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


SCHEDULE 13G
Under the Securities Exchange Act of 1934



Amendment No.: 1*


Name of Issuer: Achillion Pharmaceuticals, Inc.


Title of Class of Securities: Common Stock


CUSIP Number: 00448Q20-1


Date of Event Which Requires Filing of this Statement: 12/31/2007

Check the appropriate box to designate the rule pursuant to which
this Schedule is filed.

[X] Rule 13d-1(b)
[ ] Rule 13d-1(c)
[ ] Rule 13d-1(d)

* The remainder of this cover page shall be filled out for a
reporting person's initial filing on this form with respect to the
subject class of securities, and
for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall
not be deemed
to be "filed" for the purpose of Section 18 of the Securities
Exchange Act of 1934 ("Act") or otherwise subject to the
liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however,
see the Notes).


CUSIP No.: 00448Q20-1

1.  NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    Janus Capital Management LLC
    EIN #75-3019302

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    a.   ___
    b.   _X_

3.  SEC USE ONLY

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
         Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

   5.    SOLE VOTING POWER
         1,902,628**

   6.    SHARED VOTING POWER
         -0-

   7.    SOLE DISPOSITIVE POWER
         1,902,628**

   8.    SHARED DISPOSITIVE POWER
         -0-

9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
    1,902,628**

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES
    N/A

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
    12.0%**

12. TYPE OF REPORTING PERSON
    IA, HC
    ** See Item 4 of this filing


CUSIP No.:  00448Q20-1

1.  NAME OF REPORTING PERSON
    S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON
    Janus Global Life Sciences
    84-1474315

2.  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    a.   ___
    b.   _X_

3.  SEC USE ONLY

4.  CITIZENSHIP OR PLACE OF ORGANIZATION
         Massachusetts

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:

   5.    SOLE VOTING POWER
         851,950**

   6.    SHARED VOTING POWER
         -0-

   7.    SOLE DISPOSITIVE POWER
         851,950**

   8.    SHARED DISPOSITIVE POWER
         -0-

9.  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
    851,950**

10. CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN
SHARES
    N/A

11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
    5.5%**

12. TYPE OF REPORTING PERSON
    IV

**  See Item 4 of this filing



Item 1.
  (a). Name of Issuer: Achillion Pharmaceuticals, Inc.
("Achillion")

  (b). Address of Issuer's Principal Executive Offices:

       300 George Street
       New Haven, CT 06511

Item 2.
  (a).-(c).  Name, Principal Business Address, and Citizenship of
Persons
             Filing:

       (1)   Janus Capital Management LLC ("Janus Capital")
             151 Detroit Street
             Denver, Colorado  80206
             Citizenship:  Delaware

       (2)   Janus Global Life Sciences
             151 Detroit Street
             Denver, Colorado 80206
             Citizenship:  Massachusetts


  (d). Title of Class of Securities: Common Stock

  (e). CUSIP Number:  00448Q20-1

Item 3.

This statement is filed pursuant to Rule 13d-1 (b) or 13d-2(b) and
the person filing, Janus Capital, is an investment adviser in
accordance with Section 240.13d-1(b)(ii)(E) as well as a parent
holding company/control person in accordance with Section 240.13d-
1(b)(ii)(G).  See Item 4 for additional information.

Janus Global Life Sciences is an Investment Company registered
under Section 8 of the Investment Company Act of 1940.

Item 4. Ownership

The information in items 1 and 5 through 11 on the cover page(s)
on Schedule 13G is hereby incorporated by reference.

Janus Capital has an indirect 86.5% ownership stake in Enhanced
Investment Technologies LLC ("INTECH") and an indirect 30%
ownership stake in Perkins, Wolf, McDonnell and Company, LLC
("Perkins Wolf").  Due to the above ownership structure, holdings
for Janus Capital, Perkins Wolf and INTECH are aggregated for
purposes of this filing. Janus Capital, Perkins Wolf and INTECH
are registered investment advisers, each furnishing investment
advice to various investment companies registered under Section 8
of the Investment Company Act of 1940 and to individual and
institutional clients (collectively referred to herein as "Managed
Portfolios").

As a result of its role as investment adviser or sub-adviser to
the Managed Portfolios, Janus Capital may be deemed to be the
beneficial owner of 1,902,628 shares or 12.0% of the shares
outstanding of Achillion Common Stock held by such Managed
Portfolios.  However, Janus Capital does not have the right to
receive any dividends from, or the proceeds from the sale of, the
securities held in the Managed Portfolios and disclaims any
ownership associated with such rights.

Janus Global Life Sciences is an investment company registered
under the Investment Company Act of 1940 and is one of the Managed
Portfolios to which Janus Capital provides investment advice.

Item 5. Ownership of Five Percent or Less of a Class

Not applicable.

Item 6. Ownership of More than Five Percent on Behalf of Another
Person

The Managed Portfolios, set forth in Item 4 above, have the right
to receive all dividends from, and the proceeds from the sale of,
the securities held in their respective accounts.

The interest of one person, Janus Global Life Sciences, an
investment company registered under the Investment Company Act of
1940, in Achillion Common Stock amounted to 851,950 shares or 5.5%
of the total outstanding Common Stock.

These shares were acquired in the ordinary course of business, and
not with the purpose of changing or influencing control of the
Issuer.

Item 7.  Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on by the Parent Holding
Company

Not applicable.

Item 8.  Identification and Classification of Members of the Group

Not applicable.

Item 9.  Notice of Dissolution of Group

Not applicable.

Item 10. Certification

By signing below I certify that, to the best of my knowledge and
belief, the securities referred to above were acquired in the
ordinary course of business and were not acquired for the purpose
of and do not have the effect of changing or influencing the
control of the issuer of such securities and were not acquired in
connection with or as a participant in any transaction having such
purposes or effect.



SIGNATURES

After reasonable inquiry and to the best of my knowledge and
belief, I certify that the information set forth in this statement
is true, complete and correct.

JANUS CAPITAL MANAGEMENT LLC

By  /s/  David R. Kowalski                       2/14/2008
  David R. Kowalski,                                Date
    Senior Vice President & CCO

JANUS GLOBAL LIFE SCIENCES

By  /s/  David R. Kowalski                       2/14/2008
  David R. Kowalski,                                Date
    Senior Vice President & CCO



EXHIBIT A
JOINT FILING AGREEMENT

In accordance with Rule 13d-1(f) under the Securities Exchange Act
of 1934, the
persons named below agree to the joint filing on behalf of each of
them of a Statement on Schedule 13G (including amendments thereto)
with respect to the Common Stock of Achillion Pharmaceuticals,
Inc. and further agree that this Joint Filing Agreement be
included as an Exhibit to such joint filings.  In evidence
thereof, the undersigned hereby execute this Agreement as of the
14th day of February, 2008.

            JANUS CAPITAL MANAGEMENT LLC

            By  /s/  David R. Kowalski
               David R. Kowalski, Senior Vice President & CCO

            JANUS GLOBAL LIFE SCIENCES

            By  /s/  David R. Kowalski
               David R. Kowalski, Senior Vice President & CCO