Scientists Are Growing an Edible Cholera Vaccine in Rice
The world's attention has been focused on the coronavirus crisis but Yemen, Bangladesh and many others countries in Asia and Africa are also in the grips of another pandemic: cholera. The current cholera pandemic first emerged in the 1970s and has devastated many communities in low-income countries. Each year, cholera is responsible for an estimated 1.3 million to 4 million cases and 21,000 to 143,000 deaths worldwide.
Immunologist Hiroshi Kiyono and his team at the University of Tokyo hope they can be part of the solution: They're making a cholera vaccine out of rice.
"It is much less expensive than a traditional vaccine, by a long shot."
Cholera is caused by eating food or drinking water that's contaminated by the feces of a person infected with the cholera bacteria, Vibrio cholerae. The bacteria produces the cholera toxin in the intestines, leading to vomiting, diarrhea and severe dehydration. Cholera can kill within hours of infection if it if's not treated quickly.
Current cholera vaccines are mainly oral. The most common oral are given in two doses and are made out of animal or insect cells that are infected with killed or weakened cholera bacteria. Dukoral also includes cells infected with CTB, a non-harmful part of the cholera toxin. Scientists grow cells containing the cholera bacteria and the CTB in bioreactors, large tanks in which conditions can be carefully controlled.
These cholera vaccines offer moderate protection but it wears off relatively quickly. Cold storage can also be an issue. The most common oral vaccines can be stored at room temperature but only for 14 days.
"Current vaccines confer around 60% efficacy over five years post-vaccination," says Lucy Breakwell, who leads the U.S. Centers for Disease Control and Prevention's cholera work within Global Immunization Division. Given the limited protection, refrigeration issue, and the fact that current oral vaccines require two disease, delivery of cholera vaccines in a campaign or emergency setting can be challenging. "There is a need to develop and test new vaccines to improve public health response to cholera outbreaks."
A New Kind of Vaccine
Kiyono and scientists at Tokyo University are creating a new, plant-based cholera vaccine dubbed MucoRice-CTB. The researchers genetically modify rice so that it contains CTB, a non-harmful part of the cholera toxin. The rice is crushed into a powder, mixed with saline solution and then drunk. The digestive tract is lined with mucosal membranes which contain the mucosal immune system. The mucosal immune system gets trained to recognize the cholera toxin as the rice passes through the intestines.
The cholera toxin has two main parts: the A subunit, which is harmful, and the B subunit, also known as CTB, which is nontoxic but allows the cholera bacteria to attach to gut cells. By inducing CTB-specific antibodies, "we might be able to block the binding of the vaccine toxin to gut cells, leading to the prevention of the toxin causing diarrhea," Kiyono says.
Kiyono studies the immune responses that occur at mucosal membranes across the body. He chose to focus on cholera because he wanted to replicate the way traditional vaccines work to get mucosal membranes in the digestive tract to produce an immune response. The difference is that his team is creating a food-based vaccine to induce this immune response. They are also solely focusing on getting the vaccine to induce antibodies for the cholera toxin. Since the cholera toxin is responsible for bacteria sticking to gut cells, the hope is that they can stop this process by producing antibodies for the cholera toxin. Current cholera vaccines target the cholera bacteria or both the bacteria and the toxin.
David Pascual, an expert in infectious diseases and immunology at the University of Florida, thinks that the MucoRice vaccine has huge promise. "I truly believe that the development of a food-based vaccine can be effective. CTB has a natural affinity for sampling cells in the gut to adhere, be processed, and then stimulate our immune system, he says. "In addition to vaccinating the gut, MucoRice has the potential to touch other mucosal surfaces in the mouth, which can help generate an immune response locally in the mouth and distally in the gut."
Cost Effectiveness
Kiyono says the MucoRice vaccine is much cheaper to produce than a traditional vaccine. Current vaccines need expensive bioreactors to grow cell cultures under very controlled, sterile conditions. This makes them expensive to manufacture, as different types of cell cultures need to be grown in separate buildings to avoid any chance of contamination. MucoRice doesn't require such an expensive manufacturing process because the rice plants themselves act as bioreactors.
The MucoRice vaccine also doesn't require the high cost of cold storage. It can be stored at room temperature for up to three years unlike traditional vaccines. "Plant-based vaccine development platforms present an exciting tool to reduce vaccine manufacturing costs, expand vaccine shelf life, and remove refrigeration requirements, all of which are factors that can limit vaccine supply and accessibility," Breakwell says.
Kathleen Hefferon, a microbiologist at Cornell University agrees. "It is much less expensive than a traditional vaccine, by a long shot," she says. "The fact that it is made in rice means the vaccine can be stored for long periods on the shelf, without losing its activity."
A plant-based vaccine may even be able to address vaccine hesitancy, which has become a growing problem in recent years. Hefferon suggests that "using well-known food plants may serve to reduce the anxiety of some vaccine hesitant people."
Challenges of Plant Vaccines
Despite their advantages, no plant-based vaccines have been commercialized for human use. There are a number of reasons for this, ranging from the potential for too much variation in plants to the lack of facilities large enough to grow crops that comply with good manufacturing practices. Several plant vaccines for diseases like HIV and COVID-19 are in development, but they're still in early stages.
In developing the MucoRice vaccine, scientists at the University of Tokyo have tried to overcome some of the problems with plant vaccines. They've created a closed facility where they can grow rice plants directly in nutrient-rich water rather than soil. This ensures they can grow crops all year round in a space that satisfies regulations. There's also less chance for variation since the environment is tightly controlled.
Clinical Trials and Beyond
After successfully growing rice plants containing the vaccine, the team carried out their first clinical trial. It was completed early this year. Thirty participants received a placebo and 30 received the vaccine. They were all Japanese men between the ages of 20 and 40 years old. 60 percent produced antibodies against the cholera toxin with no side effects. It was a promising result. However, there are still some issues Kiyono's team need to address.
The vaccine may not provide enough protection on its own. The antigen in any vaccine is the substance it contains to induce an immune response. For the MucoRice vaccine, the antigen is not the cholera bacteria itself but the cholera toxin the bacteria produces.
"The development of the antigen in rice is innovative," says David Sack, a professor at John Hopkins University and expert in cholera vaccine development. "But antibodies against only the toxin have not been very protective. The major protective antigen is thought to be the LPS." LPS, or lipopolysaccharide, is a component of the outer wall of the cholera bacteria that plays an important role in eliciting an immune response.
The Japanese team is considering getting the rice to also express the O antigen, a core part of the LPS. Further investigation and clinical trials will look into improving the vaccine's efficacy.
Beyond cholera, Kiyono hopes that the vaccine platform could one day be used to make cost-effective vaccines for other pathogens, such as norovirus or coronavirus.
"We believe the MucoRice system may become a new generation of vaccine production, storage, and delivery system."
The Friday Five: Artificial DNA Could Give Cancer the Hook
In this week's Friday Five, artificial DNA could give cancer the hook. Plus, research suggests that this daily practice can improve relationships, social media could be good for finding factual information, injecting a gel may speed up recovery from injuries, and a blood pressure medicine is promising for a long healthy life.
The Friday Five covers five stories in research that you may have missed this week. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
Here are the promising studies covered in this week's Friday Five:
- Artificial DNA gives cancer the hook
- This daily practice could improve relationships
- Can social media handle the truth?
- Injecting a gel could speed up recovery
- A blood pressure medicine for a long healthy life
9 Tips for Online Mental Health Therapy
Research shows that, for most patients, online therapy offers the same benefits as in-person therapy, yet many people still resist it. A behavioral scientist explains how you can use it to improve mental health.
Telehealth offers a vast improvement in access and convenience to all sorts of medical services, and online therapy for mental health is one of the most promising case studies for telehealth. With many online therapy options available, you can choose whatever works best for you. Yet many people are hesitant about using online therapy. Even if they do give it a try, they often don’t know how to make the most effective use of this treatment modality.
Why do so many feel uncertain about online therapy? A major reason stems from its novelty. Humans are creatures of habit, prone to falling for what behavioral scientists like myself call the status quo bias, a predisposition to stick to traditional practices and behaviors. Many people reject innovative solutions even when they would be helpful. Thus, while teletherapy was available long before the pandemic, and might have fit the needs of many potential clients, relatively few took advantage of this option.
Even when we do try new methodologies, we often don’t do so effectively, because we cling to the same approaches that worked in previous situations. Scientists call this behavior functional fixedness. It’s kind of like the saying about the hammer-nail syndrome: “when you have a hammer, everything looks like a nail.”
These two mental blindspots, the status quo bias and functional fixedness, impact decision making in many areas of life. Fortunately, recent research has shown effective and pragmatic strategies to defeat these dangerous errors in judgment. The nine tips below will help you make the best decisions to get effective online therapy, based on the latest research.
Trust the science of online therapy
Extensive research shows that, for most patients, online therapy offers the same benefits as in-person therapy.
For instance, a 2014 study in the Journal of Affective Disorders reported that online treatment proved just as effective as face-to-face treatment for depression. A 2018 study, published in Journal of Psychological Disorders, found that online cognitive behavioral therapy, or CBT, was just as effective as face-to-face treatment for major depression, panic disorder, social anxiety disorder, and generalized anxiety disorder. And a 2014 study in Behaviour Research and Therapy discovered that online CBT proved effective in treating anxiety disorders, and helped lower costs of treatment.
During the forced teletherapy of COVID, therapists worried that those with serious mental health conditions would be less likely to convert to teletherapy. Yet research published in Counselling Psychology Quarterly has helped to alleviate that concern. It found that those with schizophrenia, bipolar disorder, severe depression, PTSD, and even suicidality converted to teletherapy at about the same rate as those with less severe mental health challenges.
Yet teletherapy may not be for everyone. For example, adolescents had the most varied response to teletherapy, according to a 2020 study in Family Process. Some adapted quickly and easily, while others found it awkward and anxiety-inducing. On the whole, children with trauma respond worse to online therapy, per a 2020 study in Child Abuse & Neglect. The treatment of mental health issues can sometimes require in-person interactions, such as the use of eye movement desensitization and reprocessing to treat post-traumatic stress disorder. And according to a 2020 study from the Journal of Humanistic Psychology, online therapy may not be as effective for those suffering from loneliness.
Leverage the strengths of online therapy
Online therapy is much more accessible than in-person therapy for those with a decent internet connection, webcam, mic, and digital skills. You don’t have to commute to your therapist’s office, wasting money and time. You can take much less medical leave from work, saving you money and hassle with your boss. If you live in a sparsely populated area, online therapy could allow you to access many specialized kinds of therapy that isn’t accessible locally.
Online options are much quicker compared to the long waiting lines for in-person therapy. You also have much more convenient scheduling options. And you won’t have to worry about running into someone you know in the waiting room. Online therapy is easier to conceal from others and reduces stigma. Many patients may feel more comfortable and open to sharing in the privacy and comfort of their own home.
You can use a variety of communication tools suited to your needs at any given time. Video can be used to start a relationship with a therapist and have more intense and nuanced discussions, but can be draining, especially for those with social anxiety. Voice-only may work well for less intense discussions. Email offers a useful option for long-form, well-thought-out messages. Texting is useful for quick, real-time questions, answers, and reinforcement.
Plus, online therapy is often cheaper than in-person therapy. In the midst of COVID, many insurance providers have decided to cover online therapy.
Address the weaknesses
One weakness is the requirement for appropriate technology and skills to engage in online therapy. Another is the difficulty of forming a close therapeutic relationship with your therapist. You won’t be able to communicate non-verbals as fully and the therapist will not be able to read you as well, requiring you to be more deliberate in how you express yourself.
Another important issue is that online therapy is subject to less government oversight compared to the in-person approach, which is regulated in each state, providing a baseline of quality control. As a result, you have to do more research on the providers that offer online therapy to make sure they’re reputable, use only licensed therapists, and have a clear and transparent pay structure.
Be intentional about advocating for yourself
Figure out what kind of goals you want to achieve. Consider how, within the context of your goals, you can leverage the benefits of online therapy while addressing the weaknesses. Write down and commit to achieving your goals. Remember, you need to be your own advocate, especially in the less regulated space of online therapy, so focus on being proactive in achieving your goals.
Develop your Hero’s Journey
Because online therapy can occur at various times of day through videos calls, emails and text, it might feel more open-ended and less organized, which can have advantages and disadvantages. One way you can give it more structure is to ground these interactions in the story of your self-improvement. Our minds perceive the world through narratives. Create a story of how you’ll get from where you are to where you want to go, meaning your goals.
A good template to use is the Hero’s Journey. Start the narrative with where you are, and what caused you to seek therapy. Write about the obstacles you will need to overcome, and the kind of help from a therapist that you’ll need in the process. Then, describe the final end state: how will you be better off after this journey, including what you will have learned.
Especially in online therapy, you need to be on top of things. Too many people let the therapist manage the treatment plan. As you pursue your hero’s journey, another way to organize for success is to take notes on your progress, and reevaluate how you’re doing every month with your therapist.
Identify your ideal mentor
Since it’s more difficult to be confident about the quality of service providers in an online setting, you should identify in advance the traits of your desired therapist. Every Hero’s Journey involves a mentor figure who guides the protagonist through this journey. So who’s your ideal mentor? Write out their top 10 characteristics, from most to least important.
For example, you might want someone who is:
- Empathetic
- Caring
- Good listener
- Logical
- Direct
- Questioning
- Non-judgmental
- Organized
- Curious
- Flexible
That’s my list. Depending on what challenge you’re facing and your personality and preferences, you should make your own. Then, when you are matched with a therapist, evaluate how well they fit your ideal list.
Fail fast
When you first match with a therapist, try to fail fast. That means, instead of focusing on getting treatment, focus on figuring out if the therapist is a good match based on the traits you identified above. That will enable you to move on quickly if they’re not, and it’s very much worth it to figure that out early.
Tell them your goals, your story, and your vision of your ideal mentor. Ask them whether they think they are a match, and what kind of a treatment plan they would suggest based on the information you provided. And observe them yourself in your initial interactions, focusing on whether they’re a good match. Often, you’ll find that your initial vision of your ideal mentor is incomplete, and you’ll learn through doing therapy what kind of a therapist is the best fit for you.
Choose a small but meaningful subgoal to work on first
This small subgoal should be sufficient to be meaningful and impactful for improving your mental health, but not a big stretch for you to achieve. This subgoal should be a tool for you to use to evaluate whether the therapist is indeed a good fit for you. It will also help you evaluate whether the treatment plan makes sense, or whether it needs to be revised.
Know when to wrap things up
As you approach the end of your planned work and you see you’re reaching your goals, talk to the therapist about how to wrap up rather than letting things drag on for too long. You don’t want to become dependent on therapy: it’s meant to be a temporary intervention. Some less scrupulous therapists will insist that therapy should never end and we should all stay in therapy forever, and you want to avoid falling for this line. When you reach your goals, end your therapy, unless you discover a serious new reason to continue it. Still, it may be wise to set up occasional check-ins once every three to six months to make sure you’re staying on the right track.