As filed with the Securities and Exchange Commission on October 2, 2006

                                                   Registration No. 333-______

                UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                             ______________________

                                    FORM S-8
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                             ______________________

                                  ACAMBIS PLC
             (Exact name of registrant as specified in its charter)

                England and Wales                               N/A
 (State or other jurisdiction of Incorporation or  (IRS Employer Identification
                  organization)                               Number)


                 Peterhouse Technology Park, 100 Fulbourn Road
                       Cambridge, CB1 9PT, United Kingdom
                    (Address of principal executive offices)

               The Acambis plc 2006 Unapproved Share Option Plan
                           (Full title of the Plans)

                                 David Lawrence
                            Chief Financial Officer
                 Peterhouse Technology Park, 100 Fulbourn Road
                       Cambridge, CB1 9PT, United Kingdom
                              011-44-1223-275-300
           (Name, address and telephone number of agent for service)

                                    Copy to:
                           Kristian E. Wiggert, Esq.
                            Morrison & Foerster MNP
                   7th Floor, CityPoint, One Ropemaker Street
                        London, EC2Y 9AW, United Kingdom
                              011-44-207-920-4000
                        _______________________________

                        CALCULATION OF REGISTRATION FEE


                                                                         
=============================================================================================
                                        Proposed maximum   Proposed maximum        Amount of
Title of Securities    Amount to be      offering price   aggregate offering     registration
 to be Registered      registered (1)     per share (3)        price (3)             fee
---------------------------------------------------------------------------------------------
Ordinary Shares,
nominal value
10 pence each       2,000,000 shares (2)     $2.82             $5,640,000            $604
---------------------------------------------------------------------------------------------


(1) Pursuant to Rule 416(a) under the Securities Act of 1933, as amended (the
"Securities Act"), this Registration Statement includes an indeterminate number
of additional shares which may be offered and issued to prevent dilution from
stock splits, stock dividends or similar transactions as provided in the
above-referenced plans.

(2) This total represents the amount of shares to be registered for issuance
pursuant to the Registrant's 2006 Unapproved Share Option Plan.

(3)   Estimated solely for the purpose of calculating the registration fee.
Pursuant to Rule 457(c) and Rule 457(h) under the Securities Act, the proposed
maximum offering price per share and the proposed maximum aggregate offering
price have been determined on the basis of the average of the high (GBP1.50) and
low (GBP1.468) sale prices reported on the London Stock Exchange on September
26, 2006. The U.S. dollar amount was calculated using the Noon exchange rate for
pounds (GBP1 = $1.8954) as reported by the Federal Reserve Bank of New York on
September 26, 2006.



                                     PART I
                          INFORMATION REQUIRED IN THE
                            SECTION 10(a) PROSPECTUS

The documents containing the information specified in this Part I of Form S-8
(plan information and registrant information and employee plan annual
information) will be sent or given to employees as specified by Securities and
Exchange Commission Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission (the "Commission") either as part of this
Registration Statement or as prospectuses or prospectus supplements pursuant to
Rule 424. These documents and the documents incorporated by reference in this
Registration Statement pursuant to Item 3 of Part II of this Form S-8, taken
together, constitute a prospectus that meets the requirements of Section 10(a)
of the Securities Act of 1933, as amended (the "Securities Act").


                                    PART II
                          INFORMATION REQUIRED IN THE
                             REGISTRATION STATEMENT

Item 3. Incorporation of Documents by Reference.

The following documents filed by the Registrant with the Commission are
incorporated by reference herein:

a. The Registrant's Annual Report on Form 20-F for the year ended December 31,
2005 filed on June 28, 2006, which includes audited financial statements for
such year.

b. All other reports filed by the Registrant pursuant to Section 13(a) or 15(d)
of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), since
December 31, 2005.

c. The description of the Registrant's Ordinary Shares, nominal value 10 pence
per share, contained in the Registration Statement on Form F-4, as filed with
the Commission on February 10, 1999 (File No. 333-72077), including any
amendment or report filed for the purpose of updating such description.

All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and
15(d) of the Exchange Act after the date of this Registration Statement, and
prior to the filing of a post-effective amendment which indicates that all
securities offered hereby have been sold or which de-registers all securities
then remaining unsold, shall be deemed to be incorporated by reference in this
Registration Statement and to be a part hereof from the date of filing of such
documents. Any statement contained in a document incorporated by reference
herein shall be deemed to be modified or superseded for purposes of this
Registration Statement to the extent that a statement contained herein or in any
other subsequently filed document which also is or is deemed to be incorporated
by reference herein modifies or supersedes such statement. Any statement so
modified or superseded shall not be deemed, except as so modified or superseded,
to constitute a part of this Registration Statement.

Item 4. Description of Securities.

Not applicable.

Item 5. Interests of Named Experts and Counsel.

Not applicable.

Item 6. Indemnification of Directors and Officers.

Articles 225 and 226 of the Registrant's Articles of Association provide:

"225 Directors and secretaries may be indemnified subject to the Statutes

"Subject to the provisions of the Statutes, but without prejudice to any
indemnity to which the person concerned may otherwise be entitled, every
director or other officer of the Company (other than any person (whether an
officer or not) engaged by the Company as auditor) shall be indemnified out of
the assets of the Company against any liability incurred by him for negligence,
default, breach of duty or breach of trust in relation to the affairs of the
Company, provided that this Article 225 shall be deemed not to provide for, or
entitle any such person to, indemnification to the extent that it would cause
this Article 225 or any element of it, to be treated as void under the 1985 Act
or otherwise under the Statutes."

"226 Power to purchase and maintain insurance

"Without prejudice to the provisions of Article 225, the Directors shall have
power to purchase and maintain, at the cost of the Company, insurance for, or
for the benefit of, any persons who are or were at any time Directors, officers
or employees of the Company, or of any other company or undertaking which is (a)
the holding company or parent undertaking of the Company or (b) a subsidiary or
subsidiary undertaking of the Company or of such holding company or parent
undertaking or any such holding company or parent undertaking or subsidiary of
subsidiary undertaking or in which the Company or such holding company or parent
undertaking or subsidiary or subsidiary undertaking has any interest whether
directly or indirectly, or who are or were at any time trustees of any
retirement benefits scheme or employees' share scheme in which employees of the
Company or of any such other company or undertaking are interested, including
(without prejudice to the generality of the foregoing) insurance against any
liability incurred by such persons in respect of any act or omission in the
actual or purported execution and/or discharge of their duties and/or the
exercise or purported exercise of their powers and/or otherwise in relation to
their duties, powers or offices in relation to the Company or any such other
company or undertaking, retirement benefit scheme or employees' share scheme."

Pursuant to the provisions of Section 310(3) of the Companies Act 1985 (as
amended by the Companies Act 1989) the Company may purchase and maintain
insurance to indemnify any director, officer, manager or auditor of the Company.
Section 310 of the Companies Act 1985 (as amended by Section 137 of the
Companies Act 1989) provides as follows:

"310. Provisions protecting auditors from liability

(1) This section applies to any provision, whether contained in a company's
articles or in any contract with the company or otherwise, for exempting any
...... person (whether an officer or not) employed by the company as auditor
from, or indemnifying him against, any liability which by virtue of any rule of
law would otherwise attach to him in respect of any negligence, default, breach
of duty or breach of trust of which he may be guilty in relation to the company.

(2) Except as provided by the following subsection, any such provision is void.

(3) This section does not prevent a company -

(a) from purchasing and maintaining for any such ..... auditor insurance against
any such liability, or

(b) from indemnifying any such ..... auditor against any liability incurred by
him -

(i) in defending any proceedings (whether civil or criminal) in which judgment
is given in his favour or he is acquitted, or

(ii) in connection with any application under section 727 (general power to
grant relief in case of honest and reasonable conduct) in which relief is
granted to him by the court."

Section 727 of the Companies Act 1985 provides as follows:

"727 Power of court to grant relief in certain cases

(1) If in any proceedings for negligence, default, breach of duty or breach of
trust against an officer of a company or a person employed by a company as
auditor (whether he is or is not an officer of the company) it appears to the
court hearing the case that that officer or person is or may be liable in
respect of the negligence, default, breach of duty or breach of trust, but that
he has acted honestly and reasonably, and that having regard to all the
circumstances of the case (including those connected with his appointment) he
ought fairly to be excused for the negligence, default, breach of duty or breach
of trust, that court may relieve him, either wholly or partly, from his
liability in such terms as it thinks fit.

(2) If any such officer or person as above- mentioned has reason to apprehend
that any claim will or might be made against him in respect of any negligence,
default, breach of duty or breach of trust, he may apply to the court for
relief; and the court on the application has the same power to relieve him as
under this section it would have had if it had been a court before which
proceedings against that person for negligence, default, breach of duty or
breach of trust had been brought.

(3) Where a case to which subsection (1) applies is being tried by a judge with
a jury, the judge, after hearing the evidence, may, if he is satisfied that the
defendant or defender ought in pursuance of that subsection to be relieved
either in whole or in part from the liability sought to be enforced against him,
withdraw the case in whole or in part from the jury and forthwith direct
judgment to be entered for the defendant or defender on such terms as to costs
or otherwise as the judge may think proper."

Item 7. Exemption From Registration Claimed.

Not applicable.

Item 8. Exhibits.

4.1 Memorandum of Association of Acambis plc(1)

4.2 Articles of Association of Acambis plc(2)

5.1 Opinion of Morrison & Foerster MNP

23.1 Consent of Morrison & Foerster MNP (contained in Exhibit 5.1)

23.2 Consent of PricewaterhouseCoopers LLP

24.1 Power of Attorney (see Signature Page)

Item 9. Undertakings.

(a) The undersigned Registrant hereby undertakes:

(1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this Registration Statement to include any material
information with respect to the plan of distribution not previously disclosed in
the Registration Statement or any material change to such information in the
Registration Statement.

(2) That, for the purpose of determining any liability under the Securities Act,
each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.

(3) To remove from registration by means of a post-effective amendment any of
the securities being registered which remain unsold at the termination of the
offering.

(b) The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or 15(d) of the Exchange
Act and, where applicable, each filing of an employee benefit plan's annual
report pursuant to Section 15(d) of the Exchange Act that is incorporated by
reference in this Registration Statement shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

(c) Insofar as indemnification for liabilities arising under the Securities Act
may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
has been advised that in the opinion of the Commission such indemnification is
against public policy as expressed in the Securities Act and is, therefore,
unenforceable. In the event that a claim for indemnification against such
liabilities (other than the payment by the Registrant of the expenses incurred
or paid by a director, officer or controlling person of the Registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.



                                   SIGNATURES

Pursuant to the requirements of the Securities Act, the Registrant, Acambis plc,
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 Cambridge, England, on September 29, 2006.


                                       ACAMBIS PLC


                                       By:      /s/ David Lawrence
                                                David Lawrence
                                                Chief Financial Officer



                               POWER OF ATTORNEY

Each person whose signature appears below constitutes and appoints Gordon
Cameron and David Lawrence, and each of them, as attorneys-in-fact, each with
the power of substitution, for him in any and all capacities, to sign any
amendment to this Registration Statement and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, granting to said attorneys-in-fact, full power and
authority to do and perform each and every act and thing requisite and necessary
to be done in connection therewith, as fully to all intents and purposes as he
might or could do in person, hereby ratifying and confirming the said
attorney-in-fact or his substitute or substitutes, may lawfully do or cause to
be done by virtue hereof.

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

Signature                Title                                Date

/s/ Gordon Cameron       Chief Executive Officer and Director September 29, 2006
Gordon Cameron


/s/ David Lawrence       Chief Financial Officer and Director September 28, 2006
David Lawrence


Alan Smith               Non-Executive Chairman               September __, 2006


/s/ Randal Chase         Non-Executive Director               September 29, 2006
Randal Chase


/s/ Alan Dalby           Non-Executive Director               September 27, 2006
Alan Dalby


Peter Fellner            Non-Executive Director               September __, 2006


/s/ Ross Graham          Non-Executive Director               September 27, 2006
Ross Graham



                               INDEX TO EXHIBITS



Exhibit
Number   Document

   4.1   Memorandum of Association of Acambis plc(3)
   4.2   New Articles of Association of Acambis plc(4)
   5.1   Opinion of Morrison & Foerster MNP
  23.1   Consent of Morrison & Foerster MNP (contained in Exhibit 5.1)
  23.2   Consent of PricewaterhouseCoopers LLP
  24.1   Power of Attorney (see Signature Page)



                                                                     EXHIBIT 5.1

                       OPINION OF MORRISON & FOERSTER MNP

                     (ON MORRISON & FOERSTER MNP LETTERHEAD)


September 29, 2006

Acambis plc
Peterhouse Technology Park
100 Fulbourn Road
Cambridge CB1 9PT
United Kingdom


Re: The Acambis plc 2006 Unapproved Share Option Plan

Dear Sirs

You have requested our opinion with respect to certain matters of English law in
relation to the Registration Statement on Form S-8 (the "Registration
Statement") to be filed by Acambis plc ("Acambis") with the Securities and
Exchange Commission, in connection with the registration under the Securities
Act of 1933, as amended, of up to 2,000,000 ordinary shares of 10p each in
Acambis (the "Shares") offered pursuant to the provisions of Acambis' 2006
Unapproved Share Option Plan (the "Plan"). As your English legal counsel, we
have examined the proceedings taken and are familiar with the proceedings
proposed to be taken in connection with the issue of the Shares.

It is our opinion that, upon completion of the proceedings being taken or to be
taken prior to issue of the Shares, and upon completion of the proceedings being
taken in order to permit such transactions to be carried out in accordance with
the securities laws of the United States and the various states in the United
States and in the United Kingdom, where required, the Shares, when issued in
accordance with the terms of the Plan, will be legally and validly issued, fully
paid and non-assessable.

Our opinions expressed above are limited to the laws of England and Wales and we
do not express any opinion herein concerning any other law.

We consent to the filing of this Opinion as an exhibit to the Registration
Statement.

Yours faithfully

/s/ Morrison & Foerster MNP



                                                                    EXHIBIT 23.2


            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM


We herby consent to the incorporation by reference in this Registration
Statement on Form S-8 of Acambis plc of our report dated 26 June 2006, which
appears in the Annual Report on Form 20-F of Acambis plc for the year ended
December 31, 2005.

/s/ PricewaterhouseCoopers LLP

Cambridge, England
September 29, 2006
--------------------------



(1) Filed as Exhibit 3.1 to the Registrant's Registration Statement on Form F-4,
as filed with the Commission on February 10, 1999 (File No. 333-72077), and
incorporated herein by reference.

(2) Filed as Exhibit 1.2 to the Registrant's Annual Report on Form 20-F for the
year ended December 31, 2004 on June 30, 2005 and incorporated herein by
reference.

(3) Filed as Exhibit 3.1 to the Registrant's Registration Statement on Form F-4,
as filed with the Commission on February 10, 1999 (File No. 333-72077), and
incorporated herein by reference.

(4) Filed as Exhibit 1.2 to the Registrant's Annual Report on Form 20-F for the
year ended December 31, 2004 on June 30, 2005 and incorporated herein by
reference.