The 2012-2013 influenza vaccine will protect against H1N1, as well as the common influenza B virus and an H3N2 virus. It's available in two varieties — intranasal and injectable. The intranasal form (sprayed into the nose) is generally not recommended for those affected by neuromuscular disease.
Check with your doctor before obtaining any vaccine, especially if you're affected by myasthenia gravis, polymyositis, dermatomyositis, or taking immune-suppressing medications such as corticosteroids (e.g. prednisone, deflazacort, prednisolone).
If your current health coverage doesn't include seasonal flu vaccines as a preventive health benefit, MDA's Flu Shot Program can help.