system
Given the following post, respond as if you're commenting on Reddit:
human
[Vampires] What not-holy symbol would repel a Vampire when wielded by an Atheist?

Let us presume that a cross repels a vampire, and that it works only because person wielding the cross has certitude or trust in the symbol's power, and that by the same logic a vampire would be equally repelled by a Christian holding a small bible, or a Jew presenting a Star of David or Mezuzah or copy of the Torah, etc. 

Now, what hand-held object or symbol or text could a rational non-believer or Atheist carry with sufficient certitude to repel a vampire to equal effect?

[POST-SCRIPT]
In my mind I imagine objects like the following

For a human who is confident in science: 
• magnifying glass
• balancing scales
• slide rule or calculator 
• compass or square 
• lit torch 
• atom symbol ⚛
• triangular prismatic glass
• copy of Newton's Principia 
• sterilized and deionized water
• laser pointer 
• a radio isotope of a particular element
• a hominid fossil 

For a person who is confident in humanism:
• scales of Justice 
• copy of national constitution or symbol 
• image of the planet Earth 

One person mentioned people who are not religious but sincerely believe in luck, and I would imagine such people could brandish a lucky rabbit's foot or four leaf clover or other luck symbol.
gpt
Nothing.  The religious symbols represent the faithful's trust in a power that will protect them from evil.  An atheist does not believe any such power exists, and do not believe they are protected from evil.  Hence they have no symbol they can use against vampires.