<PAGE>
Filed Pursuant to Rule 497
Registration File No.: 2-82510
SUPPLEMENT TO THE PROSPECTUS OF
MORGAN STANLEY DEAN WITTER VARIABLE INVESTMENT SERIES
DATED NOVEMBER 2, 1998
NEW MANAGEMENT FEE BREAKPOINTS FOR DIVIDEND GROWTH, GLOBAL DIVIDEND
GROWTH, MONEY MARKET, STRATEGIST AND UTILITIES PORTFOLIOS. The section of the
Prospectus entitled "The Fund and its Management" is revised to reflect that,
effective May 1, 1999, the Board of Trustees of the Fund has amended the Fund's
Investment Management Agreement to reduce the compensation received by the
Investment Manager from the following Portfolios for assets exceeding specified
levels, so that the compensation under the Agreement will be calculated daily
by applying the following annual rates to the Portfolio's net assets determined
as of the close of each business day:
o DIVIDEND GROWTH PORTFOLIO -- 0.625% of the portion of daily net assets not
exceeding $500 million; 0.50% of the next $500 million; 0.475% of the next
$1 billion; 0.45% of the next $1 billion; and 0.425% of the portion of daily
net assets exceeding $3 billion.
o GLOBAL DIVIDEND GROWTH PORTFOLIO -- 0.75% of the portion of daily net assets
not exceeding $1 billion; and 0.725% of the portion of daily net assets
exceeding $1 billion.
o MONEY MARKET PORTFOLIO -- 0.50% of the portion of daily net assets not
exceeding $500 million; 0.425% of the next $250 million; and 0.375% of the
portion of daily net assets exceeding $750 million.
o STRATEGIST PORTFOLIO -- 0.50% of the portion of daily net assets not
exceeding $1.5 billion; and 0.475% of the portion of daily net assets
exceeding $1.5 billion.
o UTILITIES PORTFOLIO -- 0.65% of the portion of daily net assets not
exceeding $500 million; 0.55% of the next $500 million; and 0.525% of the
portion of daily net assets exceeding $1 billion.
PROPOSED CHANGES PERTAINING TO THE UTILITIES PORTFOLIO. On April 22, 1999,
the Board of Trustees of the Fund approved the following changes respecting the
Utilities Portfolio of the Fund:
The Board unanimously recommended that the Portfolio's shareholders
approve changing the Portfolio's investment objective to: "seek both capital
appreciation and current income." Currently, the Portfolio's objective is to
"provide current income and long-term growth of income and capital, by
investing primarily in equity and fixed-income securities of companies engaged
in the public utilities industry." Adoption of this change would have the
effect of (i) eliminating long-term growth of income as an objective of the
Portfolio and (ii) permitting the Portfolio to invest primarily in the entire
utilities industry, as opposed to the more limited public utilities industry.
A proxy statement fully describing the proposed change in objective and
the reasons for the Board's action will be distributed to the Portfolio's
shareholders.
April 22, 1999
# 40171
