<PAGE>   1
    As filed with the Securities and Exchange Commission on February 12, 1999
                                                Registration No. 333- __________

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

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8

                             REGISTRATION STATEMENT
                                    UNDER THE
                             SECURITIES ACT OF 1933


                                  ORAVAX, INC.
--------------------------------------------------------------------------------
               (Exact name of issuer as specified in its charter)


<TABLE>
<CAPTION>
<S>                                               <C>
           Delaware                                    04-3085209   
-------------------------------             ------------------------------------                      
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)


38 Sidney Street, Cambridge, Massachusetts                02139    
------------------------------------------              ---------    
 (Address of Principal Executive Offices)               (Zip Code)
</TABLE>


                       401(K) SAVINGS AND RETIREMENT PLAN
--------------------------------------------------------------------------------
                            (Full Title of the Plan)


                           John M. Westcott, Jr., Esq.
                              c/o Hale and Dorr LLP
                                 60 State Street
                           Boston, Massachusetts 02109
--------------------------------------------------------------------------------
                     (Name and Address of Agent for Service)


                                 (617) 526-6000
--------------------------------------------------------------------------------
          (Telephone Number, Including Area Code, of Agent For Service)



<PAGE>   2





                         CALCULATION OF REGISTRATION FEE


<TABLE>
<CAPTION>

=======================================================================================================
                                                 Proposed Maximum         Proposed
         Title of                                    Offering             Maximum
        Securities               Amount              Price Per           Aggregate           Amount
          to be                  to be               Share (1)            Offering      of Registration
        Registered             Registered                                Price (1)            Fee
-------------------------------------------------------------------------------------------------------
<S>                          <C>                       <C>                <C>                <C>
     Common Stock,
     $.001 par value         85,000 shares             $0.64              $54,400            $16.00
=======================================================================================================
</TABLE>

(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rule 457(c) and (h) and based on the average of the reported 
    high and low sale prices of the registrant's Common Stock on the NASD OTC 
    Bulletin Board on February 5, 1999.

                                       2
<PAGE>   3





                     STATEMENT OF INCORPORATION BY REFERENCE

         This Registration Statement on Form S-8 (the "Registration Statement")
incorporates by reference the contents of the Registration Statement on Form
S-8, File No. 33-94988, filed by OraVax, Inc., a Delaware corporation (the
"Company"), with the Securities and Exchange Commission on July 26, 1995,
relating to the Company's 401(k) Savings and Retirement Plan.



                                       3
<PAGE>   4


                                   SIGNATURES


         Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on the 10 day
of February, 1999.

                                             ORAVAX, INC.


                                             By:  /s/ Lance K. Gordon 
                                                  ------------------------------
                                                  Lance K. Gordon,
                                                  President and
                                                  Chief Executive Officer


                                POWER OF ATTORNEY

         We, the undersigned Directors and Officers of the Company hereby
constitute Lance K. Gordon, Brigid A. Makes and John M. Westcott, Jr., and each
of them singly, our true and lawful attorneys with full power to them, and each
of them singly, to sign for us and in our names in the capacities indicated
below, the Registration Statement on Form S-8 filed herewith and any and all
subsequent amendments to said Registration Statement, and generally to do all
such things in our names and behalf in our capacities as Directors and Officers
to enable OraVax, Inc. to comply with all requirements of the Securities Act of
1933, as amended, and all requirements of the Securities and Exchange
Commission, hereby ratifying and confirming our signatures as they may be signed
by said attorneys, or any of them, to said Registration Statement and any and
all amendments thereto.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.

                                       4
<PAGE>   5

<TABLE>
<CAPTION>

Signature                                      Title                      Date
---------                                      -----                      ----
<S>                                        <C>                         <C>
(i)    Principal executive                                          )
       officer:                                                     )
                                                                    )
                                                                    )
 /s/ Lance K. Gordon                       President and            )
------------------------------------       Chief Executive          )
Lance K. Gordon                            Officer                  )
                                                                    )
                                                                    )
(ii)   Principal financial and                                      )
       accounting officer:                                          )
                                                                    )
                                                                    )
 /s/ Brigid A. Makes                       Vice President, Finance  )
------------------------------------       and Chief Financial      )
Brigid A. Makes                            Other                    )
                                                                    )
                                                                    )
(iii)  A majority of the                                            )
       Board of Directors:                                          )
                                                                    )
                                                                    )
 /s/ Lance K. Gordon                        Director                ) February 10, 1999
------------------------------------                                )
Lance K. Gordon                                                     )
                                                                    )
                                                                    )
/s/ Andre L. Lamotte                        Director                )
------------------------------------                                )
Andre L. Lamotte                                                    )
                                                                    )
                                                                    )
                                            Director                )
------------------------------------                                )
Douglas MacMaster                                                   )
                                                                    )
                                                                    )
 /s/ Allen Misher                           Director                )   
------------------------------------                                )
Allen Misher
</TABLE>


<PAGE>   6


                                  EXHIBIT INDEX

<TABLE>
<CAPTION>

Exhibit No.                       Description                           Page
-----------                       -----------                           ----
<S>                 <C>                                                 <C>
   4.1*             Second Amended and Restated Certificate              --
                    of Incorporation of the Registrant.

   4.2*             Amended and Restated By-Laws of the                  --
                    Registrant

   5.1              Opinion of Hale and Dorr LLP.                         7 

  23.1              Consent of PricewaterhouseCoopers LLP                 8

  23.2              Consent of Hale and Dorr LLP (included in             7
                    Exhibit 5.1).

  24                Power of Attorney (included on page                   4
                    3 of this Registration Statement).
</TABLE>

---------

*  Incorporated herein by reference to the Company's Registration Statement
   on Form S-1, as amended (File No. 33-90936).
[{"type": "S-8", "sequence": "1", "description": "ORAVAX, INC.", "secsgml_size_bytes": 10164}]
{"company-data": {"conformed-name": "ORAVAX INC /DE/", "cik": "0000900122", "assigned-sic": "2836", "irs-number": "043085209", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-72285", "film-number": "99536678"}, "business-address": {"street1": "38 SIDNEY ST 4TH FLOOR", "city": "CAMBRIDGE", "state": "MA", "zip": "02139", "phone": "6175266000"}}
1
    As filed with the Securities and Exchange Commission on February 12, 1999
                                                Registration No. 333- __________

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

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM S-8

                             REGISTRATION STATEMENT
                                    UNDER THE
                             SECURITIES ACT OF 1933

                                  ORAVAX, INC.
--------------------------------------------------------------------------------
               (Exact name of issuer as specified in its charter)
Delaware                                    04-3085209   
-------------------------------             ------------------------------------                      
(State or other jurisdiction of             (I.R.S. Employer Identification No.)
incorporation or organization)

38 Sidney Street, Cambridge, Massachusetts                02139    
------------------------------------------              ---------    
 (Address of Principal Executive Offices)               (Zip Code)
401(K) SAVINGS AND RETIREMENT PLAN
--------------------------------------------------------------------------------
                            (Full Title of the Plan)

                           John M. Westcott, Jr., Esq.
                              c/o Hale and Dorr LLP
                                 60 State Street
                           Boston, Massachusetts 02109
--------------------------------------------------------------------------------
                     (Name and Address of Agent for Service)

                                 (617) 526-6000
--------------------------------------------------------------------------------
          (Telephone Number, Including Area Code, of Agent For Service)
2

                         CALCULATION OF REGISTRATION FEE
=======================================================================================================
                                                 Proposed Maximum         Proposed
         Title of                                    Offering             Maximum
        Securities               Amount              Price Per           Aggregate           Amount
          to be                  to be               Share (1)            Offering      of Registration
        Registered             Registered                                Price (1)            Fee
-------------------------------------------------------------------------------------------------------
Common Stock,
     $.001 par value         85,000 shares             $0.64              $54,400            $16.00
=======================================================================================================
(1) Estimated solely for the purpose of calculating the registration fee
    pursuant to Rule 457(c) and (h) and based on the average of the reported 
    high and low sale prices of the registrant's Common Stock on the NASD OTC 
    Bulletin Board on February 5, 1999.

                                       2
3

                     STATEMENT OF INCORPORATION BY REFERENCE

         This Registration Statement on Form S-8 (the "Registration Statement")
incorporates by reference the contents of the Registration Statement on Form
S-8, File No. 33-94988, filed by OraVax, Inc., a Delaware corporation (the
"Company"), with the Securities and Exchange Commission on July 26, 1995,
relating to the Company's 401(k) Savings and Retirement Plan.

                                       3
4

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act of 1933, the Company
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Boston, Commonwealth of Massachusetts, on the 10 day
of February, 1999.

                                             ORAVAX, INC.

                                             By:  /s/ Lance K. Gordon 
                                                  ------------------------------
                                                  Lance K. Gordon,
                                                  President and
                                                  Chief Executive Officer

                                POWER OF ATTORNEY

         We, the undersigned Directors and Officers of the Company hereby
constitute Lance K. Gordon, Brigid A. Makes and John M. Westcott, Jr., and each
of them singly, our true and lawful attorneys with full power to them, and each
of them singly, to sign for us and in our names in the capacities indicated
below, the Registration Statement on Form S-8 filed herewith and any and all
subsequent amendments to said Registration Statement, and generally to do all
such things in our names and behalf in our capacities as Directors and Officers
to enable OraVax, Inc. to comply with all requirements of the Securities Act of
1933, as amended, and all requirements of the Securities and Exchange
Commission, hereby ratifying and confirming our signatures as they may be signed
by said attorneys, or any of them, to said Registration Statement and any and
all amendments thereto.

         Pursuant to the requirements of the Securities Act of 1933, this
Registration Statement has been signed below by the following persons in the
capacities and on the dates indicated.

                                       4
5
Signature                                      Title                      Date
---------                                      -----                      ----
(i)    Principal executive                                          )
       officer:                                                     )
                                                                    )
                                                                    )
 /s/ Lance K. Gordon                       President and            )
------------------------------------       Chief Executive          )
Lance K. Gordon                            Officer                  )
                                                                    )
                                                                    )
(ii)   Principal financial and                                      )
       accounting officer:                                          )
                                                                    )
                                                                    )
 /s/ Brigid A. Makes                       Vice President, Finance  )
------------------------------------       and Chief Financial      )
Brigid A. Makes                            Other                    )
                                                                    )
                                                                    )
(iii)  A majority of the                                            )
       Board of Directors:                                          )
                                                                    )
                                                                    )
 /s/ Lance K. Gordon                        Director                ) February 10, 1999
------------------------------------                                )
Lance K. Gordon                                                     )
                                                                    )
                                                                    )
/s/ Andre L. Lamotte                        Director                )
------------------------------------                                )
Andre L. Lamotte                                                    )
                                                                    )
                                                                    )
                                            Director                )
------------------------------------                                )
Douglas MacMaster                                                   )
                                                                    )
                                                                    )
 /s/ Allen Misher                           Director                )   
------------------------------------                                )
Allen Misher
6

                                  EXHIBIT INDEX
Exhibit No.                       Description                           Page
-----------                       -----------                           ----
4.1*             Second Amended and Restated Certificate              --
                    of Incorporation of the Registrant.

   4.2*             Amended and Restated By-Laws of the                  --
                    Registrant

   5.1              Opinion of Hale and Dorr LLP.                         7 

  23.1              Consent of PricewaterhouseCoopers LLP                 8

  23.2              Consent of Hale and Dorr LLP (included in             7
                    Exhibit 5.1).

  24                Power of Attorney (included on page                   4
                    3 of this Registration Statement).
---------

*  Incorporated herein by reference to the Company's Registration Statement
   on Form S-1, as amended (File No. 33-90936).