H5N1 Bird Flu Virus – The Importance of Flu Vaccines
Avian influenza, more commonly referred to as "bird flu," is a virus that is often overlooked when we think of infectious diseases. It is a highly contagious respiratory disease that is caused by the influenza virus H5N1. Few human cases of H5N1 avian influenza exist, although human-to-human transmission of the illness is rare. Nonetheless, the mortality rate is roughly 60% when people do contract the disease.
The A(H5N1) strain of the highly pathogenic avian influenza (HPAI) virus is mostly found in birds, is extremely contagious among birds, and can be fatal, particularly in domestic poultry. Since December 2003, a HPAI H5N1 virus has caused substantial mortality in domestic poultry and wild birds in parts of Asia, the Middle East, Europe, and Africa. However, this virus was also discovered in a wild duck in the United States in January 2015. The HPAI H5N1 virus discovered in the United States contains a novel and unique avian influenza gene combination. It has genes from low pathogenic North American viruses and Asian HPAI H5 viruses, making it a reassortment virus (a new virus formed from the genetic combination of two distinct viruses). Although there haven't been any reports of this reassortment virus in humans, it's likely that it may infect people and possibly lead to a devastating disease.
Nearly all human occurrences of H5N1 infection have been linked to close contact with infected live or dead birds, or settings that have been contaminated with the virus. This makes immunizations vital. The CDC recommends individuals 6 months and older get a seasonal flu vaccine every year. It is critical that anyone who may come into contact with sick birds receive a flu vaccine, preferably two weeks before potential exposure. Annual flu vaccination can reduce the likelihood of contracting both the human and bird flu viruses at the same time.
It is important to note that there is not a specific vaccine for the bird flu, and existing seasonal flu vaccination is not guaranteed to prevent infection with bird flu viruses. Since human-to-human transmission is rare, there is little need for concern. That being said, seasonal flu shots can lessen any risks from the H5N1 virus. A(H5N1) and A(H7N9) bird flu vaccines are being developed by the U.S. government in case they are required for potential epidemic emergencies. If viruses of a similar nature begin to rapidly spread, these vaccines may be utilized. The first stage in making a flu vaccination is developing a candidate vaccine virus, or CVV. The CDC continues to produce these as needed, since flu viruses evolve often.
For more guidelines on prevention and antiviral treatment of bird flu viruses in people, please make sure to check out the guidelines put out by the CDC here.
