Filed Pursuant to Rule 497(e)
                                                Registration File No.: 2-82510



              SUPPLEMENT DATED JULY 26, 2001 TO THE PROSPECTUS OF
          MORGAN STANLEY VARIABLE INVESTMENT SERIES -- CLASS X SHARES
                               DATED MAY 1, 2001


     With respect to the Utilities Portfolio, the following paragraph is added
after the second paragraph in the section of the Prospectus titled "PRINCIPAL
INVESTMENT STRATEGIES":


     The Portfolio may invest in asset-backed securities. Asset-backed
     securities represent an interest in a pool of assets such as a pool of
     power generation assets or other utility assets or utility related assets,
     automobile and credit card receivables or home equity loans that have been
     securitized in pass through structures similar to mortgage-backed
     securities. These types of pass through securities provide for monthly
     payments that are a "pass through" of the monthly interest and principal
     payments made by the individual borrowers on the pooled investments.


     With respect to the Utilities Portfolio, the following paragraph is added
after the sixth paragraph in the section of the Prospectus titled "SUMMARY OF
PRINCIPAL RISKS":


     There are also particular risks associated with the Portfolio's investments
     in asset-backed securities. For example, asset-backed securities are
     subject to prepayment risk and in some cases may be more volatile and less
     liquid than other traditional types of debt securities.


     Investors in the Utilities Portfolio are directed to the paragraph titled
"ASSET-BACKED SECURITIES" under the section of the Prospectus titled
"ADDITIONAL RISK INFORMATION."