Different Types and Formulations of Flu Vaccines

Troy Trygstad, PharmD, MBA, PhD; Brian Hille, BSPharm, RPh; and John Beckner, BSPharm, RPh, identify the types and formulations of influenza vaccines available.

Troy Trygstad, PharmD, MBA, PhD: Let’s get into the different types of flu vaccinations. So, there is some nuance there that we want to be able to update pharmacists with. And Brian, there’s monovalent, trivalent, quadrivalent; hopefully, we get north of 4. But let’s just start with, what do we mean by valent? And then fast-forward us to where are we at in the product array in 2018.

Brian Hille, BSPharm, RPh: Yes, so, simply, it’s the strains that happen to be inside of that vaccine. So, when you start talking about trivalent, it has 3 different strains of flu vaccine that are actually contained within the vaccine. Quadrivalent obviously has 4. What they did was, they added 1 more B strain to that vaccine, which gave it a total of 4. So, with the trivalent, you’ve got 3 different strains, and with the quadrivalent, you add 1 more B strain so you get 4 strains.

Troy Trygstad, PharmD, MBA, PhD: And every year, a group of really smart people get together early in the season and try to figure it out. I’m imagining this roulette board with some 50 numbers on it with 50 different strains. And if they say, “If we’ve got trivalent, we’ve got 3 chips that we can put on 3 different spaces, and if we got quadrivalent, we’ve got 4 chips on 4 different spaces,” then what’s your take right now on coverage over the past couple of years of experience and the importance of guessing correctly on which strains are going to emerge over the course of the flu season?

Brian Hille, BSPharm, RPh: Well, I would love to say it’s a perfect science, and there’s obviously people who spend their entire careers looking at this and, obviously, evaluating what’s happening in the southern hemisphere to determine what we do in the northern hemisphere. There is an entire protocol that goes behind this in a huge decision-making process. Like I say, everyone’s best intention is to nail it on the head. It’s still nature, and it evolves over time, and so hitting it on the head is a little more difficult some years than others. So, there’s always a little bit more comfort level for me when I know I’ve got 4 different strains inside the vaccine rather than 3, a little bit better chance of having a match.

Troy Trygstad, PharmD, MBA, PhD: Probably a little bit better chance. So, hopefully, we’ll see some products emerge in the future that have the ability to cover more of those spaces on the board.

John Beckner, BSPharm, RPh: And Troy, just to interject, I think the CDC has actually recommended a reduction in the production of a trivalent vaccine with the move toward quadrivalent.

Troy Trygstad, PharmD, MBA, PhD: So, that’s important.

John Beckner, BSPharm, RPh: Yes.

Troy Trygstad, PharmD, MBA, PhD: So, it’s scientific and policy validation that we want as many valents in there as possible. Let’s talk about regional variation. Where this comes to mind most is with viruses, obviously Zika, right? And so, if we think about that, it’s a concept of hot spots that are more at risk—yellow fever, other types of endemics, pandemics, and pathogens. When it comes to influenza, do we have regional variation, regional risk, places in the country it hits sooner rather than later? Timing can matter. If it hits in Iowa first, then the Iowa folks mobilize more quickly than those in Georgia. You’ve got 1700 stores, Brian. How do you handle it? You’ve got 1 store in an area where there’s an outbreak going on and a store not in the area—what does that dynamic look like?

Brian Hille, BSPharm, RPh: It’s actually pretty interesting every year, so we watch it very, very closely. CDC does a very nice job of mapping how the virus is moving through the United States, and so you can pull up a map and take a look at it. There are other resources through Google that kind of project where the flu is hitting. But we watch it very, very closely, because it gives us a very good indication of where we need to get extra vaccines, where we need to put people on alert, where we need to be contacting patients and let them know that in your area, the flu is prevalent, and so you need to come in and get your flu shot now to make sure you’re protected. We use that data extensively to really alert people to take action.

Troy Trygstad, PharmD, MBA, PhD: One of the challenges for any practitioner in the health care system is the use, overuse, and proliferation of acronyms, and there’s no shortage of acronyms in the vaccine space. So, LAIV stands for what?

Brian Hille, BSPharm, RPh: Well, that is for the nasal-administered flu vaccine. So, that is the form that was actually off the market last year and was not recommended by ACIP.

Troy Trygstad, PharmD, MBA, PhD: And why was that the case?

Brian Hille, BSPharm, RPh: Well, they saw some variation in the coverage for patients, so how effectively it actually works. It is back to a recommended vaccine for the flu season that we’re coming up on.

Troy Trygstad, PharmD, MBA, PhD: So, we have 'L for live,' then we also have inactivated, and then, of course, we have a third category that isn’t live or inactivated but resembles the virus. Those are essentially our 3 categories.

Brian Hille, BSPharm, RPh: Yes, that’s right.

Troy Trygstad, PharmD, MBA, PhD: What’s your experience with those 3 categories, types of vaccines? It’s different for different disease states, obviously, and some are preferred in some circumstances and not in others. For those of us out in practice, obviously, we look at the ACIP guidelines pretty regularly. But it’s not uncomplicated, right?

Brian Hille, BSPharm, RPh: Yes, it has gotten much more complicated over the years. If you think about it, when I first got into giving flu shots, there was 1 flu shot and it was very generic, and now you’ve got populations of people where there’s maybe a little bit better vaccine specific for that population. But I should mention first, from ACIP’s perspective, just get your flu shot. And most importantly, make sure you get that dose. Then, once you get to the over-65 population, there are some studies that show some better effect from, like, the high dose or attenuated type of vaccine. You’ve got a newer vaccine that’s on the market that has some studies that show that it has some benefit for patients aged 50 to 65. And so, we do have a few vaccines that have kind of differentiated themselves from the others, and I think that’s why it’s so important for pharmacists to stay very current with what the studies are and what vaccines are available in the market place.

John Beckner, BSPharm, RPh: If I could just interject: It used to be with a limited number of vaccines on the market, limited number of manufacturers. You worried about supply issues from year to year. It has been a long time, Brian, since we’ve experienced a supply issue.

Brian Hille, BSPharm, RPh: Long time.

Troy Trygstad, PharmD, MBA, PhD: You mean in flu?

John Beckner, BSPharm, RPh: In flu, right. I’m sure we’ll get into some other vaccines later that are in short supply right now. That’s the good side. The conundrum, if you’re a practitioner, is knowing what to order and how much.