Pneumonie : un guide VaccinesWork

A pathogen – take for example Streptococcus pneumoniaethe bacteria most often involved – enters through the respiratory tract. Nothing unusual, it happens frequently.

But here, the immune system is still immature (our imaginary patient is a little girl), and her respiratory defenses do not identify the threat in time.

The infection spreads to the lungs, an area much less accustomed to viral and bacterial invaders than the nose and throat. There, bacteria and the body’s immune response begin to take their toll.

The immune response triggers inflammation. The lung alveoli – which normally allow the exchange of oxygen and carbon dioxide – fill with fluid, actually pus. The lungs no longer work properly.

The patient coughs, coughing up thick, colored mucus. She can no longer breathe deeply and begins taking small gulps of air. Carbon dioxide builds up. Her breathing speeds up, but she doesn’t get enough oxygen. Her nails and lips turn blue.

If he is taken to the hospital quickly, doctors can give him oxygen and antibiotics to help fight the infection. Pneumonia may then not become fatal.

Yet every year, 740,000 children under the age of five die from pneumonia, accounting for a frightening 14% of all deaths in this age group and 22% of deaths among children aged one to five.

Making quality medical care accessible to all children would dramatically change these numbers. And often, a much simpler intervention can stave off the threat of pneumonia before it even sets in.

Vaccines have already saved an immense number of lives. Let’s take the pneumococcal conjugate vaccine (PCV), the impact of which is colossal, because it protects against Streptococcus pneumoniae.

Thanks to Gavi, 438 million children in 64 countries received PCV between 2009 and the end of 2023, preventing around 1.2 million deaths. And Gavi continues to expand its work: in 2024-2025, Chad, Somalia and South Sudan will introduce PCV into their routine immunization programs with help from Gavi, which is expected to protect one million children additional and prevent 10,000 deaths.

PCV is not our only weapon in this fight, as various infections can trigger pneumonia. Vaccines against Haemophilus influenzae type b (Hib) vaccines – often given as part of the pentavalent (five-in-one) or hexavalent (six-in-one) vaccine – protect against a bacteria that once caused 299,000 child deaths each year before Gavi was created.

Other vaccines work against viruses that open the door to bacterial pneumonia – measles, for example, often kills by weakening the immune system and allowing other pathogens to take hold. Bacterial pneumonia is a common cause of measles-related deaths, and measles vaccines are estimated to have prevented 57 million deaths between 2000 and 2022.

Can we put a price on that? Yes, actually.

Let’s take PCV again as an example. Gavi invested $1.47 billion in its pneumococcal vaccination program between 2021 and 2025 – an investment that not only saved lives, but also approximately $33.4 billion in avoided medical costs.

Over the next five years, Gavi plans to spend $1 billion – with increasing investment from Gavi-supported countries – on its PCV program. But this funding depends on the success of Gavi’s current resource mobilization campaign, which targets $9 billion to fund all of its vaccination programs through 2030. Learn more here.

We leave you with a selection of our best articles on pneumonia from our archives.