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Most childhood vaccines are 90–99% effective in preventing disease. Side effects are rarely serious.
Thyroid conditions may make getting pregnant impossible.
Signs and symptoms of a drug overdose include losing consciousness, fever or sweating, breathing problems, abnormal pulse, and changes in skin color.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Long-term mental and physical effects from substance abuse include: paranoia, psychosis, immune deficiencies, and organ damage.
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