Pneumonia is an infection of the lungs — specifically the alveoli (air sacs) — causing them to fill with fluid or pus. It can be caused by bacteria (most commonly Streptococcus pneumoniae), viruses (influenza, RSV, SARS-CoV-2) or fungi. Bacterial pneumonia is typically more severe and requires antibiotic treatment. Symptoms include cough, fever, difficulty breathing, chest pain and fast breathing.

Why is pneumonia still the leading infectious killer of children?

Despite being preventable and treatable, pneumonia kills 740,000 children per year because of gaps in: vaccination (PCV and Hib coverage remains incomplete); nutrition (malnourished children have greatly increased susceptibility); oxygen availability (hypoxaemic pneumonia is fatal without supplemental oxygen, which is unavailable in many LMIC health facilities); antibiotic access (amoxicillin is cheap but supply chains are unreliable); and care-seeking (caregivers may not recognise warning signs or be able to reach health facilities).

How is pneumonia diagnosed?

In primary care settings in LMICs, WHO IMCI (Integrated Management of Childhood Illness) uses fast breathing (above age-specific respiratory rate thresholds) and chest indrawing as key diagnostic criteria — enabling diagnosis without X-ray or laboratory tests. In hospital settings, chest X-ray, pulse oximetry and sputum culture are standard. Rapid antigen tests for S. pneumoniae (urine antigen) and point-of-care PCR panels are increasingly used in high-income settings.

What vaccines prevent pneumonia?

The three most important vaccines for pneumonia prevention are: pneumococcal conjugate vaccine (PCV) — targets S. pneumoniae, the most common bacterial cause; Hib vaccine — prevents H. influenzae type b pneumonia and meningitis; and influenza vaccine — prevents influenza-associated pneumonia, particularly important in older adults and high-risk groups. RTS,S/R21 malaria vaccines also indirectly reduce pneumonia burden in malaria-endemic settings. Measles vaccination prevents measles-associated pneumonia, a leading child killer.

How is bacterial pneumonia treated?

Community-acquired bacterial pneumonia in children is treated with amoxicillin (oral) for non-severe cases or parenteral ampicillin for severe cases. In adults, the choice of antibiotic depends on severity, risk factors and local resistance patterns. Atypical pneumonia (Mycoplasma, Chlamydophila) requires a macrolide (azithromycin) or doxycycline. Vital supplementary treatment for severe pneumonia is oxygen therapy for hypoxaemia. Duration is typically 5-7 days; antibiotic stewardship is essential to avoid AMR.

What is the role of oxygen in pneumonia treatment?

Supplemental oxygen is a life-saving treatment for children and adults with hypoxaemic pneumonia — when blood oxygen saturation falls below 90%. It prevents organ damage and death from hypoxaemia. However, functional oxygen systems (cylinders, concentrators, delivery equipment, pulse oximetry) are absent or unreliable in an estimated 70% of health facilities in LMICs. The COVID-19 pandemic brought unprecedented attention to the oxygen access crisis; WHO and partners are now scaling up oxygen systems globally.

What is COVID-19 pneumonia?

SARS-CoV-2 causes a distinctive bilateral viral pneumonia (COVID-19 pneumonia) characterised by ground-glass opacities on CT scan, a tendency toward sudden deterioration 7-10 days after symptom onset, and cytokine storm-driven hyperinflammation. Unlike typical bacterial pneumonia, it responds to dexamethasone (corticosteroids) and anticoagulation but not to antibiotics. COVID-19 was the most common single cause of pneumonia-related deaths globally in 2020 and 2021.

How does malnutrition affect pneumonia risk?

Malnutrition — particularly severe acute malnutrition — dramatically increases a child's susceptibility to pneumonia and the risk of death if infected. Malnourished children have impaired immune function, impaired mucociliary clearance and structural lung underdevelopment. Zinc deficiency specifically impairs immune responses to respiratory pathogens. Ready-to-use therapeutic food (RUTF) that corrects severe acute malnutrition is therefore also an indirect pneumonia prevention intervention.

What is hospital-acquired pneumonia (HAP)?

Hospital-acquired pneumonia (HAP) develops 48+ hours after hospital admission. Ventilator-associated pneumonia (VAP) — occurring in mechanically ventilated patients — is the most serious form, with mortality rates of 20-50%. HAP is commonly caused by drug-resistant organisms (MRSA, Gram-negative bacteria), making it a key AMR concern. Prevention through ventilator care bundles, hand hygiene and antibiotic stewardship is a core patient safety priority.

The Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) — launched by WHO and UNICEF in 2013 — provides an integrated framework for addressing the two leading infectious killers of children simultaneously. The protect-prevent-treat framework addresses: breastfeeding and nutrition (protect); vaccination, hand hygiene, WASH, HIV prevention (prevent); and early recognition, appropriate antibiotics and oxygen (treat). Coverage of GAPPD interventions would prevent the vast majority of child pneumonia and diarrhoea deaths.

Which countries have the highest pneumonia burden?

The 15 countries with the highest burden account for approximately 76% of all child pneumonia deaths globally: Nigeria and the Democratic Republic of Congo together account for over one third. India, Pakistan, Ethiopia, Angola, Chad, Mali, Niger, Somalia, Tanzania, Mozambique, Guinea, Uganda and South Sudan are the other highest-burden countries. These are all fragile, conflict-affected or very poor settings with the weakest health systems — demonstrating that pneumonia burden is primarily driven by poverty and health system access, not biology.

How does GMJ News cover pneumonia?

GMJ News tracks WHO/UNICEF pneumonia burden data, PCV rollout progress through GAVI, oxygen access initiatives, AMR trends in pneumonia, and clinical trial results for new pneumonia treatments. Pneumonia in the South Caucasus context — including AMR resistance patterns and case management quality — is directly relevant to PHIG's accreditation and public health work and the Georgian Medical Journal.

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Pneumonia

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Pneumonia remains the single largest infectious cause of death in children worldwide, killing more young children than any other infectious disease — the vast majority in low- and middle-income countries, from causes that are preventable with vaccines (PCV, Hib, measles, pertussis) and treatable with low-cost antibiotics and oxygen (WHO). In adults, lower respiratory infections consistently rank among the top global causes of death, with pneumococcal disease, influenza, RSV and — increasingly — antimicrobial resistance shaping outcomes. GMJ News tracks the vaccine, oxygen-access and AMR dimensions of a disease that medicine knows how to beat but the world has not yet chosen to.

Primary sources: WHO fact sheet — Pneumonia in children · WHO health topic — Pneumonia

Key messages

Leading infectious killer of children

Pneumonia killed approximately 740,000 children under 5 in 2019 — 14% of all under-5 deaths. It remains the single leading infectious cause of child mortality worldwide despite effective vaccines and treatments.

Vaccines prevent it

The pneumococcal conjugate vaccine (PCV), Haemophilus influenzae type b (Hib) vaccine and influenza vaccine together prevent a large proportion of childhood pneumonia. PCV coverage has expanded dramatically since GAVI financing became available.

Antibiotics treat it

Bacterial pneumonia — the most lethal form — is highly treatable with antibiotics (amoxicillin, co-trimoxazole). The challenge is that pneumonia is often not diagnosed or treated in time, particularly in LMICs where access to care is limited.

AMR threat

Antimicrobial resistance is making pneumonia harder to treat. Drug-resistant Streptococcus pneumoniae, Klebsiella pneumoniae and Staphylococcus aureus are increasingly common causes of severe and treatment-resistant pneumonia.

Adults at risk too

Pneumonia is also a major killer in older adults — community-acquired pneumonia is a leading cause of adult hospitalisation globally. Pneumococcal and influenza vaccination of older adults substantially reduces community-acquired pneumonia.

GAPPD

The Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea (GAPPD) — the WHO/UNICEF integrated strategy — targets ending preventable pneumonia deaths in children under 5 through a protect-prevent-treat framework.

Key statistics

740K

child under-5 deaths/year (2019)

WHO/UNICEF

14%

of all under-5 deaths

UN IGME 2023

~2.5M

total pneumonia deaths/year all ages

GBD 2019

infectious killer of children globally

WHO

50%

reduction in child pneumonia deaths 2000-2019

UNICEF

76%

of pneumonia deaths in 15 highest-burden countries

WHO

Child deaths from pneumonia under age 5 globally (thousands) 2000-2019 — WHO/UNICEF

Source: WHO/UNICEF/UN IGME. Substantial decline from 1.7M (2000) to 740K (2019) driven by PCV rollout, nutrition and case management.

Glossary of key terms

Community-acquired pneumonia (CAP)
WHO/ATSPneumonia acquired outside of hospital settings — in contrast to hospital-acquired pneumonia (HAP). CAP is caused by Streptococcus pneumoniae most commonly, plus Mycoplasma pneumoniae, Haemophilus influenzae, and viruses including influenza and SARS-CoV-2.

Pneumococcal conjugate vaccine (PCV)
WHO/SAGEA vaccine protecting against Streptococcus pneumoniae — the most common bacterial cause of pneumonia and meningitis. PCV13 and PCV15/20 are the current formulations. WHO recommends PCV in all national immunisation programmes; GAVI financing has enabled rollout across LMICs.

Hypoxaemia
WHO/UNICEFLow blood oxygen saturation — present in severe pneumonia when gas exchange is impaired. Pulse oximetry detects hypoxaemia before it is clinically apparent. Supplemental oxygen is a life-saving treatment for children with hypoxaemic pneumonia — but oxygen availability is severely limited in many LMICs.

Fast breathing
WHO IMCIThe WHO Integrated Management of Childhood Illness (IMCI) uses fast breathing (respiratory rate above thresholds for age) as the primary diagnostic criterion for pneumonia diagnosis in primary care settings without X-ray access — enabling case identification by community health workers.

Hib vaccine
WHO/SAGEHaemophilus influenzae type b vaccine — prevents bacterial meningitis and pneumonia caused by Hib. Hib was the second most common bacterial pneumonia cause in children before universal vaccination. Global Hib vaccine coverage is now above 70%.

Aspiration pneumonia
WHOPneumonia caused by inhalation of oral secretions, food, liquid or vomit into the lower airways. Common in older adults with swallowing dysfunction (stroke, dementia, Parkinson's), intubated patients and people with impaired consciousness. The most common pneumonia type in nursing home residents.