FORM 6-K

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                        Report of Foreign Private Issuer

                    Pursuant to Rule 13s - 16 or 15d - 16 of
                      the Securities Exchange Act of 1934

                           For the month of April 2006


                                  Acambis plc
                (Translation of registrant's name into English)

                           Peterhouse Technology Park
                               100 Fulbourn Road
                               Cambridge CB1 9PT
                                    England

                    (address of principal executive offices)

    (Indicate by check mark whether the registrant files or will file annual
                 reports under cover of Form 20-F or Form 40-F

                         Forms 20-F X     Form 40-F

  Indicate by check mark whether the registrant by furnishing the information
     contained in this Form also thereby furnishing the information to the
                Commission pursuant to Rule 12g3-2(b) under the
                       Securities Exchange Act of 1934).

                              Yes       No X

 (if "Yes" is marked, indicate below the file number assigned to the registrant
                   in connection with Rule 12g3-2(b): 82- ).




Enclosure:

ACAM2000 BLA completed



Acambis completes submission of US licence application for ACAM2000 smallpox
vaccine


Cambridge, UK and Cambridge, Massachusetts - 18 April 2006 - Acambis plc
("Acambis") (LSE: ACM, NASDAQ: ACAM) announces that it has completed submission
of a Biologics License Application (BLA) to the US Food and Drug Administration
(FDA) to seek licensure of its investigational smallpox vaccine, ACAM2000.

As agreed with the FDA, Acambis submitted the BLA on a "rolling" basis, starting
with the first portion in January 2006. The BLA includes safety, tolerability
and immunogenicity data obtained from clinical trials of ACAM2000 conducted in
more than 3,800 subjects. The ACAM2000 programme was given "fast-track" status
by the FDA in December 2004.

Gordon Cameron, Chief Executive Officer of Acambis, commented:

"I'm very proud of Acambis' achievement in completing the ACAM2000 BLA
submission just three-and-a-half years after ACAM2000's Investigational New Drug
application was submitted. We look forward to the FDA completing its
review of the BLA, which we anticipate will come before the end of 2006, based
on ACAM2000's fast-track status."


                                     -ends-


Enquiries:


Acambis plc

Gordon Cameron, Chief Executive Officer

David Lawrence, Chief Financial Officer

Lyndsay Wright, VP, Communications and IR

Tel: +44 (0 1223 275 300

Financial Dynamics

David Yates/Anna Keeble

Tel: +44 (0) 20 7831 3113


About Acambis

Acambis is a leading developer of vaccines to prevent and treat infectious
diseases. Recognised internationally as the leading producer of smallpox
vaccines, Acambis is developing an investigational smallpox vaccine, ACAM2000,
and is manufacturing emergency-use stockpiles of this investigational vaccine
for the US Government and other governments around the world. It is also
developing an attenuated smallpox vaccine, MVA3000, under contracts with the US
National Institutes of Health. Acambis' US-based subsidiary Berna Products
Corporation markets Vivotif(R), the world's only licensed oral typhoid vaccine,
in North America. Acambis' investigational vaccine against Japanese
encephalitis, ChimeriVax-JE, is undergoing Phase 3 clinical testing. It also has
the most advanced investigational vaccine against the West Nile virus, which has
spread to 48 US States in the last six years, and a vaccine against Clostridium
difficile bacteria, a leading cause of hospital-acquired infections.


Acambis is based in Cambridge, UK and Cambridge, Massachusetts, US. Its primary
listing is on the London Stock Exchange (ACM) and its shares are listed in the
form of American Depositary Receipts on NASDAQ (ACAM). More information is
available at www.acambis.com.


"Safe Harbor" statement under the Private Securities Litigation Reform Act of
1995:

The statements in this news release that are not historical facts are
forward-looking statements that involve risks and uncertainties, including the
timing and results of clinical trials, product development, manufacturing and
commercialisation risks, the risks of satisfying the regulatory approval process
in a timely manner, the need for and the availability of additional capital. For
a discussion of these and other risks and uncertainties see "Risk management" in
the Company's 2004 Annual Report and "Risk factors" in its Form 20-F, in
addition to those detailed on the Company's website and in the Company's filings
made with the Securities and Exchange Commission from time to time. These
forward-looking statements are based on estimates and assumptions made by the
management of Acambis and are believed to be reasonable, though are inherently
uncertain and difficult to predict. Actual results or experience could differ
materially from the forward-looking statements.


                                      SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant Peptide Therapeutics Group has duly caused this report to be
signed on its behalf by the undersigned, thereunto duly authorized.



Date: 18 April 2006                          ACAMBIS PLC





                                        By:  /s/ Lyndsay Wright
                                             Name: Lyndsay Wright
                                             Title: VP, Communications and IR.