Do all coronavirus vaccines contain graphene, mercury, and aluminum? No, that's not true: according to the Centers for Disease Control's Vaccine portal, vaccines such as Pfizer/BioNTech, Moderna, and Johnson & Johnson/Janssen do not contain graphene, mercury, and aluminum.
The story appeared in a TikTok video (archived here) under the title "Why graphene, mercury, and aluminum in vaccines?".
The video included this frame:
(Source: TikTok screnshot taken Monday, May 22 at 12:02 PST)
In this article, you can find the entire list of ingredients for the coronavirus vaccine. You won't find anything about graphene, mercury, and aluminum.
In the same year (2021), a similar claim was made by Karen Kingston, a former Pfizer employee and current analyst for the pharmaceutical and medical device industries. She claimed that graphene oxide is used in coronavirus vaccines. However, Lead Stories debunked this claim. The press service of vaccine manufacturing companies replied that they do not use this ingredient in vaccines.
It turned out Karen Kingston sold Viagra™ for Pfizer and did not work on the vaccine.
Here is the video which explains how COVID-19 vaccines work. The work of the vaccine has nothing to do with the conspiracy theory hinted at by the author of the video.