Ebola, swine flu, and other viruses have received a lot of publicity for having crossed species to become deadly for humans. Another cross-species infection that flared up more in the past few years was Middle East respiratory syndrome (MERS), an illness that spread from camels to humans, affecting more than 1,600 people and killing 584 (about 36 percent), according to the World Health Organization (WHO). However, there is hope that once the current spread of the deadly virus is eradicated, a new MERS vaccine for dromedary camels may stop the illness from recurring at its source.
The proposed vaccine, which was developed by German scientists, has been effective in protecting dromedary camels against the virus that causes MERS. The vaccine being tested was designed to reduce nasal excretion of the virus, which would preclude transmissions of the infection from animal-to-animal or animal-to-human. (The virus is spread through contact with the body fluids, including nasal secretions, from infected mammals.) In dromedaries and other camels, the virus lodges in their upper respiratory tracts. The animals develop a mild infection, which, like a cold, causes abundant production of mucus that spreads the infection.
The tests on the vaccine were conducted on eight dromedaries from the Canary Islands, at the Animal Health Research Centre Biocontainment Unit, on the Universitat Autònoma de Barcelona campus. Four of the camels were treated with the vaccine and the other four were used as controls. The animals were studied for almost three months. Those vaccinated received two separate doses and all eight were injected with the MERS virus in between. The camels who did not receive the vaccine were plagued with runny noses, but the camels that got vaccinations were not.
The vaccine that is being tested will not stop the recipient camels from getting infected with the virus; it reportedly is effective in reducing the amount of the virus in the animals that were given the shots, thereby reducing the likelihood of spreading the illness. There are further studies needed to determine if the protection from the vaccine is long-lasting or not. Eventually, the vaccine being tested on the animals could be tested for protecting humans now that the virus has jumped species.
MERS is a relatively new viral disease. The ailment, which is caused by a strain of coronavirus, was first identified in 2012 in Saudi Arabia. The coronavirus family causes a range of respiratory diseases from the common cold to MERS to Severe Acute Respiratory Syndrome (SARS), a variety that created an epidemic in 2003 in Asia, Canada and other areas.
Transmission of MERS between human is not easy, because very direct contact is needed. Most of the cases found in humans have been in the Middle East, hence the name. In the last three years, however, patients with the virus were treated in 26 countries. Saudi Arabia and the Republic of Korea have had the most cases (The initial patient in Korea had visited the Middle East, returned home sick and started the epidemic there when he visited a hospital emergency room after becoming contagious.). Just last month, two more people in Saudi Arabia died from MERS, and the WHO continues to monitor the situation, but the initial tests give hope that a vaccine may stop the spread of the deadly virus in the foreseeable future.
Written and edited by Dyanne Weiss
Universitat Autònoma de Barcelona: New vaccine against Middle East respiratory syndrome virus MERS tested on dromedary camels
World Health Organization: Middle East respiratory syndrome coronavirus (MERS-CoV)
Scientific American: MERS Vaccine Protects Camels, Which Is Good for People
Live Science: 10 Deadly Diseases That Hopped Across Species
Arab News: MERS vaccine ‘a step closer’, say scientists
Photo by Trisha Shears – Creative Commons license.