Company: IMRX
Filing Date: 2025-04-21
Form Type: DEFA14A
Source: 0001790340-25-000055
Chunk: 0

Company: Immuneering Corp
Filing Date: 2025-04-21
Form: DEFA14A
Chunk 0
---
### UNITED STATES

### SECURITIES AND EXCHANGE COMMISSION

#### Washington, D.C. 20549
<div align='center'>___________________________</div>

#### SCHEDULE 14A

#### Proxy Statement Pursuant to Section 14(a) of the

#### Securities Exchange Act of 1934
<div align='center'>(Amendment No. )

___________________________</div>

| Filed by the Registrant |     | x |     | Filed by a party other than the Registrant |     | o |

Check the appropriate box:

| o |     | Preliminary Proxy Statement                                                     |
| o |     | Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) |
| o |     | Definitive Proxy Statement                                                      |
| x |     | Definitive Additional Materials                                                 |
| o |     | Soliciting Material Pursuant to §240.14a-12                                     |

| Immuneering Corporation                          |
| (Name of Registrant as Specified in its Charter) |

| (Name of Person(s) Filing Proxy Statement, if Other Than the Registrant) |

Payment of Filing Fee (Check all boxes that apply):

| x |     | No fee required                                                                                     |
| o |     | Fee paid previously with preliminary materials                                                      |
| o |     | Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11 |