CDC’s Flu Czar Says She’s Ready for the Fall Offensive

Did you see much influenza this year? Neither did anybody else. That’s because mitigation measures used to fight COVID-19—hand hygiene, masking, social distancing—might have been only somewhat effective against SARS-CoV-2 (or perhaps not applied with enough effort, many medical experts would argue), but they stopped the flu. Does that present a problem for the coming 2021-2022 flu season as government officials ease up on those measures? Not really, says Lynnette Brammer, who heads the Domestic Influenza Surveillance team at the Centers for Disease Control and Prevention (CDC). True, the vaccines that will be used to fight the flu this fall are already being manufactured, and those vaccines, as is the case with flu vaccines each year, are created based on the previous year’s flu data—of which, as mentioned, there’s a dearth. “We haven’t had as much data as we have had in previous years, but we did still have a good bit of data,” Brammer tells Infection Control Today® (ICT® ). In addition, fighting COVID-19 greatly improved the health care system’s surveillance capabilities when it comes to respiratory diseases. That and a huge influx of funding to improve state public health departments, along with technological and systemic innovations created because of COVID-19, will keep flu manageable, Brammer says. Still, she warns that “the diagnosis of respiratory disease this coming fall will probably be a little bit more complex than it was over the past year.”

ICT®: Will influenza cause us a lot of problems in the fall?

Lynnette Brammer: Flu can cause lots of problems every fall. We say all the time—and I know people get tired of hearing it, but I think right now it’s truer than ever—that flu is incredibly unpredictable. Just in a regular year there can be huge variation in how severe flu season is. And the upcoming one will be no different. It could be severe or it could be a mild flu season; we don’t know. But there’ll be a lot of new factors at play this coming year.

ICT®: Such as?

Brammer: We’re coming off all these mitigation measures, which did do a really good job at combating flu. We’re starting to loosen up on those—[for instance], the mask wearing for people that are vaccinated against COVID-19. And we’re starting to get together with our families again. Eventually, we’ll start domestic and international travel again, I assume, and, you know, all those things….And the kids will go back to school in the fall. And all of those things will have an impact on flu virus circulation.

ICT®: Can you walk through the process of developing the flu vaccine each year?

Brammer: Well, it’s done in this collaborative, worldwide process. We work with the World Health Organization to participate in international surveillance for influenza. Countries across the world collect specimens from people with respiratory illness and test them for influenza. And then the

Lynnette Brammer, heads the CDC's Domestic Influenza Surveillance team

positives—a subset of those go on to specialized centers around the world where more detailed characterization of the viruses occurs. We see what they look like. We look at people who’ve been vaccinated—their responses against those viruses that look a little bit different. We look at the vaccine effectiveness for the current year against those viruses and decide what viruses look like: No. 1, they’re spreading and have a chance to become a predominant virus; No. 2, which one of those you might not be protected against with the current vaccine components. And from that, they’ll then decide: “We think we need to update this component or that component.” There are always 4 in the vaccine. There are 2 influenza B’s and 2 influenza A’s. And these decisions are made in February, late February, early March. And the vaccines are produced and start getting distributed in the very late summer months and are administered in the fall.

ICT®: Do we have enough data to figure out what we can expect from the flu
this year?

Brammer: We haven’t had as much data as we did in previous years, but we did still have a good bit of data. There weren’t a lot of influenza viruses circulating anywhere, but there were some. And what we saw back…I guess it was back in late fall. In some areas of the world, as they started to loosen up some of their mitigation measures, [such as mask wearing], they started to see flu outbreaks. And so we had access to those viruses and have looked at those. And we looked at the antibody responses people made against last fall’s flu vaccine and tested it against those viruses to see if it looked like they would cover or not.

ICT®: Relatively speaking, how much less data do you have this year as opposed to any other year?

Brammer: I don’t know. I don’t remember the numbers well enough to know exactly how many viruses were looked at. But we feel like it’s not so much the number that you look at. When there’s very little out there, there’s less to see. If you think of it as a proportion of what’s out there, I think we saw as much or maybe even more of what was out there. It was just so little [has been] seen. You’re not missing anything if the viruses aren’t circulating. Because of this huge international network, we feel like we’ve got a really good representation of the viruses that were circulating.

ICT®: Because there’s so little data, does that call into question what conclusions health experts reached?

Brammer: I don’t think so. Because, yes, there were fewer viruses, but those are the viruses that are there, and those are the viruses that will give rise to the viruses that circulate, you know, if they do, in the coming fall.

ICT®: What is different about this year? What has changed?

Brammer: Oh, a lot has changed. In a lot of ways, flu and SARS-CoV-2 viruses are similar enough that our surveillance systems can be pretty similar. As we’ve expanded surveillance for COVID-19, surveillance for flu is improving, too. All the investment being made in state public health departments and public health laboratories—it’s a huge advantage for COVID-19. But it’ll be a huge advantage for flu, too. We are adding new surveillance pieces. There will be some new electronic data that becomes available to us. We’re hoping to have a more robust surveillance—high alert, at least in emergency departments—our hospital emergency department syndromic data. We’ve worked with our colleagues over in T cells at CDC,¹ and that network is expanding. We’re going to have much more robust data and a much better geographic coverage. That will work for COVID-19, but it also works for flu. We’re getting a lot more data and we learned a lot. We always had talked about being prepared for an influenza pandemic and being able to scale up our systems. COVID-19 scaled up our systems way more than we ever dreamed about scaling up for. But now we’ve got systems that can handle really large volumes of data. And that’s going to be really nice. Flu will certainly benefit from those improvements. We’ve found some of our systems didn’t work as well as they had in the past because health care–seeking behavior had changed. That has led us to think a lot about this: “If people change where they go for health care, how do our surveillance systems react so that we can continue to monitor?” In the coming years—not all in 1 year, but in the coming years—we’ll continue to evolve our surveillance systems to deal with some of the unanticipated issues that we saw over the past year.

ICT®: Last year, infection preventionists and other health care professionals were worried about emergency rooms being filled with people who had respiratory illness and they weren’t going to be able to tell whether they had influenza or COVID-19. That did not really materialize.

Brammer: Right.

ICT®: Is that still a possible problem that you have to deal with this coming flu season? Do they have flu? Or do they have COVID-19?

Brammer: I think it will be an issue that people are going to have to deal with this fall. I mean, as mitigation measures loosen up, we’re starting to see some of the other respiratory viruses begin to circulate again at a little bit higher level; so far, not flu, but some of the others, but flu will follow. And last year the diagnosis was easier, because almost all the respiratory illness was due to one thing, and that probably isn’t going to be the case for much longer. We’ll have to see. But it does look like some of the other respiratory viruses are coming back. We expect flu will come back. It’s just a matter of how quickly. But, again, some of the things that happened in the last year will help us. There’s more testing available. There are some of these multiplex tests that will test for flu and SARS-CoV-2 and respiratory syncytial virus. The tools will be there.²

ICT®: Can you talk a bit more about the multiplex test?

Brammer: There have always been these multiplex respiratory panel tests that had multiple respiratory viruses on them. They were less available in point-of-care sites—doctors’ offices, emergency departments, perhaps. But now there are some that are point-of-care multiplex tests. Public health labs have a multiplex test for flu and SARS-CoV-2. So, there are more tools available to more people.

ICT®: Have things been invented because of COVID-19 that you can now use during flu season?

Brammer: Yes, I think just across the board. Like I mentioned earlier, our ability to handle large amounts of data at CDC is improving every day. It has gotten much better. We’re getting new assays that are available. The financial support that’s coming to state public health is going to be hugely helpful. The public health system in the country had been underfunded for a long time, and now they’re getting a lot of money, and that infrastructure is being rebuilt. That’s going to be an advantage for COVID-19, for flu, for all of public health.

ICT®: You mentioned improvements in surveillance systems. Can you provide an idea of what that might look like on the ground?

Brammer: Let me think of some good examples: just simple things, like we monitor influenza-like illness through ILINet,³ which is our system for that. We’ve added about 1000 new providers. The National Syndromic Surveillance Platform, which collects syndromic surveillance data, which we use in ILINet4—they're now pushing to have all hospitals participate in that. That’ll be a huge advantage. We had it in the majority of states, but there were a couple of states still that were really underrepresented. That’s going to basically help us fill these gaps that we had beforehand. And then we’re working with new partners to get additional data sources—electronic health record data and a lot of new sources of data that we just didn’t have available to us in the past.

ICT®: Is there anything else about the coming flu season or how infection preventionists need to react to it that you would like to add?

Brammer: I think—and I’m sure they’ll be acutely aware—that the diagnosis of respiratory disease this coming fall will probably be a little bit more complex than it was over the past year. But there are these new assays out there that can be useful. And we expect that there are more resources for the states to do surveillance. They will have better surveillance data on which they can depend to help make treatment decisions.

References:

1. Department of Health and Human Services, Centers for Disease Control and Prevention, American Academy of Family Physicians, American Academy of Pediatrics. Understanding how vaccines work. Website. Last updated July 2018. Accessed June 8, 2021. https://www.cdc.gov/vaccines/hcp/conversations/downloads/vacsafe-understand-color-office.pdf
2. Centers for Disease Control and Prevention. CDC’s influenza SARS-CoV-2 multiplex assay and required supplies. CDC. Last updated February 2, 2021. Accessed June 7, 2021. https://www.cdc.gov/coronavirus/2019-ncov/lab/multiplex.html
3. Centers for Disease Control and Prevention. A weekly influenza surveillance report prepared by the influenza division: Influenza-like illness (ILI) activity level indicator determined by data reported to ILINet. CDC. Updated weekly. Accessed June 8, 2021. https://gis.cdc.gov/grasp/fluview/main.html
4. Centers for Disease Control and Prevention. National Syndromic Surveillance Platform. CDC. Accessed June 8, 2021. https://www.cdc.gov/nssp/index.html

This interview has been edited for clarity and length.