Jonas Salk created a vaccine against polio that has been used since 1955; Albert Sabin created another version that has been on the market since 1961. Together, these two vaccines have nearly eliminated polio from the face of the earth.
Emphasis on nearly. Outbreaks have persisted in developing nations in Asia, Africa and the Americas, in part due to limitations of these vaccines. Most recently, in 2013, Israel reported a “silent” outbreak of polio, in which no one got sick but the virus was found in the environment and in vaccinated individuals.
New research led by University of Pennsylvania scientists offers hope for an alternative. Collaborating with researchers from the U.S. Centers for Disease Control and Prevention and the U.S. Food and Drug Administration, the Penn team developed an oral vaccine booster by manipulating plants to express a protein found in the polio virus. Tests with sera from immunized mice show that the booster confers immunity against all three serotypes of polio.
“Our vaccine research has the potential to provide a timely solution to deal with polio outbreaks around the globe,” said Henry Daniell, professor in the Department of Biochemistry in Penn’s School of Dental Medicine and senior author on the work.
Using tracer viruses, researchers found that contamination of just a single doorknob or table top results in the spread of viruses throughout office buildings, hotels, and health care facilities.
Within 2 to 4 hours, the virus could be detected on 40 to 60 percent of workers and visitors in the facilities and commonly touched objects, according to research presented at the 54th Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC), an infectious disease meeting of the American Society for Microbiology.
There is a simple solution, though, says Charles Gerba of the University of Arizona, Tucson, who presented the study.
“Using disinfecting wipes containing quaternary ammonium compounds (QUATS) registered by EPA as effective against viruses like norovirus and flu, along with hand hygiene, reduced virus spread by 80 to 99 percent,” he says.
Norovirus is the most common cause of acute gastroenteritis in the United States, according to the Centers for Disease Control and Prevention (CDC). Each year, it causes an estimated 19-21 million illnesses and contributes to 56,000-71,000 hospitalizations and 570-800 deaths. Touching surfaces or objects contaminated with norovirus then putting your fingers in your mouth is a common source of infection.
In the study, Gerba and his colleagues used bacteriophage MS-2 as a surrogate for the human norovirus, as it is similar in shape, size and resistance to disinfectants. The phage was placed on 1 to 2 commonly touched surfaces (door knob or table top) at the beginning of the day in office buildings, conference room and a health care facility. After various periods of time (2 to 8 hours) they sampled 60 to 100 fomites, surfaces capable of carrying infectious organisms (light switches, bed rails, table tops, countertops, push buttons, coffee pots handles, sink tap handles, door knobs, phones and computer equipment), for the phages.
“Within 2 to 4 hours between 40 to 60% of the fomites sampled were contaminated with virus,” says Gerba.