How CDC Is Using Advanced Molecular Detection Technology To Better Fight Flu!

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Influenza ( influenza ) is a serious illness caused by influenza viruses. Influenza viruses are constantly changing. They are among the fastest mutant viruses known. These changes may affect the operation of the flu vaccine, or may also result in the emergence of new influenza viruses against which people have no pre-existing immunity, triggering a pandemic. Throughout the year, scientists from the CDC, the World Health Organization (WHO) and other partners monitor influenza viruses that infect people. These scientists are studying viruses in the laboratory to see how they evolve.

CDC uses next-generation gene sequencing tools to analyze influenza viruses as part of the CDC's Advanced Molecular Detection (AMD) initiative . The technology allows CDCs to study more flu viruses faster and in more detail than ever before. AMD technology uses genomic sequencing, high performance computing and epidemiology to study pathogens and improve disease detection. The CDC uses this next generation sequencing technology (NGS) to monitor genetic changes in influenza viruses to better understand and improve the effectiveness of influenza vaccines.

To share more information on this revolutionary NGS technology and its hard-hitting work, John Barnes, PhD, head of the Flu Genomics team of the Division of Virology, Surveillance and Diagnosis Division ] of the CDC participated in a Reddit Ask Me Anything digital survey to answer the public's question about AMD technology and how these tools help improve surveillance of the influenza virus and the development of better influenza vaccines . This message includes some highlights of this discussion.

Question 1: What exactly is the AMD technology platform that is different from the current approaches used to guide the development of vaccines? And what are the most common reasons why we "guessed" that viral strains would be responsible for the flu next season?

<img class="alignleft wp-image-9964" src="" alt=" Dr. Barnes After Reddit Ask Me Something Q & A "width =" 350 "height =" 290 "/> Dr. Barnes: An example of how AMD technology is used in the development of vaccines is that these mutations can alter the vaccine virus to the point that the immune response to vaccination does not protect against circulating viruses as well.CDC uses AMD technology to try to solve this problem. the genetic sequences of 10 generations of H3N2 virus during their growth and evolution in eggs Once the "good" genetic changes are identified, the CDC will synthesize the H3N2 viruses with properties that can be used to make a vaccine that offers better protection against H3N2 Infection.One of the main reasons why the virus is difficult, is due to its RNA polymerase. flu is very prone to errors and causes a rapid mutation of the virus. For example, some years, some influenza viruses may not appear and spread later during the influenza season, making it difficult to prepare a vaccine candidate vaccine in time for vaccine production. This can make the vaccine virus selection very difficult. We are currently using AMD techniques to sequence all clinical specimens that enter the CDC to improve our ability to find and track mutations that may be of concern.

Question 2: Why are chicken embryos generally used for influenza vaccine culture?

Dr. Barnes: Thanks for that question – that's the one we receive a lot! Influenza vaccines have been manufactured using an egg-based manufacturing process for over 70 years. In the past, when manufacturing a vaccine for production, manufacturers used eggs as a safe host for making the vaccine and providing high efficiency. Because birds are the natural reservoir of influenza, flu usually grows well in eggs and maintains a safe distance between the species you use to make the vaccine and the target. Mammalian cell lines have been subjected to extensive safety testing to establish a cell line free of human pathogens, while maintaining sufficient vaccine yield. You can find out more about how AMD technology enhances the development of flu shots using egg-based technology, here .

Question 3: What about the influenza virus that causes such a rapid mutation from year to year requiring a new vaccine each season? For example, in the case of chickenpox, there is a virus and a vaccine, so why, with the flu, are there innumerable strains and a new vaccine each year?

Dr. Barnes: As you know, influenza is a virus that can only replicate in living cells. Influenza viruses survive by infecting host cells, multiplying and then leaving host cells. The enzyme that the flu uses to copy itself is very prone to errors, which causes a rapid mutation of the virus. Each host has its own defense mechanisms and these defenses are collectively referred to as environmental pressures. It's hard to predict how a virus will mutate trying to get around a host's immune defenses, but changes can happen quickly, as you've said.

Because flu viruses are constantly changing, flu vaccine formulation is reviewed annually and sometimes updated to track the evolution of influenza viruses. More information on how influenza viruses can change is available here .

Question 4: Do you have an overview of the universal vaccine that was developed?

Dr. Barnes: Good question! Yes, I can give an overview. A longer-term goal for seasonal influenza vaccines is the development of a single vaccine, or universal vaccine, that provides safe, effective, and long-lasting immunity against a wide range of different influenza viruses (both seasonal). and new). At present, the CDC is part of an inter-agency partnership coordinated by the Advanced Biomedical Research and Development Authority (or BARDA) that supports the advanced development of new and better vaccines against influenza. These efforts have already yielded significant successes (ie, a high-dose flu vaccine specifically for people 65 years of age and older that creates a stronger antibody response), but part of this effort is the potential development of the vaccine. a universal vaccine. A number of government agencies and private companies have already started working to advance this type of vaccine development, but, as you can imagine, this task poses a huge scientific and programmatic challenge.

Question 5: How would you convince anyone who is resolutely against flu shots that they are a good thing?

Dr. Barnes: Help solve misconceptions about the flu. Remind people that a flu shot can not cause flu illness. They should understand that no one can catch the flu, and every year thousands of people in the United States die of the flu, and many others are hospitalized. It is important to note that influenza vaccine can prevent people from getting the flu, reduce the severity of the flu, and prevent them from transmitting influenza to their family and other people. who are likely to have serious complications.

Interested in learning more? See the complete Dr. Barnes Reddit AMA here .

John Barnes, Ph.D., is the team leader of the Influenza genomics (IGT) team at the Virology, Surveillance and Diagnostics Division of the Influenza Division of the Canadian Influenza Division. CDC. He earned his Ph.D. degree in Biochemistry and Molecular Biology from the University of Georgia in Athens, Georgia. Dr. Barnes began his CDC career in the Influenza Division in 2007 after working at a postdoctoral internship in the Department of Human Genomics at Emory University. His current job includes managing a staff of nine to meet the sequencing and genetic analysis needs of the flu division. The current number of viruses sequenced by IGT makes the CDC Influenza Division the largest contributor of flu sequence data among WHO collaborating centers for influenza.


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