Q&A: Pharmacists Help Patients Navigate Pneumococcal Vaccine Options

The pneumococcal vaccine landscape has changed more in the past few years than it did in the previous decade. For pharmacists fielding patient questions about PCV15, PCV20, PCV21, and more, knowing not just which vaccine to recommend but why can help the most vulnerable populations stay protected against disease.

“If you’re going to try and explain the concept of serotype replacement, you could say something like, with the bacteria, there are more than 100 different types,” Paul Licciardi, PhD, group leader of vaccine immunology at the Murdoch Children’s Research Institute, told Drug Topics®. “Not all of them cause serious disease, but a fair majority do. As you introduce a vaccine, you’re going to get emergence of new types that we call replacement types.”

From the technical conversation around serotype replacement to the expanding pool of vaccine options, the pneumococcal vaccine landscape is one of the more unique areas of immunization and infectious disease. With pharmacists paramount in community vaccination efforts, their specific understanding of pneumococcal strains can benefit patients and their families across the country.

In part 2 of our conversation with Licciardi, he helps to better understand the pharmacist’s increasing role in keeping patients educated and updated in a rapidly evolving space.

READ MORE: Lowered Pneumococcal Vaccination Age Has Yet to Close Awareness Gap

Drug Topics: With PCV15, PCV20, and PCV21 all available, how should a pharmacist actually decide which one to reach for with a given patient?

Paul Licciardi: Yeah, it’s an interesting question. I think that is one of the key things in the pneumococcal field that’s rapidly evolved. At one point, it kind of felt like the vaccines we had, which were the 13-valent, the main vaccine for use in adults, were going to stay like that. But the bacteria have ways of evolving under vaccine pressure. You have these emergence of different types. That’s why we’ve seen the 15-valent, 20-valent, and now the 21-valent. I think it’s been licensed in the US for a little while. In Australia, it’s just literally become available last month.

I think in terms of recommendation, if you only had one of those vaccines available, you would vaccinate. They’re all very good vaccines; highly, highly effective. Of course, the increasing number of serotypes, going from 15 to 21, does add additional benefit. They’re all single-dose strategies, so you just need to give one vaccination. From that point of view, it’s important to consider that they’re all going to be highly effective. The only issue I would say is with the 15-valent because it does have slightly fewer serotypes. There is a general recommendation that if you have that dose, then you should follow that up with a vaccine of higher valency. That’s typically the polysaccharide vaccine, which is a 23-valent. But that’s a bit of a different story. I think the 23-valent has served its purpose. I think it’s becoming increasingly less used just because of the high-valency conjugate vaccines now.

Drug Topics: How crucial is the conversation of serotype replacement between pharmacists and their patients?

Paul Licciardi: Serotype replacement is quite a technical kind of concept. And so most patients probably will find that difficult to grasp. In its simplest term, it’s essentially what the name means. You have replacement of serotypes that used to be around with newer ones. If you’re going to try and explain that concept, you could say something like, with the bacteria, there are more than 100 different types. Not all of them cause serious disease, but a fair majority do. As you introduce a vaccine, you’re going to get emergence of new types that we call replacement types.

We can fall back on that current situation where we’ve got these newer valency vaccines. They’re really designed because of this issue. So, if it comes back to that question, ‘Okay, what about 20-valent versus 21 or 15? Why do we have all these different combinations?’ It’s really just due to the ongoing change in what’s circulating. Like with flu, you have different strains always every year. You’ve got to update the vaccines. It’s kind of a similar concept to that. It’s probably not necessary to get into the technicalities of serotype replacement. I think just as a broader concept is that’s really what’s driving these new vaccines. If there’s an updated vaccine available, and you had a choice, yes, you would go for the higher valency vaccine.

I think it’s good to be aware. I think as pharmacists, any health care providers, it’s important to be aware of these vaccines, because it’s not necessarily common knowledge. I think it’s something that they should be aware of. Why are we keeping change with the vaccinations? That’s something that everybody should be mindful of.

READ MORE: Pneumococcal Resource Center