Pneumonia: a VaccinesWork guide
This week VaccinesWork is casting its spotlight on pneumonia, killer of more than 700,000 young kids each year. Stick with us to learn what vaccines can do, and are already doing, to make prevention a rule instead of a possibility.
- 11 November 2024
- 4 min read
- by Maya Prabhu , James Fulker
A pathogen – let’s say it’s Streptococcus pneumoniae, the most common bacterial culprit – enters through an airway. No big deal, this happens all the time.
But in this case, the immune system is immature (our imaginary patient is a toddler), and the defences of her upper respiratory system fail to spot and clear the threat.
Infection makes it down into the lungs, a part of the body far less accustomed to viral and bacterial invaders than the nose and throat. Here both the bacteria and the body’s response to them begin to do dangerous damage.
The immune fightback triggers inflammation. Air sacs in the lungs – on better days, the sites of the unimpeded exchange of oxygen and carbon dioxide – begin to fill with fluid: pus, essentially. The lungs stop working as they should.
The patient is coughing, bringing up foul-coloured mucus, but deep breaths are now out of reach, and she starts to take quick little staccato sips of air. Carbon dioxide is building up. Her breathing accelerates, but not enough oxygen is making it into the blood. Her nails and lips are turning blue.
Get her to a hospital in time, where doctors and nurses can supply extra oxygen and the antibiotics that can help her struggling body knock back the infection, and the pneumonia doesn’t have to turn deadly.
But each year, 740,000 children under the age of five do die of pneumonia, accounting for a staggering 14% of all deaths in that age group, and 22% of all deaths in children between one and five years of age.
Making robust medical care reliably available to children everywhere would change those figures drastically. And very often, a far simpler intervention can head off the threat of pneumonia before infection even takes hold.
Vaccines have already saved vast numbers of lives from pneumonia. Take the colossally impactful pneumococcal conjugate vaccine (PCV), which protects against Streptococcus pneumoniae.
Gavi helped get PCV to some 438 million children in 64 countries between 2009 and the end of 2023, which staved off an estimated 1.2 million deaths. And Gavi is continuing to broaden its reach: in 2024–2025, for instance, Chad, Somalia and South Sudan are introducing PCV into their routine immunisation systems for the first time with Gavi’s support, in a development that may mean as many as a million more children are protected, and 10,000 more deaths are averted.
PCV isn’t our only weapon in this fight, because pneumonia can be precipitated by a variety of pathogens. Hib vaccines – usually delivered as part of the basic five-in-one pentavalent or the six-in-one hexavalent jab – defend against a bacterium that caused 299,000 child deaths a year before Gavi was established.
Other vaccines stop viruses that open the door for bacterial pneumonias – measles, for instance, typically kills by knocking out the immune system and letting other pathogens take hold. Bacterial pneumonias are a common cause of measles-linked death, and measles vaccines are estimated to have prevented a staggering 57 million deaths, in aggregate, between 2000 and 2022.
Can you put a price on that? Well, yes, actually.
Let’s return to PCV as a case in point. Gavi pumped US$ 1.47 billion into its pneumococcal vaccine programme between 2021 and 2025 – an investment that saved not only lives, but also contributed to an estimated US$ 33.4 billion of savings in the cost of coping with illness between 2009 and 2023.
In the next five-year period, Gavi projects a spend of US$ 1 billion– complemented by increasingly stout investment from the countries Gavi supports – on its PCV programme. But that spend depends on the success of Gavi’s ongoing push to rase a total of US$ 9 billion to fund all of its programmes, across the entire vaccine portfolio, for the period through 2030. Read more about that here.
We leave you with a selection of our favourite pneumonia stories from the archive.
- The editors
Severe pneumonia in decline in Nigeria following pneumococcal vaccine roll-out
Since PCV joined the roster of routine jabs in Nigeria, researchers find a measurable reduction in the burden of pneumonia, while health workers on the frontlines say fewer mothers’ hearts are being broken.
Childhood pneumonia deaths “greatly reduced” in Kenya following PCV vaccination
Pneumonia is still the leading killer of young children world-wide, but Kenyan doctors and researchers say that rates of the lung infection have dipped substantially since pneumococcal conjugate vaccines were introduced in 2011.
Five charts on the growing pneumonia crisis
Pneumonia is the leading cause of death in kids under five years, and the COVID-19 pandemic is making the pneumonia crisis worse. To coincide with World Pneumonia Day, we look at how numbers have risen and how vaccines can make a difference.
How surveillance can detect shape-shifting bacteria to stop them evading vaccines
Pneumococcal conjugate vaccines have saved millions of lives, but some bacterial strains have evolved to evade them. Genetic sequencing could help vaccine-makers stay one step ahead of the pathogen.
Vaccine profiles: Pneumococcus
Pneumococcal vaccines have substantially reduced deaths from pneumonia and meningitis, but they don’t protect against all bacterial strains, and antibiotic resistance is a growing threat.
More from Maya Prabhu
