Infimobius at #SMM4H-HeaRD 2026: Multi-Seed DeBERTa Ensemble for Flu Vaccination and Testing Status Classification

Pradyumn Kejriwal, Suhani Singh Charan, Raksha Sharma, Rudra Murthy


Abstract
This paper describes FluENS (Flu ENsemble System), our submission to the Social Media Mining for Health (SMM4H) 2026 Shared Task 3, which targets fine-grained classification of flu vaccination and flu testing statuses from tweets. FluENS builds on the microsoft/deberta-v2-xlarge pre-trained language model and employs a multi-seed ensemble strategy in which five models, each initialized with a different random seed and trained on the full training set, are aggregated through soft-voting over averaged softmax probabilities. We additionally incorporate balanced class weights to mitigate severe label imbalance and apply a two-stage learning rate schedule that separately controls the encoder and classification head. On the development set, FluENS achieves a macro F1 of 79.64% and micro F1 of 85.56% on the flu vaccination sub-task, and a macro F1 of 96.35% and micro F1 of 97.04% on the flu testing sub-task, substantially outperforming a roberta-base baseline across all metrics.
Anthology ID:
2026.smm4h-1.42
Volume:
Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks
Month:
July
Year:
2026
Address:
San Diego, United States
Editors:
Guillermo Lopez-Garcia, Graciela Gonzalez-Hernandez
Venues:
SMM4H | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
260–263
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.42/
DOI:
Bibkey:
Cite (ACL):
Pradyumn Kejriwal, Suhani Singh Charan, Raksha Sharma, and Rudra Murthy. 2026. Infimobius at #SMM4H-HeaRD 2026: Multi-Seed DeBERTa Ensemble for Flu Vaccination and Testing Status Classification. In Proceedings of the 11th Social Media Mining for Health Research and Applications (SMM4H-HeaRD 2026) Workshop and Shared Tasks, pages 260–263, San Diego, United States. Association for Computational Linguistics.
Cite (Informal):
Infimobius at #SMM4H-HeaRD 2026: Multi-Seed DeBERTa Ensemble for Flu Vaccination and Testing Status Classification (Kejriwal et al., SMM4H 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.smm4h-1.42.pdf