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



               SUPPLEMENT DATED JULY 30, 2002 TO THE PROSPECTUS OF
               MORGAN STANLEY VARIABLE INVESTMENT SERIES -- CLASS X
                              HIGH YIELD PORTFOLIO
                                DATED MAY 1, 2002

         The first sentence in the first paragraph under the heading "Principal
Investment Strategies" in the sub-section of the Prospectus pertaining to the
High Yield Portfolio in the section of the Prospectus titled "THE PORTFOLIOS" is
hereby deleted and replaced with the following:

         The Portfolio will normally invest at least 80% of its assets in
         fixed-income securities (including zero coupon securities) rated below
         Baa by Moody's or below BBB by S&P or in nonrated securities considered
         by the Investment Manager to be appropriate investments for the
         Portfolio.

         The first point under the third paragraph under that heading is hereby
deleted and replaced with the following:

         o    Higher rated fixed-income securities -- The Portfolio may invest
              in securities rated Baa or BBB or higher (or, if not rated,
              determined to be of comparable quality) when the Investment
              Manager believes that such securities may produce attractive
              yields.

                            ------------------------

               SUPPLEMENT DATED JULY 30, 2002 TO THE PROSPECTUS OF
               MORGAN STANLEY VARIABLE INVESTMENT SERIES -- CLASS Y
                              HIGH YIELD PORTFOLIO
                                DATED MAY 1, 2002

         The first sentence in the first paragraph under the heading "Principal
Investment Strategies" in the sub-section of the Prospectus pertaining to the
High Yield Portfolio in the section of the Prospectus titled "THE PORTFOLIOS" is
hereby deleted and replaced with the following:

         The Portfolio will normally invest at least 80% of its assets in
         fixed-income securities (including zero coupon securities) rated below
         Baa by Moody's or below BBB by S&P or in nonrated securities considered
         by the Investment Manager to be appropriate investments for the
         Portfolio.

         The first point under the third paragraph under that heading is hereby
deleted and replaced with the following:

         o    Higher rated fixed-income securities -- The Portfolio may invest
              in securities rated Baa or BBB or higher (or, if not rated,
              determined to be of comparable quality) when the Investment
              Manager believes that such securities may produce attractive
              yields.