explain xkcd - User contributions [en]

2425: mRNA Vaccine

2021-02-17T04:54:21Z

172.69.63.237: /* Explanation */ SARS-CoV-2 is the name of the COVID-19 virus

{{comic
| number = 2425
| date = February 15, 2021
| before = [[#Explanation|↓ Skip to explanation ↓]]
| title = mRNA Vaccine
| image = mrna_vaccine.png
| titletext = To ensure lasting immunity, doctors recommend destroying a second Death Star some time after the first.
}}

==Explanation==
{{incomplete|Created by a THERMAL EXHAUST PORT. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

This comic is another in a [[:Category:COVID-19|series of comics]] related to the {{w|2019–20 coronavirus outbreak|2020 pandemic}} of the {{w|coronavirus}} {{w|SARS-CoV-2}}, which causes {{w|COVID-19}}. This one is another analogy to how {{w|mRNA vaccines}} work, by creating inactive fragments of the virus to prime the immune system to be prepared to stave off the real thing. This is done in response to Cueball's question to the person vaccinating him, "Why would my body attack something it made itself?", using elements of the film ''{{w|Star Wars (film)|Star Wars: Episode IV}}'' as an analogy.

The analogy starts in the second panel, where the Rebel Alliance has retrieved the {{w|Death Star}} plans, conveyed by {{w|Princess Leia}} to General [https://starwars.fandom.com/wiki/Jan_Dodonna Jan Dodonna] (in ''Star Wars'', via {{w|R2-D2}} and some adventures, but shown as a simple handoff here). The Death Star is a space station the size of a small moon that has the power to destroy planets. However, in this panel, the "Death Star plans" are passed down a line of people until they get reinterpreted as something to build and are used to build a Death Star, in contrast to the film, where the plans are used to find a weakness in the enemy Death Star and destroy it. The ensuing panels indicate that people are sent to build the Death Star according to the plans that Princess Leia provided. In the analogy, the mRNA in the vaccine corresponds to the plans for the Death Star, the spike proteins (inactive COVID-19 virus fragments) that the mRNA code for correspond to the benign Death Star itself, and the cellular processes that build spike proteins correspond to the builders of the benign Death Star. Just as merely having the plans on hand led to the Death Star being built, the mere presence of the mRNA in the cellular environment leads to it being translated, producing the viral protein.

After Leia's Death Star has been built, it is positioned near a planet/moon. This Death Star is ''benign'': it only ''looks'' dangerous and isn't about to actually hurt anyone, as Leia had it built essentially for target practice. This is evidenced by the pilot of the Death Star stating that they don't have the laser wired up. The Rebels mobilize to destroy this benign Death Star because it looks like an enemy battle station. However, the Death Star operators are confused, because Leia (a member of the Rebels) had ordered its construction. The Rebels initially attack the surface of the benign Death Star, without much effect; Leia orders the factories to continue developing torpedoes and ships as they run out, presumably putting an extra workload on the factory workers and tiring them out. In the analogy, the Rebels correspond to the immune system's {{w|B cells}} and {{w|T cells}}, which mobilize to attack the spike proteins (the benign Death Star) made as a result of the vaccine, but are often ineffective at first. The body keeps producing these immune cells, trying many variants (many ways of attacking the benign Death Star) in an attempt to find one that works well against the spike proteins. This results in Cueball experiencing {{w|side effects}} from the vaccine, including soreness and tiredness, and he lies down and rests.

After much effort on the Rebels' part, they find a weakness in the benign Death Star, a "thermal exhaust port" vulnerable to "proton torpedoes" that can destroy the Death Star. Firing a proton torpedo down the exhaust port destroys a Death Star very rapidly, compared to the initial, ineffective frontal assault on the surface. After this benign Death Star is destroyed, Princess Leia allows the fleet to stand down. In the analogy, the immune system (the Rebel Alliance) figures out a way to attach to the spike proteins (attack the benign Death Star) made by the mRNA vaccine; the immune system's {{w|antibodies}} (Rebel planners) now "know" how to recognize and destroy things that have these spike proteins — including SARS-CoV-2 virus particles (real, dangerous Death Stars).

Later on, the vaccinated Cueball approaches White Hat, who is maskless, coughing, and presumably sick with COVID-19. It is also possible he has some other respiratory disorder which prevents him from being able to safely wear a mask. Metaphorically, the rebels are attacked by a truly threatening Death Star, this time led by the enemy, {{w|Darth Vader}}, who says a quote from ''Star Wars'' (although this quote is actually spoken by the Emperor in ''{{w|Return of the Jedi}}''). By now, though, the Rebel Fleet led by Leia already knows the weakness of a Death Star, the thermal exhaust port, and quickly destroys Vader's Death Star. In the analogy, Cueball's immune system (the Rebel Alliance) is able to destroy dangerous SARS-CoV-2 virus particles (real, threatening Death Stars) because it knows about the virus's spike proteins (the thermal exhaust port). This is represented by Cueball not experiencing any suffering from COVID-19 (Vader's Death Star getting blown up immediately), and he goes on his way whistling merrily, perhaps to the tune of [https://www.youtube.com/watch?v=yixG8pfncOs The Throne Room/End Title] (from the ceremony celebrating the destruction of the Death Star).

Cueball's wearing of a mask is in accordance with {{w|Centers for Disease Control and Prevention|CDC}} guidelines, which recommend continuing to wear a mask, practicing social distancing, etc. after getting the vaccine; doctors at CDC "don’t yet know whether getting a COVID-19 vaccine will prevent you from spreading the virus that causes COVID-19 to other people, even if you don’t get sick yourself."[https://www.cdc.gov/coronavirus/2019-ncov/vaccines/faq.html] None of the vaccines available as of when the comic was posted are 100% effective at preventing infection, with the best ones about 94% effective, but all vaccines that are approved or submitted for approval are completely (100.00%) effective at preventing death from COVID-19.

The title text references the fact that the two COVID-19 vaccines authorized for use in the United States as of the date of publication (the {{w|Pfizer–BioNTech COVID-19 vaccine|Pfizer-BioNTech one}} and the {{w|Moderna COVID-19 vaccine|Moderna one}}) require [[2422: Vaccine Ordering|two doses of vaccine]] to be fully effective, as do many others in use worldwide (AstraZeneca, Gameleya Institute, Sinovac, etc.). The second dose strengthens the body's immune response to the spike proteins and causes it to "remember", via antibodies, how to attack those proteins for a long time — hopefully years or even decades. Likewise, the Rebels in the movies destroy two Death Stars, the second one in ''Return of the Jedi''. Incidentally, that second Death Star was destroyed while it was apparently incomplete, much like the Death Star here was destroyed before it could destroy Cueball; however, in the film, the Emperor had deliberately left it with an incomplete outer structure to lure the Rebellion into attacking it, only for the Rebels to find that its superlaser was fully operational.

Vaccination was also explained, xkcd-style, in [[2406: Viral Vector Immunity]]. References to the ''{{w|Star Wars}}'' franchise are a [[:Category:Star Wars|recurring theme]] on xkcd.

==Transcript==
:[Cueball seated in a doctor's office getting a dose of a COVID-19 vaccine. Both he and the doctor are wearing masks; the doctor is also wearing a scrub cap.]
:Doctor: The vaccine contains mRNA instructions for making the virus spike protein.
:Cueball: Weird, so the vaccine is just blueprints?
:Doctor: Yup! Your body reads the mRNA, makes the proteins, and then has an immune reaction to them.
:Cueball: Why would my body attack something it made itself?
:Doctor: Well...

:[Princess Leia and General Dodonna in frame.]
:Leia: Here are the Death Star plans.
:Dodonna: Thank you, Princess.

:[Dodonna, Ponytail, and White Hat in frame.]
:Dodonna: These blueprints are from Princess Leia.
:Ponytail: Ugh, she's always giving us projects.

:[Ponytail and Cueball in frame.]
:Ponytail: Here, take these blueprints to your construction crew.
:Cueball: Affirmative. What is it?
:Ponytail: No idea. Something the Princess wants.
:Cueball: Copy that.

:Panel heading: Soon...
:[A view from outside of the Death Star.]
:Voice from Death Star: Hi, Commander? Construction crew B here.

:[A view from inside the Death Star, with a planet visible through two adjacent windows. Cueball is standing at some kind of control/communications panel.]
:Cueball: We finished building the Princess's big metal orb thing.

:[A view from outside the Death Star again, with the curve of the planet in the foreground.]
:Voice from Death Star: Do you know if she wants us to park it somewhere, or—
:Voices from the planet: '''''AAAAAA!!!'''''

:[A view from the planet's surface with the Death Star in the sky. 3 Cueballs, a Megan-like character, and Ponytail are on the planet's surface.]
:Voice from Death Star: ...Is everything ok?
:Cueball 1: '''''AAAAAAA!'''''
:Cueball 2: ''Imperial battle station!!!''
:Ponytail & Cueball 3: ''AAAAAAAAAA''
:Offscreen voice: ''Red Alert Red Alert''

:[Another view from the planet's surface. There is some type of military encampment surrounded by an open field, with trees and mountains in the background. People are running around on the field, which also contains several currently grounded craft and several flying craft streaming toward the Death Star.]
:Death Star voice: Hello?
:Generic field voices: ''Get the fighters in the air!''
:''Red Alert''
:''Blow it up! Blow it up!''
:''AAAAA''
:Generic tree voices: '''''AAAAAaa'''''
:Generic spacecraft voices: ''Kill it kill it kill it kill it kill it kill it''

:[A zoomed-in view of the outside of the Death Star, which is accumulating light damage. Numerous spacecraft are shooting at it; various explosions occur on the Death Star's surface and in space nearby.]
:Death Star voice: Hello?
:Generic spacecraft voices: ''Shoot it! Shoot it! Shoot it!''
:That armor's too strong! We're not getting through!
:''Keep firing!''

:[A view from inside the Death Star again with Cueball at the control panel and the planet in the background windows; various projectiles and explosions can be seen through the window.]
:Cueball: Can everybody please just chill? We don't even have the laser thing wired up. We—
:'''''BOOM'''''
:''Hey!!'' I ''said'', we...

:[Ponytail enters from the left, and points to her left. Princess Leia points at her.]
:Ponytail: We can't get through! We're running out of proton torpedoes!
:Leia: Send every crew to build more torpedoes!
:Ponytail: There aren't enough ships to—
:Leia: ''Build more ships!!''

:[Ponytail is standing still and Princess Leia is walking to the right with her fists raised.]
:Ponytail: That thing is just sitting there. Are you sure we—
:Leia: ''Keep building ships! Build ships forever! '''Destroy the orb!'''''

:[A view of the Death Star in space and the curvature of the planet off to the side. An enormous torrent of (barely visible) ships is seen streaming from the planet's surface to the Death Star. The damage to the Death Star is slightly worse.]
:Generic ship voices: '''''aaaaAAAAAAAAaaaaa'''''
:Death Star voice: What is ''wrong'' with you people?

:[Back in the real world, Cueball is standing with arms hunched and a cartoon helix above his head. Megan stands next to him.]
:Cueball: Definitely feeling a little sore.
:Megan: Yeah, they said you might have some side effects.
:Megan: You lie down—I'll get you some hot tea and a blanket.

:[An outside view of the damaged Death Star with ships swarming it.]
:Generic voices: ''Die die die die! Die!''

:[An inside view; Cueball appears injured, and the control panel is damaged with a fire on the ground nearby.]
:Cueball: I hate you all so much.

:[The outside of the Death Star again.]
:Ship 1: What's that?!
:Ship 2: Looks like a thermal exhaust port.
:Ship 3: I'm going in!

:[The outside of the Death Star.]
:''pew pew pew pew pew pew''

:[Beat panel.]

:[The Death Star explodes.]

:[A disheveled Dodonna, Princess Leia, and Ponytail in frame.]

:[The same frame.]
:Leia: Good work.

:[In the real world, Cueball sits on top of a bed with a blanket draped over his lap. Megan stands next to the bed.]
:Cueball: I'm feeling better today.
:Megan: That's great!

:Panel heading: A few months later...
:[Cueball and White Hat walking past each other. Cueball is wearing a face mask; White Hat isn't but coughs into his elbow.]
:White Hat: ''Cough cough''

:[The real Death Star drifts toward the planet.]
:Death Star voice: We have reached the rebel system, Lord Vader.

:[View from inside the real Death Star.]
:Vader: Now they shall witness the firepower of this fully armed and oper—

:[Leia, Ponytail, and Cueball in frame.]
:Leia: '''''Thermal exhaust port!!'''''
:Ponytail: ''Aaa''
:Cueball: ''Aaa''

:[An equally large torrent of ships stream from the planet to the real Death Star.]
:Death Star voice: What.
:Various ships: '''''aA AAAAAAA aaa aAAAAAAA aaa'''''
:'''''AAAAAA aaa aAAAAA'''''

:[The Death Star explodes, leaving debris trailing away.]

:[In the real world, White Hat and Cueball continue to walk past each other.]
:Cueball: ♫ ♫

{{comic discussion}}

[[Category:Comics featuring face masks]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring White Hat]]
[[Category:Multiple Cueballs]]
[[Category:COVID-19]]
[[Category:Star Wars]]
[[Category:Biology]]

Talk:2343: Mathematical Symbol Fight

2020-08-10T18:20:15Z

172.69.63.237: Thoughts on partial derivative and Delta vs A

Can I get aleph-null aleph-shaped throwing stars? [[User:LunarNapolean|LunarNapolean]] ([[User talk:LunarNapolean|talk]]) 20:18, 7 August 2020 (UTC)
: I'd prefer octothorpe throwing stars. [[Special:Contributions/108.162.219.168|108.162.219.168]] 16:19, 10 August 2020 (UTC)
Apologies to whoever added the "citation needed" that I stepped on. -- brad

That zeta looks conspicuously bad. I wonder if this comic will get a cleaned-up version uploaded. [[Special:Contributions/108.162.237.16|108.162.237.16]] 20:51, 7 August 2020 (UTC)

[[Megan]] usually has shoulder-length hair, so the person being attacked by Ponytail is probably not Megan... except in so far as all brunettes in this comic are called 'Megan'. [[User:LtPowers|LtPowers]] ([[User talk:LtPowers|talk]]) 20:53, 7 August 2020 (UTC)
:Is one of them [[Danish]]? And one of them Megan? [[Special:Contributions/172.69.33.121|172.69.33.121]] 22:49, 7 August 2020 (UTC)

I think Randall is underestimating the weapon utility of psi. There's a real-world martial arts [https://en.wikipedia.org/wiki/Sai_(weapon) weapon] that looks somewhat like it.[[Special:Contributions/172.69.68.197|172.69.68.197]] 22:04, 7 August 2020 (UTC)
:I think he’s also seriously underestimating the value of keeping your fingers attached to your hand. Swords have guards for a reason. I’d pick the contour integral over anything else there.

Considering the title text, a bass clef looks pretty formidable, close to a bat'leth. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 00:31, 8 August 2020 (UTC)
:Yes, but the treble clef is the one in the title text, and that’s nothing like a Klingon {{w|bat'leth}}. I removed the comment from the table. [[User:Adam1729|Adam1729]] ([[User talk:Adam1729|talk]]) 02:09, 8 August 2020 (UTC)
::If we're talking clefs/klingon weaponry, get on the viola clef. That's bat'leth AF. It's even known as a "K Clef" in some circles. You could do some pretty hefty damage with a viola clef.
::Or a viola...[[Special:Contributions/141.101.98.26|141.101.98.26]] 22:05, 9 August 2020 (UTC)

These “weapons” seem strangely appropriate for xkcd’s stick figures... -cpl
: Agreed :)

Are we sure White Hat is holding empty set? There don't appear to be points extending outside the circle in which case I think he's actually holding Theta -jc

Can I use the LaTeX mathwitch? [[Special:Contributions/141.101.98.26|141.101.98.26]] 10:03, 8 August 2020 (UTC)

First time editor here,hope I get the notation right! Question on the pi link to wikipedia: I put in the double link to the main page and the disambiguation because unfortunately https://en.wikipedia.org/wiki/Pi_(disambiguation)#Mathematics doesn't include the mathematical constant definition (though it is listed at the top of the page). Thoughts? [[User:Alan g|Alan g]] ([[User talk:Alan g|talk]]) 10:38, 8 August 2020 (UTC)

I think that’s the is proportional to” symbol rather than just alpha. They are similar but have different Unicode symbols. Thoughts?--[[Special:Contributions/141.101.98.222|141.101.98.222]] 12:01, 8 August 2020 (UTC)
:You're definitely correct. (They don't even look that similar...) It's the direct proportion symbol, not the symbol for Alpha.
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 18:03, 8 August 2020 (UTC)
I don't think → is "implies", particularly as we've had ⇒ earlier. → is often used for "maps to", as in f: x → f(x) [[Special:Contributions/141.101.107.166|141.101.107.166]] 19:24, 8 August 2020 (UTC)
:→ and ⇒ often mean two different kinds of "implies". The single arrow is for the boolean operator that takes in two truth values and outputs a truth value. The double one is for "things on the left justify/prove things on the right", in somewhat of a metalanguage. Here's an example of two different ways of saying Modus Ponens with the operators: ((p→q) ∧p)→q vs p→q,p⇒q [[User:Alan g|Alan g]] ([[User talk:Alan g|talk]]) 03:52, 9 August 2020 (UTC)
Are we sure that is the multiplication sign (center dot)? The placement makes it seem more a decimal point. [[Special:Contributions/162.158.123.47|162.158.123.47]] 21:51, 8 August 2020 (UTC)
:Confusingly, math conventions in some countries use a low dot for multiplication, though it's not as common as it used to be. That's in addition to all the other things that bare dots can represent in math. Personally I can't "see" any particular set of semantics for that symbol, I just see a dot. [[Special:Contributions/162.158.186.136|162.158.186.136]] 22:51, 8 August 2020 (UTC)
We see a greater-than, but no less-than. Where would that appear? I think >≠<, in fact ><<, if wielded properly. Though if thrown, either/both could be a multi-use projectile... [[Special:Contributions/141.101.98.96|141.101.98.96]] 09:08, 9 August 2020 (UTC)
: Took me a little bit to figure out what you meant, but I think it hasn't been clarified which side is the point or sharp side, so until that is clarified "<"=">"

Anyone else think the title text is hinting at a pun? "I got scared because his weapon looked like treble" sort of thing?

Where is the opening parenthesis? [[Special:Contributions/172.69.33.223|172.69.33.223]] 21:43, 9 August 2020 (UTC)
: Here! (: [[Special:Contributions/162.158.154.131|162.158.154.131]] 09:33, 10 August 2020 (UTC)

If I could implement a line integral as a machine rather than a symbol, I'd use that to encircle my enemy. WIN! [[User:Cellocgw|Cellocgw]] ([[User talk:Cellocgw|talk]]) 13:15, 10 August 2020 (UTC)

i'm sure that the radix symbol could be used in a manner similar to sly cooper's crook [[Special: Contribuitions/138.186.224.65|138.186.224.65]] 13:32, 10 August 2020 (UTC)

The partial derivative could be used as a grappling hook, which is possibly why it's ranked where it is. I think Delta is higher than the A shape, because there isn't a chance of damage from push-back - both ends of the latter are pointy. [[Special:Contributions/172.69.63.237|172.69.63.237]] 18:20, 10 August 2020 (UTC)
== Would anyone else like to join me in creating an anti-Gamma interest group? ==

Just asking. [[Special:Contributions/172.69.33.223|172.69.33.223]] 21:47, 9 August 2020 (UTC)

Talk:2343: Mathematical Symbol Fight

2020-08-09T17:14:44Z

172.69.63.237: Added a few comments

Can I get aleph-null aleph-shaped throwing stars? [[User:LunarNapolean|LunarNapolean]] ([[User talk:LunarNapolean|talk]]) 20:18, 7 August 2020 (UTC)

Apologies to whoever added the "citation needed" that I stepped on. -- brad

That zeta looks conspicuously bad. I wonder if this comic will get a cleaned-up version uploaded. [[Special:Contributions/108.162.237.16|108.162.237.16]] 20:51, 7 August 2020 (UTC)

[[Megan]] usually has shoulder-length hair, so the person being attacked by Ponytail is probably not Megan... except in so far as all brunettes in this comic are called 'Megan'. [[User:LtPowers|LtPowers]] ([[User talk:LtPowers|talk]]) 20:53, 7 August 2020 (UTC)
:Is one of them [[Danish]]? And one of them Megan? [[Special:Contributions/172.69.33.121|172.69.33.121]] 22:49, 7 August 2020 (UTC)

I think Randall is underestimating the weapon utility of psi. There's a real-world martial arts [https://en.wikipedia.org/wiki/Sai_(weapon) weapon] that looks somewhat like it.[[Special:Contributions/172.69.68.197|172.69.68.197]] 22:04, 7 August 2020 (UTC)
:I think he’s also seriously underestimating the value of keeping your fingers attached to your hand. Swords have guards for a reason. I’d pick the contour integral over anything else there.

Considering the title text, a bass clef looks pretty formidable, close to a bat'leth. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 00:31, 8 August 2020 (UTC)
:Yes, but the treble clef is the one in the title text, and that’s nothing like a Klingon {{w|bat'leth}}. I removed the comment from the table. [[User:Adam1729|Adam1729]] ([[User talk:Adam1729|talk]]) 02:09, 8 August 2020 (UTC)

These “weapons” seem strangely appropriate for xkcd’s stick figures... -cpl
: Agreed :)

Are we sure White Hat is holding empty set? There don't appear to be points extending outside the circle in which case I think he's actually holding Theta -jc

Can I use the LaTeX mathwitch? [[Special:Contributions/141.101.98.26|141.101.98.26]] 10:03, 8 August 2020 (UTC)

First time editor here,hope I get the notation right! Question on the pi link to wikipedia: I put in the double link to the main page and the disambiguation because unfortunately https://en.wikipedia.org/wiki/Pi_(disambiguation)#Mathematics doesn't include the mathematical constant definition (though it is listed at the top of the page). Thoughts? [[User:Alan g|Alan g]] ([[User talk:Alan g|talk]]) 10:38, 8 August 2020 (UTC)

I think that’s the is proportional to” symbol rather than just alpha. They are similar but have different Unicode symbols. Thoughts?--[[Special:Contributions/141.101.98.222|141.101.98.222]] 12:01, 8 August 2020 (UTC)
:You're definitely correct. (They don't even look that similar...) It's the direct proportion symbol, not the symbol for Alpha.
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 18:03, 8 August 2020 (UTC)
I don't think → is "implies", particularly as we've had ⇒ earlier. → is often used for "maps to", as in f: x → f(x) [[Special:Contributions/141.101.107.166|141.101.107.166]] 19:24, 8 August 2020 (UTC)
:→ and ⇒ often mean two different kinds of "implies". The single arrow is for the boolean operator that takes in two truth values and outputs a truth value. The double one is for "things on the left justify/prove things on the right", in somewhat of a metalanguage. Here's an example of two different ways of saying Modus Ponens with the operators: ((p→q) ∧p)→q vs p→q,p⇒q [[User:Alan g|Alan g]] ([[User talk:Alan g|talk]]) 03:52, 9 August 2020 (UTC)
Are we sure that is the multiplication sign (center dot)? The placement makes it seem more a decimal point. [[Special:Contributions/162.158.123.47|162.158.123.47]] 21:51, 8 August 2020 (UTC)
:Confusingly, math conventions in some countries use a low dot for multiplication, though it's not as common as it used to be. That's in addition to all the other things that bare dots can represent in math. Personally I can't "see" any particular set of semantics for that symbol, I just see a dot. [[Special:Contributions/162.158.186.136|162.158.186.136]] 22:51, 8 August 2020 (UTC)
We see a greater-than, but no less-than. Where would that appear? I think >≠<, in fact ><<, if wielded properly. Though if thrown, either/both could be a multi-use projectile... [[Special:Contributions/141.101.98.96|141.101.98.96]] 09:08, 9 August 2020 (UTC)
: Took me a little bit to figure out what you meant, but I think it hasn't been clarified which side is the point or sharp side, so until that is clarified "<"=">"

Anyone else think the title text is hinting at a pun? "I got scared because his weapon looked like treble" sort of thing?