BioNLP at #SMM4H-HeaRD 2026 Task 3 Estimating Flu Vaccine Effectiveness: A Temporal-Aware Fine-Tuning and Similarity-Based Few-Shot Prompting Approach
Year: 2026
Type: conference-paper
Abstract: This paper presents our systems for the SMM4H 2026 shared task on flu-related tweet classification across two subtasks: flu vaccination status and flu test outcome classification.For each subtask, we evaluate two approaches: fine-tuning BERTweet-large with a temporal-aware architecture, cross-validation ensembling, and regularization techniques, and a GPT-4o few-shot prompting system with similarity-based dynamic example retrieval, chain-of-thought reasoning and contrastive label ranking.Fine-tuning proves superior for the flu vaccination subtask (micro-F1: 87.90%), where sufficient and relatively balanced training data is available, while few-shot prompting performs better for the flu test subtask (micro-F1: 95.74%), where limited and heavily imbalanced training data renders fine-tuning less effective.
Author: Irina Patularu
Institution: University of Bucharest
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W7166815229
