In Rachana Gangu v Union of India (2026), the Supreme Court directed the Union to formulate a no-fault compensation framework for serious adverse events following COVID-19 vaccination while preserving India's existing AEFI surveillance and causality-assessment architecture. The judgment resolves the question whether compensation machinery is constitutionally required but leaves the central operational question unanswered: what causal connection must an applicant prove to receive compensation? This paper argues that scientific pharmacovigilance causality and legal compensation causality serve different institutional purposes and should not be collapsed into a single test. Drawing on India's 2024 AEFI Guidelines, WHO causality methodology, the United States Vaccine Injury Table and off-table test, Australia's COVID-19 claims scheme, and Asian compensation models, the paper proposes a two-track Indian system. Presumptive 'table injuries' should qualify upon proof of vaccination, specified injury and temporal window, subject to rebuttal by a more probable alternative cause. Off-table injuries should be assessed on a claimant-friendly balance-of-probabilities standard using a structured three-part test. Indeterminate AEFI classifications should not automatically defeat claims. The paper also proposes an independent compensation authority, reasoned decisions, medical assistance for claimants, appeal, transparent publication and preservation of tort and consumer remedies with rules against double recovery.