Much like their human brothers and sisters, dogs can catch the influenza virus and spread it to their furry friends. And now researchers are working on improving the vaccine that could protect them from the flu.
A team from the University of Rochester in New York is currently exploring how they can make live-attenuated influenza vaccines for dogs.
History Of Canine Flu Shots
In the United States, the first canine flu vaccine was green-lighted in 2009, or around five years after the first canine-specific strain was found in Florida racing greyhounds and thousands of other dogs of other breeds in different states, Newsweek reported.
Veterinarian Cynda Crawford, who helped discover the strain, said the H3N8 canine influenza virus took off from an equine strain that has been infecting horses since the 1960s. A different strain, H3N2, was adapted from an avian influenza and appeared in Chicago back in March 2015.
For both flu strains, the currently available vaccines are killed, meaning they contain a dead virus. Two shots that are a couple of weeks apart are required, along with a recommended booster for every following year.
But there’s one problem.
“Nobody likes needles, including dogs,” said professor Martinez-Sobrido, who led the discovery of the team as well as other researchers from Cornell and University of Glasgow on how to make modified live influenza vaccines for dogs, or live-attenuated canine influenza vaccine.
In their first study, the team introduced five mutations to the H3N8 virus used for creating the live vaccine for influenza in humans, including the nasal spray FluMist taken in one rather than multiple doses. As a result, the mouse subjects demonstrated a stronger immune response and were guarded against subsequent infections better than those receiving a dead or inactivated vaccine.
In their second paper, the group completely deleted and performed other actions on the NS1 protein in the virus. This process has been tested in swine, equine, and human viruses in order to produce immune responses without unintentional sickness.
Tweaking The Flu Vaccine For Dogs
Similar experiments are being conducted to develop live vaccines for the H3N2 virus in dogs, which Crawford added has more quickly spread and infected thousands of dogs in about 30 states in less than two years.
The results are deemed promising, although the U.S. Department of Agriculture is expected to be rigorous in its approval.
The reason: flu viruses are known to be quick in gene sharing, which could pave the way for a new virus that can infect both canines and humans or lead to a more serious problem. With a live vaccine, dogs are more prone to becoming “mixing vessels” if they contract human influenza, which they can be infected with but not spread, around the period of vaccination.
The Centers for Disease Control and Prevention recently disclosed that the flu vaccine for the 2016-2017 season protects around half of individuals from infection — not as satisfactory as last year’s formula, but better than in some previous years.
The flu has killed 20 children so far into the season, and the virus is still considered widespread. Influenza activity will likely continue for a few more weeks in the country, and vaccination should continue as long as the viruses circulate, the federal agency noted.