Featured Issue: Pneumonia and vaccines

Boy with Pneumonia

Pneumonia vaccines - Secret weapons in the war on poverty

Childhood pneumonia is arguably the most unfair affliction in the world. Not only is pneumonia the leading infectious cause of death in children less than 5 years of age – taking the lives of more than 100 children each hour, nearly a million per year – but it disproportionately affects those living in the poorest households and in the poorest countries around the world. Hib, pneumococcal, measles and pertussis vaccines are turning the tide in the battle against childhood pneumonia, and are helping to erase the complex inequity into which children living in poverty are born. Read on to find out why and what role vaccines are playing in the war on poverty.

Poverty and pneumonia are closely linked

A description of the hardships associated with everyday life for children in poor households reads like a top ten list of risk factors for childhood pneumonia and pneumonia mortality. Common issues such as malnutrition, poor access to care, overcrowding, immune-compromising infections, low levels of parental education and more all contribute to the stark fact that a child born in the poorest fraction of society has many times the risk of pneumonia and death compared to a child born in the wealthiest fraction. Here we provide some of the most important ways in which poverty-associated factors impact a child’s risk of pneumonia:

 

The vicious cycle of poverty-associated risks

Sick kids get sick more often, negatively impacting growth and development

Children whose immune systems are weakened by factors more common among the poor – such as diarrhea, measles or malnutrition – are at significantly increased risk of pneumonia, which in turn increases the risk of subsequent infections and inhibits healthy physical growth and development.

  • recent review of data from developing countries found a negative feedback loop between pneumonia, diarrhea and malnutrition whereby suffering from of any one the three conditions increased a child’s risk for the other two.
  • Studies from Kenya to the Philippines to India have demonstrated how infections like pneumonia and diarrhea are linked to poor growth in childhood and can further impact an already weakened immune system
  • According to UNICEF, more than half of the children who die of pneumonia before their fifth birthday also suffer from undernutrition.
  • Among others, a study from the UK, Denmark and the US found that measles infection increased a child’s risk of other infections – such as pneumonia or diarrhea – for up to 3 years after recovering from measles.

 

Weakened immune systems mean greater risk of pneumonia

Rates of HIV infection in children are highest in some of the world’s poorest countries, especially in Africa. HIV and other conditions, such as sickle cell disease, compromise a child’s ability to fight off infections and increase the risk of pneumonia and death.

  • HIV exponentially increases the risk of pneumonia and pneumococcal infections among both children and adults. Data from South Africa found that HIV-positive people had more than 40 times the risk of invasive pneumococcal disease borne by HIV-negative
  • Sickle cell disease, which affects nearly a quarter of a million African children born each year, increases the risk of Hib disease by more than 12-fold and the risk of pneumococcal disease by more than 35 fold, according to a 2010 review of bacterial infections in African children.

 

Breathing polluted air = more pneumonia

Kids regularly exposed to indoor and outdoor air pollution are at greater risk of developing pneumonia. Indoor pollution is common among poor households whose meals are prepared over solid fuel fires in the home or who use these fuels for heating.

  • 2016 UNICEF Report noted that indoor air pollution contributed to more than 50% of pneumonias

 

Poor kids, and those with less educated parents, are less likely to be immunized

The relationship between poverty and education is well-documented and both factors have a significant and negative impact on the likelihood of vaccination among young children.

  • study from Uganda found that the children of mothers whose education continued past primary school were 50% more likely to have received scheduled vaccines than children of mothers with less education.
  • Data from WHO member states was analyzed by researchers who found that children born to mothers with some secondary education were over 25% more likely to have received the third dose of DTP than mothers with no education. (Note: Coverage with the third dose of DTP3 is the most commonly used indicator of routine immunization coverage and program strength.)
  • review of immunization coverage in India found that household wealth was directly correlated with the likelihood of immunization. Greater parental education also increased the likelihood of immunization.
  • Children living in slums have significantly lower vaccination rates than other children. A review of the health of kids in slums noted that vaccination rates among kids in slums in Niger were less than half that of other children.

 

The world’s poor will reap the most benefits from pneumonia vaccines

Given the significantly increased risk of pneumonia – and recurrent infections – borne by children in poverty, it stands to reason that these children will benefit the most from the protective boost afforded through vaccines such as Hib, pneumococcal and measles vaccines. By directly preventing infection with these common causes of severe pneumonia, vaccination against these diseases protects a child’s underlying health status – which in turn protects against other illnesses such as diarrhea – and facilitates healthy growth and development overall. The economic benefits of these vaccines for poor families and low-income nations are significant and will play a key role in meeting the Sustainable Development Goals.

 

Pneumonia vaccines help interrupt the vicious cycle of childhood infections and improve growth

  • A review of malnutrition and childhood infections in developing countries concluded not only that pneumococcal vaccine helps protect a child against subsequent illnesses like diarrhea but also measurably improves a child’s growth (height and weight).

 

Vaccines protect the most vulnerable and the unvaccinated

 

Vaccines against pneumonia increase health AND wealth equity

  • Between 2016 and 2030, researchers estimate that the use of pneumococcal and Hib vaccines in 41 low- and middle-income countries between will avert more than 1.25 million cases of medical impoverishment, a phenomenon where families are pushed below the poverty line due to the costs associated with medical treatment for childhood infections. More than half of the two million deaths averted through the use of these vaccines would occur among the poorest 40% of the population of these 41 countries. (Stay tuned to the VoICE eBulletin in April for an in-depth feature on this new study!)
  • -A study in Ethiopia found that 30-40% of all deaths averted by introducing PCV would occur in children in the lowest wealth quintile, while also protecting the poorest families from exposure to financial hardship
  • The costs of treating illness can be significant for families with little or no savings. Families in Bangladesh are heavily borrowing money or selling whatever assets they may have to afford treatment for their children
  • Similarly, in the Gambia, families are paying up to 10 times their daily household budget to cover the direct and indirect costs of treating pneumonia

 

Hib and Pneumococcal vaccines unlock a host of additional benefits

The Hib and pneumococcal bacteria are also important causes of meningitis, sepsis, ear infections and more. Protecting children from Hib and pneumococcal pneumonia thus carries the added benefits of protecting against these additional infections which themselves carry significant economic, health and cognitive costs. Stay tuned to future editions of the VoICE eBulletin to find out more about the benefits of Hib and pneumococcal vaccines, including:

  • Protection against life-threatening meningitis and sepsis
  • Tempering the threat of antibiotic resistance and overuse
  • Preventing long-term disabilities

A selection of VoICE evidence in this issue

Schlaudecker, E.P., Steinhoff, M.C. and Moore, S.R. 2011. Interactions of diarrhea, pneumonia, and malnutrition in childhood: recent evidence from developing countries. Current Opinion in Infectious Diseases. 24:496-502. Gewa, C.A. and Yandell, N. 2011. Undernutrition among Kenyan children: contribution of child, maternal and household factors. Public Health Nutrition. 15(6):1029-38. Adair, L.S. and Guilkey, D.K. 1997. Age-specific determinants of stunting in Filipino children. The Journal of Nutrition. 127:314-20. Coles, C.L., Rahmathullah, L., Kanungo, R., et al 2012. Pneumococcal carriage at age 2 months is associated with growth deficits at age 6 months among infants in South India. Journal of Nutrition. 142(6):1088-94. Mina, M.J., Metcalf, C.J. de Swart, R.L., et al 2015. Long-term measles-induced immunomodulation increases overall childhood infectious disease mortality. Science. 348(6235):694-9. Meiring, S., Cohen, C., Quan, V., et al 2016. HIV infection and the epidemiology of invasive pneumococcal disease (IPD) in South African adults and older children prior to the introduction of pneumococcal conjugate vaccine (PCV). PLOS ONE. 11(2). Ramakrishnan, M., Moisi, J.C., Klugman, K., et al 2010. Increased risk of invasive bacterial infections in African people with sickle-cell disease: a systematic review and meta-analysis. The Lancet Infectious Diseases. 10(5)329-37. Nankabirwa, V, Tylleskar, T., Tumwine, J., et al 2010. Maternal education is associated with vaccination status of infants less than 6 months in Eastern Uganda: a cohort study. BMC Pediatrics. 10:92. Hinman, A.R., and McKinlay, M.A. 2015. Immunization equity. Vaccine. 33(2015):D72-D77. Mathew, J.L. 2012. Inequity in childhood immunization in India: a systematic review. Indian Pediatrics. 49:203-23. Unger, A. 2013. Children’s health in slum settings. Archives of Disease in Childhood. 98(10):799-805. Madhi, S.A., Kuwanda, L., Cutland, C., et al 2005. The impact of a 9-valent pneumococcal conjugate vaccine on the public health burden of pneumonia in HIV-infected and -uninfected children. Clinical Infectious Disease. 40:1511-8. Ray, G.T., Whitney, C., Fireman, B., et al 2006. Cost-effectiveness of pneumococcal conjugate vaccine: evidence from the first 5 years of use in the United States incorporating herd effects. Pediatric Infectious Disease Journal. 25:494-501. Chang, A. Y., Riumallo-Herl, C., Perales, N. A., et al. 2018. The equity impact vaccines may have on averting deaths and medical impoverishment in developing countries. Health Affairs. 37(2), 316-324. Johannsen, K.A, Memirie, S.T., Pecenka, C. et al 2015. Health gains and financial protection from pneumococcal vaccination and pneumonia treatment in Ethiopia: Results from an extended cost-effectiveness analysis. PLOS ONE. 10(12). Alamgir, N.I., Naheed, A., and Luby, S.P 2010. Coping strategies for financial burdens in families with childhood pneumonia in Bangladesh. BMC Public Health. 10(622):1-7. Usuf, E., Mackenzie, G., Sambou, S., et al 2016. The economic burden of childhood pneumococcal diseases in The Gambia. Effectiveness and Resource Allocation. 14:4.