A world-renowned expert in coronaviruses, Dr. Baric (UNC’s Gillings School of Global Public Health) stated in the press release, “So this is not a situation of ‘if ’ there will be an outbreak of one of these coronaviruses but rather when and how prepared we’ll be to address it.”
It certainly wouldn’t be the first time that a SARS virus crossed over that barrier guarding human health from animal. In 2003, the SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus) crossed over from animals to humans. In fact, that highly progressive virus that had flu-like symptoms that grew worse and worse, infected 8,000 people, and 800 died.
The last reported cases were in 2004, thanks to “public health intervention” in containing the virus. In fact, the “original virus” had been dubbed “extinct”. Yet, that doesn’t mean the virus couldn’t re-emerge and that’s exactly what the discovery of the new SARS virus demonstrates (2).
New SARS Virus Hasn’t Crossed Over to Humans – Yet
The good news is that so far the SHCC014-CoV [SARS] virus found in Chinese horseshoe bats hasn’t crossed over to humans. Until it does, scientists won’t know if the virus can be transmitted from one human to another.
The bad news is that currently there are no treatments available if the virus does jump across species.
Like the original SARS virus, the new virus SHCC014-BaricCoV’s primary target for infection is the lungs where it easily sets up shop and replicates itself. Dr. Baric stated, “This virus is highly pathogenic and treatments developed against the original SARS virus in 2002 and the ZMapp drugs used to fight Ebola fail to neutralize and control this particular virus.”
More good news is that the research that identified the virus also presents the opportunity to create medicine and/or vaccines before the threat becomes real. Yet, that’s not so easy.
According to Baric, the scientific community needs to be “building resources, rather than limiting them.” He’s referencing the cut in government funding for this type of experiment. Baric reminds how important it is to search for new health threats to humans from the animal world, as well as to develop medicines. He says, “…therapeutics is key for limiting future outbreaks.”
This latest research fuels the “ongoing debate over the government’s decision to suspend all gain of function experiments on a variety of select agents earlier this year.” This change has, according to researchers placed a “substantial standstill on the development of vaccines or treatments” for this type of pathogens in preparation for potential outbreaks.
Just how would this new SARS virus cross over to humans?
The process of animal disease transmission to humans is known as zoonosis. For example, the Ebola virus as well as influenza are zoonoses. One form of transmission from animal to human can be done through direct zoonosis. This process can occur through air transmission such as flu. Other direct contact can be through saliva or bites, such as rabies (3).
The other form of transmission is called vector. This occurs when another species, an intermediate, is responsible for the transmission. A clear example would be how a mosquito can transmit the West Nile virus, ticks transmitting Lyme disease or birds carrying the avian flu.
In the news release, Baric explained that some of the 5,000 “predicted” existence of Coronaviruses within the bat population could have the “…potential to emerge as human pathogens.”
As senior author of a paper published in the Nature Medicine journal (November 2015), Baric and his team write, “Using the SARS-CoV reverse genetics system2, we generated and characterized a chimeric virus expressing the spike of bat coronavirus SHC014 in a mouse-adapted SARS-CoV backbone” (4).
These results demonstrated that virus replicates in human cells and with the potential to produce “epidemic strains of SARS-CoV.”
The study concludes that, “Our work suggests a potential risk of SARS-CoV re-emergence from viruses currently circulating in bat populations.”
References & Image Credits:
(2) TSW: WHO Warns about a Dangerous New SARS-like Virus from the Middle East
(3) Wikipedia: Zoonosis