and Hib deaths and cases.

Their primary findings were that both Hib and pneumococcus caused far fewer cases of severe disease and in children ages one to 59 months in 2015 compared to 2000. For Hib in 2015, there were approximately 29,500 child deaths, and for pneumococcus an estimated 294,000 child deaths. These figures suggest declines of 90 percent and 51 percent, respectively, from the estimated deaths in the year 2000.

The researchers estimated that Hib and pneumococcal deaths among children with HIV/AIDS also declined sharply—75 percent—from about 95,000 in 2000 to about 23,000 in 2015.

The sharp declines in child mortality from Hib and pneumococcus were due not just to the introduction of vaccines but also to general factors that have reduced pneumonia and meningitis deaths from all causes, such as better hygiene and access to health care. "In 2015 compared to 2000 fewer children died from all causes, not just Hib and pneumococcus," Wahl notes.

However, there was evidence that vaccines were specifically responsible for a considerable reduction in mortality. "The estimated average annual decline in child deaths from pneumococcus jumped from 3 percent during 2000-2010 to 8 percent after 2010 when many high-burden countries began widespread immunizations with PCV," Wahl says.

The researchers estimated that during 2000-2015 PCV prevented a total of about 250,000 child deaths—mostly after 2010—while Hib vaccines prevented 1.2 million child deaths. These figures do not include the prevented cases of pneumococcal and Hib deaths among children who were HIV-infected.

The new estimates will guide ongoing efforts to reduce the burdens of Hib and pneumococcal diseases, which together still kill approximately 900 per day around the world. The estimates suggest, for example, that about half of the pneumococcal in 2015 occurred in just four countries: India, Nigeria, Democratic Republic of the Congo and Pakistan. "The pneumoccocal disease burden is now limited to a small number of countries that have not introduced the vaccine or have not yet fully scaled the vaccines," Wahl says.

The introduction of Hib vaccine and PCV into high-burden, low-income countries since 2009 has occurred with the support of Gavi, the Vaccine Alliance, a public-private partnership of countries, WHO, UNICEF and other partners.

Explore further: Pneumonia, diarrhea are top killers of kids: UNICEF

More information: "Burden of Streptococcus pneumoniae and Haemophilus influenzae type b disease in children in the era of conjugate vaccines: global, regional, and national estimates for 2000-15" The Lancet Global Health, 2018.

A commentary on the paper from the Respiratory Disease Branch Chief of the Centers for Disease Control and Prevention, Cynthia Whitney, MD, appears in the same issue.

Related Stories

Pneumonia, diarrhea are top killers of kids: UNICEF

June 8, 2012
Pneumonia and diarrhea are among the top causes of childhood deaths around the world, particularly among the poor, said a report out Friday by the UN Children's Fund.

Gaps in vaccine coverage highlighted with new report and online tool

May 24, 2016
As the 69th World Health Assembly discusses progress on the Global Vaccine Action Plan, a new data visualization platform—from the International Vaccine Access Center (IVAC) at the Johns Hopkins Bloomberg School of Public ...

Recommended for you

Study reveals new therapeutic target for slowing the spread of flu virus

June 22, 2018
Influenza A (flu A) hijacks host proteins for viral RNA splicing and blocking these interactions caused replication of the virus to slow, according to new research published in Nature Communications by Kristin W. Lynch, Ph.D., ...

First ancient syphilis genomes decoded

June 21, 2018
An international research team, including scientists from the Max Planck Institute for the Science of Human History, the University of Tübingen, the National School of Anthropology and History in Mexico City, and the University ...

Rhesus macaque model offers route to study Zika brain pathology

June 21, 2018
Rhesus macaque monkeys infected in utero with Zika virus develop similar brain pathology to human infants, according to a report by researchers at the California National Primate Research Center and School of Veterinary Medicine ...

California Aedes mosquitoes capable of spreading Zika

June 21, 2018
Over the last five years, Zika virus has emerged as a significant global human health threat following outbreaks in South and Central America. Now, researchers reporting in PLOS Neglected Tropical Diseases have shown that ...

Breakthrough treatment for crippling jaw disease created

June 20, 2018
A first-ever tissue implant to safely treat a common jaw defect, known as temporomandibular joint dysfunction, has been successfully tested by UCI-led researchers in a large animal model, according to new findings.

Cell-free DNA profiling informative way to monitor urinary tract infections

June 20, 2018
Using shotgun DNA sequencing, Cornell University researchers have demonstrated a new method for monitoring urinary tract infections (UTIs) that surpasses traditional methods in providing valuable information about the dynamics ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.