Scientists are trying new, revolutionary techniques to make a SARS-CoV-2 vaccine, but face challenges along the way.
Can Scientists Use RNA to Create a Coronavirus Vaccine?
Published: April 16, 2020
Jennifer Haller: I’m the first person in the United States to receive the experimental coronavirus vaccine.
Neal Browning: I was the second person to enter into COVID-19 trial vaccination.
Haller: I was just looking for something to do to help.
Browning: I said, “If this can bring closure to this pandemic and save lives in the process, I absolutely need to do this.”
Narrator: The coronavirus has unleashed global havoc. A tiny virus with a vicious punch.
How can we hit back?
Akiko Iwasaki: Vaccines will be the savior in this entire pandemic.
Rhiju Das: The idea is to teach our immune systems to take out the coronavirus before the virus takes over our body.
Narrator: There are dozens of efforts underway to make a vaccine against SARS-CoV-2, the virus that causes COVID-19. A handful are using traditional methods, which use killed or weakened versions of all or part of the virus to get our immune system ready to fight. But some are trying a radically new approach.
Das: There’s a new game in town that allows for even faster turnaround in developing and testing and then deploying vaccines. And it’s called an RNA vaccine. RNA, which is a kind of ancient cousin of DNA. RNA molecules are the scripts that viruses use and that our human bodies also use to make proteins.
Narrator: The coronavirus’ RNA codes for at least 24 proteins, including its spike protein, which covers the exterior.
Angela Rasmussen: It’s the protein that makes the coronaviruses have the crown appearance that they’re named after.
Narrator: SARS-CoV-2 uses this protein to bind to and enter our cells, where it then injects its RNA, hijacking those cells to make lots more virus.
Das: It’s almost like a skeleton key for a lock, opening a portal within human cells that the virus can slip in.
Iwasaki: So if we can block that process, if you can neutralize the virus before even it enters the cell, that will be probably the Achilles heel that we need to target.
Das: We can tell our body, “Hey, if you see anything with that kind of skeleton key shape, then just destroy it.”
Narrator: This is where an RNA vaccine comes in, which becomes possible when you have a genetic sequence of the virus, and you know which genes code for which proteins.
Das: So the concept of an RNA vaccine is: Let’s inject the RNA molecule that encodes for the spike protein.
Rasmussen: It’s making your cell effectively do the work of creating this viral protein that is going to be recognized by your immune system and trigger the development of these antibodies.
Das: Our bodies won’t make a full-fledged infectious virus. They’ll just make a little piece and then learn to recognize it and then get ready to destroy the virus if it then later comes and invades us.
Iwasaki: The advantage of the RNA vaccine is that it can be produced within a matter of days. So these types of vaccines are much faster to generate.
Das: Much faster than it takes, for example, to even prepare a flu shot for this seasonal flu strain. But on the other hand, it’s a relatively new, unproven technology. And there’s still no example of an RNA vaccine that’s been deployed worldwide in the way that we need for the coronavirus.
Rasmussen: There is the possibility for unforeseen, adverse effects.
Iwasaki: So this is all new territory. Whether it would elicit protective, robust immune response against this virus is just unknown right now.
Narrator: In addition, RNA molecules have a weakness.
Das: Here’s the dirty secret. They are ephemeral. They’re like the Snapchat of molecules. Like literally our bodies make an RNA script and destroy it a few minutes later once they use it as a little temporary instruction manual to make proteins.
And so here’s the issue: If we make a bunch of these RNA vaccines and keep them in the fridge, if you wait a couple of days, they’re no longer good vaccines. Their expiration date is like a couple of days after you make them. And they have to be kept at a temperature of -80°C, which is super cold.
This is a big deal breaker. We’ll have to find a way to stabilize the RNA so they’re refrigerator safe. And no one has quite figured out how to do that. And that is actually the problem that I’m involved in.
Narrator: Das is optimistic.
Das: I think we’re going to have a vaccine.
Narrator: But it’s too soon to tell which approach will get us the vaccine we need. Traditional techniques may yet win the race.
Iwasaki: Right now, I wouldn’t rule anything out because we just need a really good vaccine against this virus. I think the best approach is a multi-pronged approach where multiple vaccines are tried for efficacy and safety.
Rasmussen: And I’m hopeful that there will be a lot of public support and really public will to continue working on some of these things so that we’re more protected and more prepared for the next pathogen that might emerge.
Narrator: And in the midst of the current pandemic, it takes all kinds of people pitching in to get us to the other side.
Haller: The piece that I played here really does pale in comparison to the sacrifices that others are making right now.
Browning: It’s not heroic to sit down and get an injection in your arm. What’s heroic are the people who are on the front lines exposing themselves to try and save lives every day. That’s what heroism is.
Produced and Narrated by: Ari Daniel
Research and Production: Caitlin Saks and Madeline Weir
Additional Footage and Visuals:
Vital Mind Media
Protein Structures: Zhang C, Zheng W, Huang X, Bell EW, Zhou X, Zhang Y (2020) J Proteome Res. 19: 1351-1360
RNA Sequence: Wu F, Zhao S, Yu B, et al. (2020) Nature. 579(7798): 265-269
Iwiploppenisse / CC BY 3.0
tommccann / CC0 1.0
© 2020 WGBH Educational Foundation