Antivaxers want green vaccines? How about vaccines produced in plants? Solar powered, green leafy plants– Cant get much more green than that!
The basic idea is that we modify plants to make viral/bacterial proteins, and then we eat the plants, and YAY! Vaccine! How could this possibly work? Doesnt everything just get digested? Well, there are a lot of viruses/bacteria that need your intestines to infect you– Polio, enteric bacteria like salmonella and E. coli and cholera, rotavirus, norovirus, etc. Then you have viruses/bacteria that just want some kind of mucosal site (eyes, mouth, nose) like HIV-1, RSV, CMV, all flavors of herpes, measles, common cold, influenza, Staph, Pseudomonas, Strep, etc.
You have sentinel immune cells embedded in your mucosal tissue, constantly sampling your inner outer surfaces, looking for something that could be causing trouble.
For example, say a dendritic cell in your gut picks up a chunk of an oral polio vaccine you swallowed. It presents this chunk to CD4+ T-cells who are all like “WTF IS THIS SHIT! DO NOT WANT!”, and then it marches up to a lymph node to bitch out other T-cells and B-cells. The B-cells also get real pissed off, and start maturing from IgM/BCR expressing B-cells into mature IgG, IgA, IgE producing B-cells, making antibodies that recognize that chunk of oral polio vaccine. IgA is the antibody you secrete in your saliva (how fast HIV-1 tests work), tears, mucus, intestines, etc. And thats why, if youve had an oral polio vaccine and then you are exposed to ‘wild-type polio’, you dont get infected, much less sick, much less paralyzed.
Here is an image from a Nature Review relating to how this works (I think you can see this– someone tell me if you cant).
So, if we get plants to produce viral/bacterial proteins that cause diseases in us, and we can get immunity to these bugs just by eating a potato or corn or some dried up arabadopsis, that would be pretty damn awesome. Not just because of the immunity, but because vaccines made this way instead of via tissue/egg culture 1) are cheap, 2) have a long shelf-life, 3) are stable in ambient temperatures, 4) insure we are going to get IgA protectivity, 5) dont need any needles (needles in the 3rd world… ehh…)… probably more advantages I havent thought of.
This idea has been around a long time (20 years-ish?), but there has recently been a big push for these kinds of vaccines– as they could be made relatively quickly in response to new outbreaks (ie Swine Flu), or even provide cheap ways to vaccinate against bastards like cholera and malaria. We are even opening plant vaccine factories in Delaware and Texas.
NOMNOMNOM! Green vaccines!