Wikipedia:Reference desk/Archives/Science/2020 December 26

= December 26 =

Comparison of RNA vaccines and RNA viruses
How do they compare? Can the former reproduce, at least to some degree, once inside the human body? Some of the latter cause cancer, how can we discard that the former also won't? Is their mechanism of action similar? Both articles might improve with a sub-section around these issues. --Bumptump (talk) 14:40, 26 December 2020 (UTC)
 * You should read the respective articles. Ruslik_ Zero 17:16, 26 December 2020 (UTC)
 * Always a good idea, but do they address the specific questions posed by the OP? --Lambiam 23:36, 26 December 2020 (UTC)
 * As implied above, the articles need more content regarding these questions. Ruslik should read the respective articles to see by himself. --Bumptump (talk) 23:51, 26 December 2020 (UTC)
 * The last two paragraphs in 'Mechanism' section answer all your questions. Ruslik_ Zero 20:23, 27 December 2020 (UTC)
 * They describe how the vaccine is intended to work. They do not contain an assurance that no RNA replication can take place. If they somehow imply this, well, then this implication is rather... implicit. I can understand that people want to be sure that this cannot happen. Assurances by scientists saying, "trust us, nothing can go wrong", are probably not an effective approach. Note also that until November 27 the lead stated that the cells are "reprogrammed" by injecting the vaccine, which was not helpful. --Lambiam 23:52, 27 December 2020 (UTC)
 * Sure, some scientists can have trouble communicating to the general public because they tend to forget not everyone has their level of background knowledge. An RNA vaccine would have to include an RNA-dependent polymerase or something like a retrotransposon to even hypothetically get a cell to make copies of the RNA. "Typically", gene information only moves one-way in cells, DNA to RNA to protein. Free RNA is rapidly broken down by cells. The central challenge of RNA vaccine development has been actually getting the RNA to persist in a cell long enough to get translated, which was done with the modRNA technique (which is on the Main Page today), selectively modifying the RNA so it's more resistant to degradation but still able to get translated by ribosomes. --47.152.93.24 (talk) 02:14, 28 December 2020 (UTC)
 * And some respondents here can have trouble communicating with questioners, dismissing reasonable questions as if they display an unconscionable ignorance and this reference desk has no raison d'être other than to belittle questioners. --Lambiam 12:15, 28 December 2020 (UTC)
 * The intent of existing RNA vaccines is to get the RNA into your cells and get it translated by ribosomes into the protein it codes for. Whether that counts as "reproduction" is up to you. This is where we run up against human language being vague. Viruses themselves are just nucleic acid and proteins in a package, and don't do anything outside of a cell, which is why many people don't consider them really "alive". Oncoviruses can cause cancer by trying to insert their genes into the cell's DNA or by otherwise messing with gene transcription and regulation. Doing the former requires enzymes to splice the viral genes into the cell's DNA (retroviruses use a reverse transcriptase). The latter could potentially be caused by just RNA, but it'd probably have to be complex RNA encoding things like ribozymes. This could potentially be used to treat cancer or other diseases as well. But for producing immunity to a disease, the vaccine will generally only contain genes for antigens to elicit an immune response against them. The RNA vaccines for COVID-19 just contain the gene for the viral "spike protein" that binds to cells to infect them. --47.152.93.24 (talk) 03:21, 27 December 2020 (UTC)