The panelists discuss the evolution of the pneumococcal vaccine landscape.
Ryan Haumschild, PharmD, MS, MBA: When we hear about these vaccines, a lot of patients are like, “Wow, there’s so many. Why are there so many?” Ms Madison, it’s intentional that we have new vaccines being brought forward. They cover different serotypes, there’s different clinical information and impacts. Maybe you could answer this question: why was it necessary for the development of 2 new pneumococcal [conjugate] vaccines, PCV15 and PCV20?
Christina Madison, PharmD, FCCP, AAHIVP: The 2 vaccines are doing 2 different things. Historically we vaccinated the child vector burden, which helps with the infection in adults. We’re looking at the selection of noncovered serotypes in what we see, the infectious burden. When we look at the disease burden, 50% of all pneumococcal meningitis cases are from invasive pneumococcal types. The ones that are part of the serotypes are included in the vaccines. That accounts for 2000 cases per year and almost 150,000 hospitalizations associated with pneumococcal pneumonia. That’s why we still have such a significant disease burden that we need to impact, and that’s why we needed both vaccinations. One is targeting that reservoir disease burden in our pediatric population as well as accounting for serotypes that aren’t already part of the PPSV23 [pneumococcal polysaccharide vaccine 23]. So there are unique serotypes in both of those conjugate vaccines.
The conjugation process is different. When you think about a side chain, the immunosenescence that occurs as we age is why the PPSV23 is so good at what it does. It’s a giant side chain. It’s wiggling, “Look at me.” That’s what our immune system needs because, unfortunately, the conjugate itself doesn’t have that giant side chain, so it’s not as recognizable. We need a couple of more bites at the apple, a few more exposures to get the most amount of immune response from our patients. You’re getting 2 different aspects with both vaccines, and they’re definitely both needed within the market.
Ryan Haumschild, PharmD, MS, MBA: That was a great descriptor. I appreciate “bites at the apple,” which is very true. That’s what we need to fight this infectious disease. When we think about these different vaccines, something that comes to mind is, what are some of the safety and immunogenicity data? Ms Bridgeman, can you touch on the key safety and immunogenicity data that led to the FDA approvals of PCV15 and PCV20?
Mary Bridgeman, PharmD, BCPS, BCGP, FASCP: The PCV15 and the PCV20 vaccines were licensed by the Food and Drug Administration in 2021 for youth and adults based on studies comparing the serological response of adults who received either vaccine preparation to those who had received PCV13. Studies showed that PCV15 and PCV20 induced antibody levels that were comparable with those associated with the PCV13 vaccine preparation, and that the PCV15 and PCV20 were also safe when compared with the PCV13 product. PCV15 was licensed in 2022 for children 6 weeks through 17 years of age, based on the clinical trial data that demonstrated that PCV15-induced antibody levels that were comparable with levels of PCV13 and also that PCV15 was safe in this particular population. We were talking about immunizing children as a mechanism of population health. That’s critical information to include in this discussion as well.
Ryan Haumschild, PharmD, MS, MBA: I want to ask a question focusing on the clinical practice and the discretionary use of these vaccinations and the different available approaches. Let’s start with Mr Schaffner. In your clinical practice, when would you use the newer pneumococcal vaccinations like PCV15 or PCV20 instead of the ones we consider more traditional, such as PCV13 and PPSV23?
William Schaffner, MD: First, PCV13 is on the way out. It’s being replaced by the manufacturer with PCV20. In the adult environment, we’ll have PCV15, PCV20, and polysaccharide vaccine 23. We’ll be dealing with 3 vaccines. The CDC [Centers for Disease Control and Prevention] and the Advisory Committee on Immunization Practices [ACIP] provide us with 2 options. They have not expressed a preference. You can use dominantly the PCV20 or the PCV15 followed by the polysaccharide vaccine. The ACIP considers them comparable. There are going to be a myriad of practice circumstances, from large medical centers to solo practitioners, group practices, and all kinds of settings with previous purchasing arrangements and discussions within each group deciding which vaccine to use. This will continue to vary across the country. I’ll emphasize that the CDC hasn’t expressed a preference.
You asked about my own circumstance. I live and work in a medical center where our vaccine committee followed what our doctors have started to do. They’ve moved largely to using PCV20. That was their choice, and that’s what our vaccine committee decided to do. We’re there, but that’s just 1 medical center. There are all kinds of options, and I look forward to Ms Madison’s comments.
Christina Madison, PharmD, FCCP, AAHIVP: Thank you for that lovely intro. I’ll definitely echo the sentiments that we’re seeing this transition away from PCV13 to PCV15 as we move away from that indication in our pediatric patient population to assist with that reservoir for possible infectious risk for our higher-risk adult population. Why would we use 1 over the other, and what are the benefits? There are a couple of reasons. No. 1, are we looking at a population for whom it might also be beneficial to give them the PPSV23? The order should be the PCV15 first and the PPSV23 second. If they’re immunosuppressed and very high risk, then that would be 8 weeks apart. But for most individuals, 1 year or more is fine.
For the PCV20, the CDC hasn’t specified 1 over the other, and most of my expertise is in public health…. When you look at the allocation, especially the Vaccines for Children and Section 317 programs—the adult equivalent for those who are uninsured or underinsured and can’t afford their vaccinations—having both products available is appropriate. It’s what works in that FQHC [Federally Qualified Health Center] space and for patients who are historically marginalized or have limited access to vaccine resources. Having both products is going to be appropriate because they may have another indication to receive the PPSV23. However, let’s say they are otherwise healthy and have already had a version of pneumococcal vaccination prior to being 65 years old, but for whatever reason, they no longer have that risk for invasive pneumococcal disease, and we’re looking to seal the deal. Then the use of PCV20 is completely appropriate, especially because it’s 1 and done.
Transcript edited for clarity.