About My Health Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Mutation of H3N2 Virus Lowers Efficiency of Flu Vaccine

by Julia Samuel on November 9, 2017 at 4:46 PM
Font : A-A+

Mutation of H3N2 Virus Lowers Efficiency of Flu Vaccine

The low efficacy of the influenza vaccine against H3N2 virus can be attributed to a mutation in the H3N2 strain of the virus, a new study reports.

Due to the mutation, most people receiving the egg-grown vaccine did not have immunity against H3N2 viruses that circulated last year, leaving the vaccine with only 20 to 30 percent effectiveness.

Advertisement


Scott Hensley, PhD, an associate professor of Microbiology, in the Perelman School of Medicine at the University of Pennsylvania, describes his team's findings in the Proceedings of the National Academy of Sciences.

"Our experiments suggest that influenza virus antigens grown in systems other than eggs are more likely to elicit protective antibody responses against H3N2 viruses that are currently circulating," Hensley said.
Advertisement

"The 2017 vaccine that people are getting now has the same H3N2 strain as the 2016 vaccine, so this could be another difficult year if this season is dominated by H3N2 viruses again."

Flu vaccines work by priming the immune system with purified proteins from the outer layer of killed flu viruses. This induces immune cells to make antibodies that stop foreign invaders from infecting cells, readying them to attack flu viruses when the body sees them again.

Most flu vaccine proteins are purified from a virus grown in chicken eggs, although a small fraction of flu vaccine proteins are produced in systems that do not involve eggs.

During the 2014-2015 flu season, a strain of the H3N2 virus with a different outer layer protein emerged and this version of H3N2 remains prevalent today. The 2016-2017 seasonal flu vaccine was updated to include the new version of this protein; however, Hensley's lab found that the egg-grown version of this protein acquired a new mutation.

"Current H3N2 viruses do not grow well in chicken eggs, and it is impossible to grow these viruses in eggs without adaptive mutations," Hensley said.

The team showed that antibodies elicited in ferrets and humans exposed to the egg-produced 2016-2017 strain did a poor job of neutralizing H3N2 viruses that circulated last year. However, antibodies elicited in ferrets infected with the current circulating H3N2 viral strain (that contains the new protein) and humans vaccinated with a H3N2 vaccine produced in a non-egg system were able to effectively recognize and neutralize the new H3N2 virus.

"Our data suggest that we should invest in new technologies that allow us to ramp up production of influenza vaccines that are not reliant on eggs," Hensley said.

"In the meantime, everyone should continue to get their annual flu vaccine. Some protection against H3N2 viruses is better than nothing and other components of the vaccine, like H1N1 and influenza B, will likely provide excellent protection this year."

Source: Eurekalert
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Advertisement
News Category
What's New on Medindia
International Day of Persons with Disabilities 2021 - Fighting for Rights in the Post-COVID Era
Effect of Blood Group Type on COVID-19 Risk and Severity
Woman with Rare Spinal Cord Defect from Birth Sues Doctor
View all

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Chicken Pox Shigellosis Flu Swine Flu Vaccination for Children McArdle Disease Preventing Flu: Good Health Habits Can Help Stop Germs Top 10 Vaccine Myths Debunked How Do Viruses Mutate and Why Does it Matter? 

Recommended Reading
Bird Flu
Bird flu (avian influenza/avian flu) is a disease caused by an influenza virus (H5N1) that ......
Acute Bronchitis
Acute bronchitis is a short term inflammation of the bronchi of lungs. It is usually caused by a ......
Preventing Flu: Good Health Habits Can Help Stop Germs
How is the flu spread and how effective is flu treatment? Learn more about the influenza virus and ....
Chicken Pox
Chicken pox is an acute and highly contagious viral infection caused by the varicella zoster virus....
How Do Viruses Mutate and Why Does it Matter?
Mutations are the sudden changes that occur in genetic materials. They occur as a part of evolution ...
McArdle Disease
McArdle disease is a genetic disorder in which the body cannot breakdown glycogen in the muscles. It...
Shigellosis
Shigellosis or Bacillary Dysentery is a common cause of gastro-enteritis worldwide and can cause blo...
Swine Flu
Swine flu, a type of influenza caused by a new strain of the H1N1 Type A influenza virus has origina...
Top 10 Vaccine Myths Debunked
Childhood vaccination has saved many lives, yet lots more has to be done to increase awareness and e...
Vaccination for Children
Vaccines are biological products that impart immunity to the recipient. Vaccines may be live attenua...

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2021

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use