Transitioning to Trivalent Flu Vaccines: A Look at the Rationale and Counseling Strategies

Announcer Introduction

You’re listening to VacciNation on ReachMD, and this episode is sponsored by CSL Seqirus. Here’s your host, Dr. Charles Turck.

Dr. Turck: 

This is VacciNation on ReachMD, and I'm Dr. Charles Turck. Here with me today to discuss the rationale behind the global shift to trivalent flu vaccines is Dr. Christina Madison, who's the founder and CEO of the Public Health Pharmacist. Dr. Madison, thanks for being here today.

Dr. Madison:

Thank you so much for having me to talk about this very important topic.

Dr. Turck: 

Well, for some background, the World Health Organization and the Vaccines and Related Biologics Products Advisory Committee recently recommended transitioning from quadrivalent to trivalent flu vaccines that exclude the B/Yamagata lineage. So to start us off, Dr. Madison, would you tell us about the epidemiological data that helped inform this recommendation?

Dr. Madison:

Absolutely. So as most of us know, our vaccines are based on what we think the circulating strain will be for that particular flu season. And so the recommendations of the committee came based on the fact that the Yamagata/B strain hasn't really been circulating for the past three to four years. So even though we have had a version of the flu vaccine that has been quadrivalent for about the last 10 years, the committee really felt like it wasn't necessary to include that additional B component because of the fact that that is likely not going to be the case to be that circulating strain in the 2024-2025 season.

Also, there was a global shift that we wanted to unify the same vaccination for everyone, so not just here in the U.S., but in Europe and across the globe. And so this was something that the WHO thought we could do in the 2025-2026 season. But here in the U.S., it was really felt that that was something that we could switch to sooner and not have an unnecessary component within the vaccine formulation that was not needed, given the fact that the vaccine right now covers the three main strains that we think are likely to be circulating in the 2024-2025 flu season. And this was done during their meeting this past March.

Dr. Turck:

And how did other considerations like the overall prevalence of flu strains and the effectiveness of past vaccines also contribute to this decision?

Dr. Madison:

As you are very aware I'm sure, the flu vaccine formulation is a bit of a moving target. So every year, we tend to come up with what we think the circulating strain will be based on what is happening in a different hemisphere. So we know that based on those recommendations, we feel that this is going to be the best formulation for what we expect to occur. And with that being said, we know that sometimes we get it right, and sometimes we definitely don't get it right.

So the key here is to really base this on the epidemiologic trends, antigenic shift and drift, and ultimately, the disruption that we saw during the COVID-19 pandemic, which really is how we've decided to make these changes. Because we didn't see a traditional flu season for many years because of the disruptions that were seen during the COVID-19 pandemic and also from universal masking because there were several people that didn't get infected because of the fact that we saw people masking due to COVID.

Dr. Turck: 

Now given the reasoning behind this global recommendation, what kind of impact do you think this might have on vaccine efficacy and public health outcomes?

Dr. Madison:

So ultimately, simplification is always a good thing. When we can make things uniform and we can make things simple and easy for providers, they don't have to worry about things like, “Do I give quadrivalent to this group or trivalent to this group?” I think it just makes it very easy for us to make that simple decision to vaccinate our patients. And so it’s from an efficacy standpoint—obviously the fact that we're not adding a component to the vaccine that is not necessary due to the fact that we have not seen that additional B strain really circulating during the last three to four flu seasons. So that's also part of this decision-making factor as well as the consistency and making things just really easy for the providers to make that decision. 

Dr. Turck:

For those just tuning in, you're listening to VacciNation on ReachMD. I'm Dr. Charles Turck, and I'm speaking with Dr. Christina Madison about the global shift from quadrivalent to trivalent flu vaccines.

So now that we have a better understanding of why we're transitioning to trivalent flu vaccines, let's focus on how we can best apply these recommendations to practice. Dr. Madison, what counseling strategies do you recommend to help our colleagues address patient concerns about this update or flu vaccines in general?

Dr. Madison:

So one of the things that I see every year during the flu season, especially in my more senior population, is that they typically will ask, “So what is in the flu vaccine this year?” And so for those seniors that are always curious about what's in the vaccine—because they will be there, and they will have their sleeves rolled up ready to go to get their vaccine—is to be able to explain to them in a very meaningful way that the change to the vaccine is based on what we think the most likely circulating strain of the virus is going to be for this fall and winter. And so the key here is letting them know that three of the components of the vaccine have not changed, that they are going to remain the same, and that only one component of the vaccine was removed in order to deal with the fact that that strain is no longer circulating and hasn't been for the last three to four years. So that's how I would explain it to the patients, especially those seniors who are always curious about what's in the vaccine.

Dr. Turck:

And from your experience, how else can we promote informed vaccination practices in our patients?

Dr. Madison:

The key here is that universal recommendations are always going to be in place. So although we may have changed the formulation, it does not change who is recommended to receive the flu vaccine. 

Dr. Turck:

Well, we've certainly covered a lot of ground today, Dr. Madison. So before we close, what key takeaways would you like to leave with our audience?

Dr. Madison:

It's always wise to immunize. And make sure that you are having the conversation about vaccine confidence with your patients at every opportunity possible. And even if they choose not to get vaccinated at that visit, continue to remind them; you never know, they may get it the next time.

Dr. Turck:

Well, with those key takeaways in mind, I want to thank my guest, Dr. Christina Madison, for joining me to discuss the rationale behind the global transition from quadrivalent to trivalent flu vaccines. Dr. Madison, it was great having you on the program.

Dr. Madison:

Thank you so much for having me.

Announcer Close

This episode of VacciNation was sponsored by CSL Seqirus. To access this and other episodes in our series, visit VacciNation on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!