Exhibit 99.1

Vigil Neuroscience Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Business Update

– Reported positive interim data from Phase 2 IGNITE proof-of-concept clinical trial evaluating iluzanebart (VGL101) for treatment of ALSP;

- Enrollment for IGNITE trial completed with 20 patients enrolled; Next data readout planned for Q3 2024 –

– Phase 1 healthy volunteer clinical trial evaluating VG-3927 ongoing; Interim data analysis on track for mid-2024 –

– Appointed Biotech Industry Executive Petra Kaufmann, M.D., M.S., F.A.A.N, as Chief Medical Officer –

WATERTOWN, Mass., March 26, 2024 (GLOBE NEWSWIRE) — Vigil Neuroscience, Inc. (Nasdaq: VIGL), a clinical-stage biotechnology company committed to harnessing the power of microglia for the treatment of neurodegenerative diseases, today announced financial results for the fourth quarter and full year ended December 31, 2023, and provided an update on recent progress.

“Among our many recent milestones, the most significant for Vigil was the positive data readout from our ongoing Phase 2 IGNITE trial and ILLUMINATE natural history study. Findings from these studies have provided critical insights and a rich dataset on biomarkers that we believe support our strategy to advance iluzanebart through clinical development as quickly as possible. We are also pleased to have enrolled 20 patients in our IGNITE trial, exceeding our target of 15 patients. This is a true testament to the importance of our mission to bring a novel therapy to ALSP patients,” said Ivana Magovčević-Liebisch, Ph.D., J.D., President and Chief Executive Officer of Vigil. “Our Phase 1 clinical trial evaluating VG-3927 in healthy volunteers is progressing as planned and we are on track to provide an interim data readout in mid-2024. As the first and only clinical-stage small molecule TREM2 agonist, bringing our next-generation candidate into the clinic is a landmark achievement for the Company and for the Alzheimer’s disease treatment landscape. We look forward to further progressing our two TREM2 modalities through clinical development in 2024.”

Recent Highlights and Anticipated Milestones

Iluzanebart, Monoclonal Antibody TREM2 Agonist

VG-3927, Oral Small Molecule TREM2 Agonist

Corporate

Fourth Quarter 2023 Financial Results

About Vigil Neuroscience

Vigil Neuroscience is a clinical-stage biotechnology company focused on developing treatments for both rare and common neurodegenerative diseases by restoring the vigilance of microglia, the sentinel immune cells of the brain. Vigil is utilizing the tools of modern neuroscience drug development across multiple therapeutic modalities in its efforts to develop precision-based therapies to improve the lives of patients and their families. Iluzanebart, Vigil’s lead clinical candidate, is a fully human monoclonal antibody agonist targeting human triggering receptor expressed on myeloid cells 2 (TREM2) in people with adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP), a rare and fatal neurodegenerative disease. Vigil is also developing VG-3927, a novel small molecule TREM2 agonist, to treat common neurodegenerative diseases associated with microglial dysfunction, with an initial focus on Alzheimer’s disease (AD) in genetically defined subpopulations.

Forward-Looking Statements

This press release includes certain disclosures that contain “forward-looking statements” of Vigil Neuroscience (“Vigil” or the “Company”) that are made pursuant to the safe harbor provisions of the federal securities laws, including, without limitation, express or implied statements regarding: the Company’s strategy, business plans and focus; the progress and timing of the clinical development of Vigil’s programs, including the availability of, and expected timing for reporting, data from both the IGNITE Phase 2 clinical trial and the VG-3927 Phase 1 clinical trial; beliefs about observations made analyzing preclinical study and clinical trial data to date; the anticipated impact of the VG-3927 partial clinical hold on the Company’s clinical development plans and beliefs about the maximum exposure limit, regulatory

progress and clinical progress for VG-3927; the success and timing of the Company’s interactions with regulatory authorities; and the expectation that the Company’s cash runway will be sufficient into the second half of 2025. Forward-looking statements are based on Vigil’s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties related to uncertainties inherent in the development of product candidates, including the conduct of research activities and the conduct of clinical trials; uncertainties as to the availability and timing of results and data from clinical trials; whether results from prior preclinical studies and clinical trials will be predictive of the results of subsequent preclinical studies and clinical trials; the timing and content of additional regulatory information from the FDA; the Company’s ability to work with the FDA to successfully remove the partial clinical hold on VG-3927; whether Vigil’s cash resources will be sufficient to fund its foreseeable and unforeseeable operating expenses and capital expenditure requirements; as well as the risks and uncertainties identified in the Company’s filings with the Securities and Exchange Commission (SEC), including Vigil’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2023, its upcoming Annual Report on Form 10-K for the year ended December 31, 2023 and any subsequent filings Vigil makes with the SEC. Forward-looking statements contained in this announcement are made as of this date, and Vigil undertakes no duty to update such information except as required under applicable law. Readers should not rely upon the information on this page as current or accurate after its publication date.

Internet Posting of Information

Vigil Neuroscience routinely posts information that may be important to investors in the ‘Investors’ section of its website at https://www.vigilneuro.com. The company encourages investors and potential investors to consult our website regularly for important information about Vigil Neuroscience.

VIGIL NEUROSCIENCE, INC.

Consolidated Statements of Operations

(in thousands, except share and per share data)

(unaudited)

VIGIL NEUROSCIENCE, INC.

Selected Balance Sheet Data

(in thousands)

(unaudited)

Investor Contact:

Leah Gibson

Vice President, Investor Relations & Corporate Communications

Vigil Neuroscience, Inc.

lgibson@vigilneuro.com

Media Contact:

Megan McGrath

MacDougall Advisors

mmcgrath@macdougall.bio