When you first create an Apple ID (using your email address) a verification email is sent to that address. If you sign in to your Apple ID from the link in that email, the email address RSV antibody (IgG) ELISA kit is verified as the primary email address for your Apple ID. You can also resend the email verification if the email address is not verified:
Sign in to My Apple ID to manage your account information b1j3c6c.
Click Resend under Primary Email Address.