The sign for "prevent" can also be used to mean "block" or
"protect."
You could even combine it with a sign like "INJECT" or "take-PILL"
to create the meaning "inoculate."
PREVENT / BLOCK / PROTECT:
You can learn
American Sign Language (ASL) online at American Sign Language University ™
ASL resources by Lifeprint.com © Dr. William Vicars