## Facts

- Boston quarantine rules required emigrants to show evidence of smallpox vaccination to avoid detention or revaccination by port authorities.
- Cunard’s ship surgeon offered vaccination to emigrant passengers and issued certificates accepted by quarantine officials; notices about the practice were posted on the ship.
- Mary E. O’Brien, an emigrant passenger, joined a line of about 200 women waiting to be vaccinated and watched vaccinations being performed on others.
- When O’Brien reached the surgeon, she asserted she had been previously vaccinated, but no vaccination mark was visible.
- The surgeon stated he would vaccinate her again; evidence indicated O’Brien held out her arm, made no objection, submitted to the vaccination, and took a vaccination certificate afterward.
- O’Brien later suffered complications (including blistering and ulceration) and sued Cunard for assault and negligence.
- The trial court directed a verdict for Cunard on both counts; O’Brien sought review by exceptions.

## Issues

1. Whether a jury could find an assault based on vaccination administered without O’Brien’s consent.
2. Whether there was sufficient evidence of negligence by the ship surgeon in performing the vaccination, or by Cunard in connection with the vaccination, to submit the case to a jury.

## Decision

- The Supreme Judicial Court of Massachusetts overruled the plaintiff’s exceptions and affirmed judgment for Cunard.
- The court held the record contained no evidence permitting a finding that the vaccination was against O’Brien’s will; her observable conduct indicated consent as a matter of law.
- The court held there was no evidence of negligent vaccination or other negligence attributable to Cunard sufficient to go to the jury; adverse outcomes alone did not establish negligence.

## Legal Principles

- Consent to physical contact is determined objectively from a person’s words and conduct in context, not from undisclosed intentions.
- If a plaintiff’s outward behavior reasonably indicates consent, the actor is justified in proceeding, even if the plaintiff privately objected.
- Battery/assault requires nonconsensual contact; consent negates the wrongfulness of the contact.
- Negligence in medical treatment requires evidence of a lack of due care or professional skill; injury or complications, without more, do not prove negligence.
- A directed verdict is proper where the evidence would not permit a reasonable jury to find the essential elements of the claim.

## Conclusion

Because O’Brien’s conduct in lining up, presenting her arm, and not objecting reasonably communicated consent to the vaccination, the vaccination could not support an assault claim, and because the record lacked evidence of improper care, the negligence claim also failed; the directed verdict for Cunard was affirmed.


O’Brien v. Cunard S.S. Co., 154 Mass. 272, 28 N.E. 266 (1891)