Clinical trials...? Just read the ingredients and clinical study results to see if it's safe to inject;

GARDASIL is a sterile suspension for intramuscular administration. Each 0.5-mL dose contains
approximately 20 mcg of HPV 6 L1 protein, 40 mcg of
HPV 11 L1 protein, 40 mcg of HPV 16 L1 protein,
and 20 mcg of HPV 18 L1 protein.
Each 0.5-mL dose of the vaccine contains appr
oximately 225 mcg of aluminum (as Amorphous
Aluminum Hydroxyphosphate Sulfate adjuv
ant), 9.56 mg of sodium chloride,
0.78 mg of L-histidine,
50 mcg of polysorbate 80, 35 mcg of sodium borate, <7
mcg yeast protein/dose, and water for injection.
The product does not contain a preservative or antibiotics.

Source

From what I just scanned over in their own documents, they did a short term evaluation on a little over 1500 people in 2 "clinical" studies with horrible results...

Looks good to me.