Tysabri is currently administered via IV in a number of hospitals in Ireland. These injections will be given by a health professional but will be administered in less time and may be a preferable administration method for some.
Clinical trials have shown that monthly subcutaneous injections of Tysabri are as effective as monthly infusions at reducing relapses and lesions seen on MRI scans. About 7% of people experienced mild or moderate injection site reactions when having a subcutaneous injection of Tysabri.
Further info:
https://clinicaltrials.gov/ct2/show/NCT00559702?
https://clinicaltrials.gov/ct2/show/NCT01405820