Mareeg.com-Chinese researchers said Thursday they may have found a simple, convenient andpotentially “revolutionary” new approach to create effective vaccines by just geneticallytweaking live viruses to make them capable of activating the immune system but unable toreplicate in healthy cells.
In a proof-of-principle study, the vaccine they developed against flu proved effective inmice, guinea pigs and ferrets, the researchers reported in the U.S. journal Science.
“We believe our approach will become a general, simple and convenient approach forgeneration of live virus vaccines adapted to almost any viruses,” Professor Deming Zhou ofPeking University, who led the study, told Xinhua.
“This will help control pandemics of influenza and other life-threatening RNA viruses.”
A major challenge for converting infectious viruses, such as those responsible forinfluenza, Ebola, Zika and AIDS pandemics, into live vaccines is to render them asavirulent as possible while maintaining their high infectivity to elicit sufficient immunity,Zhou said, noting achieving such a feat would “represent a revolution in vaccinology.”
Traditionally, vaccines use either dead or weakened forms of viruses. Those containingweakened viruses retain some degree of ability to replicate and therefore still have toxiceffects, he said.
In their study, Zhou and colleagues modified a three-consecutive-base-segment in thegenome of influenza A virus, known as premature termination codon (PTC), and foundtheir modified virus — though still just as potent in terms of activating the immune system– cannot replicate in regular cells.
The new vaccine was found to offer an antibody response comparable to an existing live-virus vaccine, and a second dose further increased the amounts of antibodies by a factor ofsix to eight.
Similar beneficial effects were seen when the viral vaccine was tested against severaldifferent strains of influenza, and tested in guinea pigs and ferrets.
“Vaccination with such live PTC viruses in animal model via the intranasal route elicitedall aspects of immune responses including humoral, mucosal and T cell-mediatedimmunity against hyper-variable and even antigenically distinct influenza virus strains,”said Zhou.
“Furthermore, multiple PTCs-harboring viruses are not only prophylactic but alsotherapeutic to existing infecting viruses,” he noted.
Zhou said his team will continue the research on their whole new flu vaccine and test it inclinical trials as early as possible.
Source: People’s Daily