If you’ve ever had the flu, you know how tired, achy, and miserable it can make you feel. Sometimes staying healthy during flu season just isn’t enough to fend off the influenza virus. Several different strains of flu viruses circulate each year, and influenza vaccines are one of the best proven ways to prevent flu and its complication. In response, the National Institute of Allergy and Infectious Diseases (NIAID) laboratories develop new vaccines and vaccine technologies for seasonal flu viruses and animal strains that could become pandemics.
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The influenza vaccines now used in the United States are safe and effective at preventing flu and its complications. But, did you know that the flu virus used for influenza vaccines is grown in chicken eggs? The process requires a large supply of fertile chickens and eggs and is dependent on how well the virus grows in the eggs. Influenza vaccines are altered based on the virus, and the chicken and egg process makes it difficult to accelerate vaccine production during an influenza pandemic. This was apparent in the 2009 H1N1 influenza pandemic when accelerated vaccine production was needed, but the virus was slow to grow in eggs.
Trivalent Influenza Vaccines
In January of 2013, the U.S. Food and Drug Administration announced that it had approved Flublok, the first trivalent influenza vaccine made using an insect virus expression system and recombinant DNA technology. Unlike the current flu vaccines, Flublok does not use the influenza virus or eggs in its production. This difference in manufacturing technology allows for the production of large quantities of the active ingredient in all inactivated influenza vaccines that allows for entry of the virus into cells in the body. The technology is new to flu vaccines, but it has been approved in the past by the FDA to prevent other infectious diseases.
An adjuvant is a substance added to a vaccine to lessen the amount of antigen needed and boost the immune response. This higher amount of antibodies and longer lasting protection minimizes the amount of injected foreign material. Adjuvants used in influenza vaccines are known to widen the reach of the immune response so that there is more cross-reactivity. People vaccinated with these types of vaccines often have more soreness in the arm at the site of injection and a fever because they cause an inflammatory immune response. Adjuvants are constantly being studied by NIAID-supported researchers for improvements and new technologies that could help with the flu virus.
Optimizing Delivery Methods
Optimizing delivery methods is a focus for all the new vaccines and vaccine platforms NIAID is exploring. They are currently researching a “gene gun” which would deliver vaccine directly into a person’s arms and a “bacterial ghost” which are membranes where DNA could be inserted. The DNA would then travel to a person’s lymphoid tissue and be ingested by the cells there, stimulating an immune response. The NIAID is constantly improving the manufacturing and testing process for new flu vaccine platforms as well.
As technologies geared toward improving flu prevention are continuously researched and put into place, the flu season future is looking brighter for those prone to catching the bug.