Can Chickens Get Coronavirus?

While chickens can get coronaviruses, the same viruses do not infect humans. Further, we have no evidence that chickens can get the coronavirus that causes Covid-19.

What is a Coronavirus?

Viruses are tiny pathogens, so small that millions can travel on a single spec of dust. Outside the cell of a living organism, however, a virus is basically dormant — it doesn’t eat or breathe, and can’t intentionally travel from one place to another. Its only known activity is to take over the cell of another life form for the purpose of making copies of itself.

Each virus consists of a strand of hereditary information, or genome, enclosed in a protective protein coat called a capsid. Some viruses, including coronaviruses, have an additional layer, called an envelope, that protects the protein coat. The envelope allows a virus to remain infective until it encounters a suitable living cell to invade.

Viruses are taxonomically organized into 26 families. Coronaviruses belong to the large family known as Coronaviridae. June Almeida identified the first member of this family in 1964.

Peering into her microscope, Ms. Almeida saw a virus covered by tiny knobby spikes that appeared to form a halo or crown. The word corona is the Latin word for crown.

The virus Ms. Almeida was trying to identify, which caused flu-like symptoms in humans, reminded her of a pathogen she had seen before. It was a virus responsible for causing bronchitis in chickens.

Avian Infectious Bronchitis

Avian infectious bronchitis in chickens was first observed in the United States in the 1930s. But the disease in chickens was not identified as a coronavirus until Ms. Almeida made her breakthrough discovery.

As described in The Chicken Health Handbook, infectious bronchitis is a common respiratory illness in chickens. It is also their most contagious disease. Infectious bronchitis starts suddenly and spreads rapidly. It causes coughing, sneezing, and rattling sounds in the throat. Deaths occur primarily in chicks.

Recovered chickens continue to shed the virus for several days, then develop temporary immunity. They can become reinfected as their immunity declines or some other strain of the same virus comes along.

Like the vaccine for human flu, the vaccine for avian infectious bronchitis bestows immunity only against the strains contained in the vaccine, and new strains keep evolving. The only sure way to rid a flock of infectious bronchitis is to get rid of the infected chickens. Then clean up, disinfect, and start over.

Similar avian coronaviruses infect geese, ducks, turkeys, guinea fowl, pheasants, peafowl, and pigeons. But “The coronaviruses in birds do not, according to all our current knowledge, infect humans. And we’ve had plenty of time since we’ve known about these viruses for us to see if that might happen,” says veterinary pathologist Beth Valentine, retired from Oregon State University College of Veterinary Medicine.

But Can Human Covid-19 Infect Chickens?

Before a coronavirus can infect a living cell, it must find a cell with receptors to which it can attach its spikes. A susceptible cell is one for which the receptor spikes on the virus’s envelope correspond with genetically determined compatible receptors on the cell’s membrane.

Based on differences in protein sequences in their genetic codes, coronaviruses are classified into four genera: alpha, beta, gamma, and delta. The viruses that mostly affect the cells of mammals, including humans, are alpha and beta. Those that affect bird cells are gamma and delta. SARS-Cov-2, the virus responsible for Covid-19, is a beta.

To confirm whether or not chickens can get this particular coronavirus, researchers at Germany’s Federal Research Institute for Animal Health inoculated chickens with SARS-Cov-2. They found that chickens are not affected by the Covid-19 virus.