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FDA Insight: Get Your Flu Vaccine

On this week's episode, Dr. Shah brings Dr. Peter Marks back to the show to discuss the importance of getting the flu vaccine. For more information about the flu vaccine, visit: https://www.fda.gov/flu

FDA Insight: Episode 17 – Transcript

>> Anand Shah: Welcome back to another episode of FDA Insight. I'm Dr. Anand Shah, the Deputy Commissioner for Medical and Scientific Affairs here at the FDA. Thank you so much for joining us for another great episode. This week, we'll be discussing this year's flu season and the importance of getting vaccinated, which is especially important as we continue the fight against the COVID-19 pandemic. My guest today is Dr. Peter Marks, Director of the FDA's Center for Biologics Evaluation and Research, who by now, is very well known to many of our listeners. Dr. Marks, thanks for coming again today to talk about vaccines – and this time discussing the flu.

>> Peter Marks: Thanks, I'm glad to be back again.

>> Anand Shah: Well, let's jump right in. COVID-19 has disrupted standard medical care and priorities and routine treatments, why is it so important for consumers to receive a flu shot this year?

>> Peter Marks: Well, most importantly, the flu vaccine lowers the risk of hospitalization or complications related to flu-like pneumonia. And, if you're vaccinated but later catch the flu, it's more likely that the flu will be mild and treatable at home. So, not having to go to the hospital, also reduces your potential exposure to COVID-19 and it saves resources that are needed for COVID-19 patients. And finally, COVID-19 presents greater risk if you have certain underlying health conditions that compromised, reduce your immune system's response. And if you're actively fighting the flu, you could be more vulnerable to COVID-19 and it's actually possible that one could have both viruses at once.

>> Anand Shah: Are there any interactions between the flu and COVID-19 based on the data or experiences of other countries?

>> Peter Marks: Well, we don't yet know a lot about the interaction between flu and COVID-19, in part due to something relatively positive. So many more people than previously in certain places in the southern hemisphere, like Australia, got the flu vaccine and so they had very mild seasons for flu there, which is a good thing. There's also some early, yet intriguing evidence, that people who have been vaccinated against influenza seemed to have a somewhat lower chance of getting COVID-19.

>> Anand Shah: Dr. Marks, can you tell us about the flu vaccine? How does it work? And, is the flu vaccine effective against all strains?

>> Peter Marks: Well, I'll start by kind of backing up and telling you that the body fights off viruses, like influenza, by generating an immune response. This involves the immune cells of the body, called T and B lymphocytes. The vaccine then works by triggering those immune cells to produce a response that includes the production of antibodies that can help the body prevent infection with the flu. There are many different strains of influenza and the ones that circulate can change over time. And that's why the composition of the flu vaccine changes from year to year or at least for some of the strains that are in the flu vaccine. Influenza A and influenza B caused disease both in adults and children; however, influenza B tends to cause relatively more complications and fatalities in children than in adults. All inactivated flu vaccines, though, contain at least three flu strains that they protect against, two influenza A strains and one influenza B strain. And these are called trivalent vaccines. And, many vaccines now contain a total of four strains, two A strains and two B strains and these are called quadrivalent vaccines. The second B strain is particularly useful for helping to protect children. There are also special flu vaccines that are available for individuals who are 65 years and older, who typically bear the brunt of severe influenza disease and account for most influenza-related hospitalizations and deaths. These vaccines contain either high doses of the inactivated virus or it contained a kind of immune stimulant called an adjuvant that helps that body better produce antibodies or immune responses in response to the vaccines. Though the flu vaccine might not be fully effective in preventing all of the circulating flu strains in a given year, it's clear from past experience that even when it doesn't prevent the flu, it might lessen its severity. So, getting the flu shot is still a good idea.

>> Anand Shah: Dr. Marks, how is the flu vaccine actually made?

>> Peter Marks: So, each seasons' flu vaccine takes about six months of laboratory work and manufacturing to make and most of the vaccine that's used in the United States is made using and egg-based production process. While the egg-based production process method produces safe and effective vaccines, FDA, HHS and manufacturers have been working on different technologies to increase the influenza vaccines' supply, while maintaining its safety and effectiveness. And one example is that more recent approvals include influenza vaccines that don't use and egg-based production process for manufacturing. They either grow the cells that make the virus in cell culture. They use mammalian cells in cell culture, or they produce the relevant influenza proteins by making use of newer methods in biotechnology.

>> Anand Shah: How are flu vaccine virus strains selected for each season's vaccine?

>> Peter Marks: So, each February, before that year's flu season ends, the FDA, World Health Organization, CDC, and other public health experts collaborate on collecting and reviewing data from around the world to identify flu viruses likely to cause the most illness during the next flu season. Then the FDA convenes its vaccines advisory committee, which consists of outside experts to provide advice to the FDA on the upcoming U.S. influenza season. In addition to the WHO recommendations, the – our advisory committee considers which flu viruses they expect to circulate in the United States and they also review data about which flu viruses caused illness in the past year, how the viruses are changing, and the disease trends for the United States.

The FDA then takes all of this information into account before selecting the virus strains for use in the FDA-licensed flu vaccines that manufacturers will make for the United States. The closer the match between the virus strains chosen for the vaccine and circulating strains that year that caused disease during flu season, the better protection the flu vaccines will provide. And, although the vaccine and viruses may not be an exact match in some years, that doesn't mean that the vaccine is not benefitting people. We know, again as I mentioned somewhat before, that past studies have shown that vaccine can still provide enough protection in people who received it to make their illness milder or prevent flu related complications.

>> Anand Shah: What's the process for ensuring these vaccines are actually safe?

>> Peter Marks: Well, first and really importantly, I want to assure listeners that FDA takes the greatest care to ensure that vaccines – that is all vaccines licensed in the United States – are as safe as they possibly can be. Influenza vaccine and influenza vaccination is very rarely associated with serious adverse effects and every year it's likely responsible for saving tens of thousands of live. So, the benefit-risk is far in favor of receiving the vaccine. When new types of influenza vaccines are developed, like any other new vaccine, development begins in the laboratory before conducting animal-human testing. If laboratory tests show that a vaccine has potential, it's usually tested in animals first and if further studies suggest it will be safe in people, human clinical trials are the next things that are done.

Typically, there are three phases of clinical trials and FDA sets stringent guidelines for the three phases to ensure the safety of volunteers. And, you can read more about process by searching FDA vaccines product approval process on your browser. And in addition to the extensive testing that vaccines undergo, the FDA has safeguards to monitor for any issues that may arise in vaccine programs that are being administered to people during the yearly influenza campaigns and these include FDA Sentinel Initiative which was launched in 2008 and this established a national risk identification and analysis system, using electronic health care data to monitor the safety of drugs, biologics and devices. We also, under the National Childhood Vaccine Injury Act, health care providers and vaccine manufacturers have to report adverse events following the administration of vaccines. And, finally, under FDA regulations, the licensed vaccine manufacturers have to report adverse experience information to the FDA as well. So, there are overlapping protections.

>> Anand Shah: As doctors, we encourage many people to get vaccinated, children and elderly, men and women. Who's most at risk of getting the flu?

>> Peter Marks: So, typically it's children and older people that are most at risk of getting sick with influenza. And to protect babies, who are too young to be vaccinated, is to make sure that people around them are vaccinated. The good news is, if you're protecting yourself from COVID-19 by wearing a facemask in public, frequently washing your hands, covering coughs and sneezes and staying home when you're sick, you're already helping to reduce the spread of flu and helping keep high-risk individuals healthy.

>> Anand Shah: Speaking of high-risk individuals, who should not receive the flu vaccine?

>> Peter Marks: Well, for the 2020-2021 flu season, CDC's Advisory Committee on Immunization Practices, the ACIP, recommends annual flu vaccination for everyone six months and older with any licensed influenza vaccine appropriate for that recipients' age and health status. The flu vaccine is very safe and more that 150 million people in the United States receive one annually without any adverse reaction. However, some people should ask their physician about the vaccine, particularly if they've ever had an adverse reaction to a vaccine because that may help their doctors choose an appropriate vaccine for them against influenza. And, there are many vaccine options to choose from but the most important thing, is for all people six month and older to get a flu vaccine every year.

>> Anand Shah: Dr. Marks, what would you say to someone who says they don't need the flu vaccine because they're staying at home due to COVID-19, and limiting exposure to individuals outside their family?

>> Peter Marks: Well, first of all, nothing is absolute. Social distancing and exposure limitation aren't guaranteed to keep you from getting the flu. These are steps that are just part of a plan to stop the spread of the virus. It's best to combine vaccination with social distancing and other physical measures to protect yourself and your family. And, the second is that flu seasons and their severity are unpredictable. Annual vaccination is the best way to prevent influenza and stop its transmission to others. When more people get vaccinated, it's less likely that the flu viruses will spread through a community.

>> Anand Shah: Dr. Marks, if a person has a question about the flu vaccine, where can they go for more information?

>> Peter Marks: Well, for personalized advice about the flu vaccine, individuals can consult their medical providers. Otherwise, if somebody wants to get general information, they can go to FDAs' website at https://www.fda.gov/flu or the center for disease controls' website, which is https://www.cdc.gov/flu.

>> Anand Shah: What other advice do you have for the public?

>> Peter Marks: Well, one of the more common things we have is that some people are worried that they may get the flu from the flu shot. Although the flu vaccine will trigger your immune system to produce antibodies and immune cells that can protect against influenza disease, it can't make you sick with the flu. Also, it can take about two weeks after vaccination for the flu vaccine to be effective, which is an important reason for you to get your flu vaccine before there's any significant flu activity circulating in the community.

>> Anand Shah: Dr. Marks, you've provided great information about the flu. And, as a fellow doctor, I join you in encouraging people to get the flu vaccine this year. Thank you for taking the time to join us this week on FDA Insight.

>> Peter Marks: Thanks so much for having me back again and I hope that you'll still have me back again in the future.

>> Anand Shah: Absolutely. Coming up on our next episode, we'll be talking about hand sanitizers, so be sure to tune in for that. As always, we'll provide you insight in plain language to help you understand the products that we regulate, the issues that we face and the processes that we follow. We hope you enjoyed this episode of FDA Insight. Please subscribe on your favorite podcast app such as Google Podcasts, Apple Podcasts, Spotify and Pandora. Thanks for listening.

[end of transcript]

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