Why do I have lots of warts all over my body?

May just be you. I'm going to assume these really are warts, and not some less familiar skin disease. Some folks simply get lots of these, and you'll spend time having them removed by whatever means you and your physician find most appropriate. People who are immunosuppressed for transplants or other reasons sometimes get grotesque numbers of warts, but without other evidence, don't assume you're compromised.
Lack of immunity. To hpv virus that cause warts , speak to your doctor still you may be a candidate for vaccination , how ever it covers only 4 genotypes of genital warts only, .