Beet black scorch virus.
I know you all are thinking what Im thinking. LETS MAKE A VACCINE OUTTA THAT! YAY!!!!
A ton of plant vaccine papers have been rolling out on PubMed since I first wrote about them a few months ago. I couldnt resist writing about another cool paper– How to make a GMO virus that infects plants to make them produce viral proteins for a rotavirus vaccine:
Oral administration of plant-based rotavirus VP6 induces antigen-specific IgAs, IgGs and passive protection in mice
Rotavirus causes diarrhea that kills hundreds of thousands of babies and toddlers every year.
“WAAAAAAAIT, ERV!” some of you readers who call me ERV instead of Abbie might say. “We HAVE a rotavirus vaccine. Actually, we have a couple– Rotarix and Rotateq. Youve written about them before. Why are these people going to all the effort of making another one?”
Rotarix and Rotateq are live attenuated viruses. Even though these vaccines are administered orally, because the viruses are ‘live’, the vaccines have to be kept under refrigeration. The second you mix all the parts together (virus + liquid = oral vaccine), its only ‘good’ for 24 hours.
As we saw with the cholera/E. coli vaccine, not only are plants great as little factories, making tons of vaccine product– once you dry the plant material, it can sit at room temp for at least 3 years and still elicit a protective immune response! The places that need a rotovirus vaccine the most do not have reliable electricity/refrigeration– a plant-based rotavirus vaccine would be a fantastic option for them!
GMO plants are not the only option for us, though. We can transiently infect plant with plant viruses that have been genetically modified to encode for our protein of interest, so the plant will only be a temporary vaccine factory. In the case of this vaccine, scientists wanted plants to make a highly conserved protein, Viral Protein 6 (VP6). Instead of making their plant permanently make VP6 via plant genetic modification, they just altered a plant virus, Beet Black Scorch Virus, to encode VP6. Why Beet Black Scorch Virus? Cause then we can make this vaccine in sugar beet, a popular crop grown all around the world!
Whats SUPER neat about this approach, is that antibodies to VP6 are NOT neutralizing. If you get this vaccine and are exposed to rotavirus, you will probably still get diarrhea. However, antibodies to VP6 interfere with other parts of the viral life-cycle, and still help prime your immune system to ultimately make a neutralizing antibody response– the end result then, is that you still get sick, but its not as bad, and you get better faster.
That is exactly what happened. When they gave the plants-infected-with-a-GMO-scary-sounding-virus-that-makes-VP6 vaccine to mice, the mice made antibodies (IgG and IgA) to VP6. Those mice then breast-fed pups (transferred their anti-VP6 IgA to the babies). When the baby mice were then challenged with real rotavirus, the baby mice still got kinda sick (<40%), but all were totally fine by day 7. Contrast that to the babies fed on moms that did not get the vaccine: 100% got sick, and at day 7, when the other mice were all better, 50% of the control mice were still sick. This could go a long way to stopping lots of infant/toddler deaths.