FORM 4 [ ] Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).         
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES
                                                                                  
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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
                      
1. Name and Address of Reporting Person * Johnston Lloyd P. 2. Issuer Name and Ticker or Trading Symbol SELECTA BIOSCIENCES INC [ SELB ] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable)_____ Director                    _____ 10% Owner
__X__ Officer (give title below)    _____ Other (specify below)
COO and SVP, R&D
(Last)         (First)         (Middle)
C/O SELECTA BIOSCIENCES, INC., 65 GROVE STREET
3. Date of Earliest Transaction (MM/DD/YYYY)
2/11/2021
(Street)
WATERTOWN, MA 02472
(City)       (State)       (Zip)
4. If Amendment, Date Original Filed (MM/DD/YYYY)
 
6. Individual or Joint/Group Filing (Check Applicable Line) _X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Trans. Date 2A. Deemed Execution Date, if any 3. Trans. Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Common Stock  2/11/2021    M(1)    44871  A $0.63  102605  D   

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Trans. Date 3A. Deemed Execution Date, if any 4. Trans. Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
6. Date Exercisable and Expiration Date 7. Title and Amount of Securities Underlying Derivative Security
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option (right to buy)  $0.63  2/11/2021    M        44871    (2) 2/16/2021  Common Stock  44871.0  $0  0  D   

Explanation of Responses:
(1)  The Reporting Person has elected to exercise and hold the shares at this time in advance of the option's expiration.
(2)  All shares underlying this option are fully vested.

Reporting Owners
Reporting Owner Name / Address
Relationships
Director 10% Owner Officer Other
Johnston Lloyd P.
C/O SELECTA BIOSCIENCES, INC.
65 GROVE STREET
WATERTOWN, MA 02472


COO and SVP, R&D

Signatures
/s/ Matthew Bartholomae, Attorney-in-Fact for Lloyd P. Johnston 2/16/2021
**Signature of Reporting Person Date