New vaccine may be the best option yet in preventing pneumococcal pneumonia

“Captain of the Men of Death” is the phrase Sir William Osler used in 1918 to describe pneumococcal pneumonia, the most widespread and fatal of all acute infectious diseases. While Streptococcus pneumoniae, or pneumococcus, remains the most commonly identified cause of community-acquired pneumonia, a new vaccine is available to prevent this infection. Streptococcus pneumoniae can cause many infections, including meningitis (infection of the membranes surrounding the brain and spinal cord) and sepsis (a severe bloodstream infection), but pneumonia remains the most common.

The pneumococcal vaccine is recommended for certain groups of people at high risk of contracting these infections, including adults 65+ years, and younger adults with compromised immune systems or those living with factors placing them at higher risk of pneumococcal disease. The vaccine tricks the immune system into thinking a natural infection occurred but does not reveal significant symptoms. The vaccine introduces a small piece of bacterial protein, conjugated to pneumococcal polysaccharides (sugar), a more potent stimulus to the immune system than polysaccharides alone. This response prepares the body to recognize and quickly fight the bacteria if it is encountered in the future.

We spoke with Dr. Chris Mody, MD, from the University of Calgary about this and other vaccines and their contribution to advances in health care. Dr. Mody is a clinician-scientist, professor, and member of the Snyder Institute for Chronic Diseases at UCalgary. After many years of study and a keen interest in pneumococcal vaccines, Dr. Mody shares his insights about the immense potential of another type of vaccine – the protein conjugate vaccine – and weighs its benefits against older pneumococcal vaccines.

“As a trainee in respiratory medicine, I became interested in pneumococcal vaccines. My extensive review of the literature on early polysaccharide-based vaccines helped me understand that they had minimal impact on preventing pneumonia, no matter how many repeated boosters are given to the patient. On the contrary, protein conjugate vaccines – specifically PCV13 (protein conjugate vaccine (PVV) that covers 13 different types of pneumococci) and now, the new PCV20 (covers 20 different types of pneumococci)– are much better and protect from pneumonia.”

Protein conjugate vaccines use a small piece of protein that is conjugated, or linked, to another molecule, such as a carbohydrate, to make it more easily recognized by the immune system.

PCV20 has been approved for use in Canada, and Dr. Mody said he was delighted when his family doctor recently asked if he had received PCV20. Unfortunately, PCV20 is not yet covered by Alberta Health, and patients may have to pay out of pocket to receive the vaccine. Dr. Mody and his colleagues have been actively researching vaccine efficacy and advocating for PCV20 to be approved and funded for patients with different types of underlying lung disease that puts them at risk of contracting pneumococcal pneumonia – considered the most widespread and fatal of all acute infectious diseases.

Protein conjugate vaccines are already being widely used in the European Union nations and the United States, particularly for protecting against infections caused by bacteria. The protein conjugate vaccines can trigger a more robust and targeted immune response than traditional vaccines.

“PCV20 is a potentially exciting healthcare advance,” concludes Dr. Mody. “With this vaccine, we can improve care for the health of patients at risk of contracting pneumococcal pneumonia.”

The Snyder Institute for Chronic Diseases is a research facility at the University of Calgary’s Cumming School of Medicine focused on advancing modern medicine’s capacity to ease the burden of chronic and infectious disease. Our 480 highly qualified researchers, clinicians and trainees use our world-class research facilities and technologies to make ground-breaking discoveries leading to disease prevention, tailored medical applications and ultimately cures for these conditions. Visit snyder.ucalgary.ca and follow @SnyderInstitute to learn more.