Court of Appeal Upholds Dismissal of Claim Against Vaccine Manufacturer In Adam v. Ledesma-Cadhit, 2021 ONCA 828, the appellants brought a claim against pharmaceutical manufacturer GlaxoSmithKline (“GSK”) alleging that the company was responsible for the death of their five-year-old daughter in late 2009. The girl passed away just five days after receiving GSK’s Arepanrix vaccine, which was designed to protect against H1N1 influenza or “swine flu”.The Paediatric Death Review Committee of the Office of the Chief Coroner classified the cause of the girl’s death as “undetermined”, though the investigating coroner found that the most likely cause of death was sudden arrhythmic death syndrome. Trial Decision After a three-week trial, the trial judge dismissed the action against GSK. He concluded that the appellants had not introduced evidence that would demonstrate, on a balance of probabilities, that GSK breached the applicable standard of care or that Arepanrix caused the girl’s death. The appellant advanced five grounds of appeal, which were divided into three main categories: (1) Breach of the Standard of Care, (2) Causation, and (3) Costs. Trial Judge Did Not Err in Finding That GSK Did Not Breach the Standard of Care The first issues relating to standard of care were whether GSK, as manufacturer, had discharged its duty to warn of the risks of the vaccine and whether GSK could rely the appellants’ family doctor who administered the vaccine as a learned intermediary. Brown J.A. reviewed the legal principles governing the duty to warn by manufacturers of medical products summarized by the Supreme Court in Hollis v. Dow Corning Corp., 1995 CanLII 55 (SCC),  4 S.C.R. 634 (“Hollis”), including the learned intermediary rule which presumes that the intermediary physician is fully apprised of the risks of the product. A manufacturer can rely on this rule when the intermediary’s knowledge approximates its own (para 19). Brown J.A. explained that the overarching question to be answered in these cases was whether the manufacturer owed the patient a duty to warn of a specific risk (para 20). In Hollis, the Supreme Court broke this down into two-subquestions: (i) Did the manufacturer have a duty to warn recipients of the medical product directly or could it satisfy its duty by warning a learned intermediary, such as a physician? (ii) If the manufacturer could properly discharge its duty by warning the physician, did it adequately warn the physician of the specific risk in light of its state of knowledge at that time (para 20)?Brown J.A. adapted these questions as follows for the appeal (i) Did the trial judge err by concluding that GSK could satisfy its duty to warn recipients of Arepanrix by warning a learned intermediary physician, in this case appellants’ family doctor? (ii) If GSK could properly discharge its duty by warning the physician, did the trial judge err in concluding that GSK adequately warned the family doctor of the relevant risks of Arepanrix in light of its state of knowledge at that time (para 21)?The trial judge held that GSK could satisfy its duty to warn by informing the family doctor of the risks through a monograph and a product information pamphlet. The appellants argued that the learned intermediary rule did not apply since the girl’s mother independently learned about the vaccine and sought it out herself. Brown J.A. disagreed since a vaccine that could only be obtained and used under the supervision of an expert was “squarely within the ambit of the learned intermediary rule” (para 25). The record supported the trial judge’s findings that GSK had discharged its duty to warn by relying on the family doctor, who prior to administering the vaccine had read the monograph provided by GSK and had informed the appellants of the potential side effects (para 27).Brown J.A. concluded that GSK had also met its duty to warn. The monograph that accompanied the vaccine provide detailed information about possible risks and the appellants did not provide evidence that GSK failed to disclose adverse risks that were known or ought to have been known by them at the time (para 34).The appellants also alleged that the trial judge should have inferred a breach of the standard of care form circumstantial evidence. Given the proximity between the administration of the vaccine and the girl’s death, the appellants argued that GSK should have been called on to explain the girl’s death. Brown J.A. characterized this submission as echoing the “discarded maxim of res ipsa loquitur”, that a plaintiff could establish negligence if (i) the thing that inflicted the damage on the plaintiff was under the sole management and control of the defendant, (ii) the occurrence in issue was such that it would not have happened without negligence, and (iii) there was no evidence as to why or how the occurrence took place (para 51). Brown J.A. stated that the maxim is no longer of any use. In negligence actions circumstantial evidence should be weighed by the trier of fact to determine whether the plaintiff established on a balance of probabilities a case of negligence (para 52). Ultimately, there was no direct or circumstantial evidence from which the trial judge could infer that GSK breached its standard of care (para 53-54). Trial Judge Did Not Err on the Issue of Causation To be successful in a negligence action a plaintiff has to establish that the defendant’s breach of the standard of care caused the injury or death (para 55). However, the trial judge held that there was no evidence that the vaccine was capable of causing death and there was an absence of medical evidence that the vaccine caused or contributed to the girl’s death (para 57). Brown J.A. rejected the appellants’ argument that they had established the vaccine caused the girl’s death because defence experts had testified that they could not rule it out as a possibility. Brown J.A. stated that this submission “ignored the entirety of those experts’ submissions” (para 58). Brown J.A. pointed to the testimony of one expert who, on cross-examination, stated “because we don’t know the cause we can’t exclude anything” and that “anything could be the cause really, but we have no evidence” (para 62). Costs Finally, Brown J.A. upheld the trial judge’s decision to award costs to GSK. There was no basis to interfere with the trial judge’s decision that this was not a case where an unsuccessful party should be awarded costs. Brown J.A. emphasized that the trial judge had determined that this was not a case that “came close to establishing liability” and that there was no evidence to relate the girl’s death to the vaccine. The appellants should have known that it was highly unlikely that they could establish causation (para 70-71).