Plaintiff Shonna Hunter brought a religious discrimination claim against her former employer Defendant PeaceHealth.
Plaintiff offered the expert testimony of Dr. Michael J. Mina, MD, Ph.D., who opined that PeaceHealth could have accommodated Plaintiff with N95 respirator and “regular testing” in lieu of vaccination.
PeaceHealth filed a motion to strike Mina’s testimony as irrelevant and unreliable under Daubert and Federal Rule of Evidence 702.
Public Health Expert Witness
Dr. Michael J. Mina, MD, Ph.D. is a physician-scientist and public health expert with extensive expertise in vaccine and infectious disease immunology, vaccinology, epidemiology, infectious disease dynamics, and diagnostics.
Discussion by the Court
1. Mina’s testimony is not relevant
Mina opined that PeaceHealth could have accommodated Plaintiff with an N95 respirator and “regular testing” because she would have posed a “markedly lower risk of infecting others” than a vaccinated individual.
On reviewing Mina’s documents, the Court found that Mina made scant cross-reference to scientific or medical sources.
Moreover, with few exceptions, Mina’s sources were not available in August 2021. The undue hardship analysis is confined to the information available to the employer when it made its undue hardship decision.
To the extent that Mina’s opinion is based on scientific or medical sources that were unavailable to PeaceHealth when it made its undue hardship decision in August 2021, the Court held that any part of Mina’s opinion that is not based on scientific or medical data that was available in August 2021 is irrelevant and inadmissible under Daubert and Rule 702.
2. Mina’s testimony is not reliable
a. Mina’s opinion is not supported by the relevant sources
Mina contended that, in August 2021, PeaceHealth knew or should have known that N95 respirators and “regular testing”—not vaccination—”were the best tools available” to stop viral spread.
Mina’s first source, “The Barnstable County Outbreak Report” (“Outbreak Report”), is a CDC report that describes a “significant COVID transmission that occurred during the summer of 2021 in one Massachusetts town related to large public gatherings.” Mina ignored the authors’ warning that “data from this report are insufficient to draw conclusions about the effectiveness of COVID-19 vaccines against SARS-CoV-2, including the Delta variant, during this outbreak.” And the Report nowhere discusses masking and testing or any other mitigation method as an alternative to vaccination. For these reasons, the Court and others have determined that testimony as to vaccine efficacy based on this report is unreliable and have excluded such testimony in prior similar cases.
Mina’s second and third sources are CDC COVID-19 guidance documents from late July 2021: a slide deck (July 29, 2021) and a CDC article (July 30, 2021).
Though the July 29 CDC report (slide deck) included emerging data about breakthrough infections, it also contained data that showed that breakthrough cases were less contagious.
And the July 30 CDC report concluded that Delta “increased the urgency to expand vaccination coverage.” Not one of Mina’s sources recommended N95 respirators and “regular testing” in lieu of vaccination to control COVID-19, even after the appearance of Delta and the increase in breakthrough infections. Instead, masking was recommended only as an adjunct to vaccination. The Court concluded that the three timeframe-relevant CDC sources on which Mina relied did not support his opinion.
b. Mina’s opinion is not supported by the August 2021 scientific consensus
Mina agreed that the August 2021 data showed that vaccines, unlike other mitigation methods, were effective in preventing severe illness and death from SARS-CoV-2. Mina disputed vaccine efficacy only as to transmission. He opined that the “scientific data available to PeaceHealth . . . clearly indicated that N95 masking and regular testing,” not vaccination, “were the best tools available to protect the unvaccinated from becoming infected with and transmitting COVID Delta and later Omicron.”
In August 2021, professional medical and public health organizations and government agencies also recommended vaccine mandates for healthcare workers. Finally, in 2021, when Mina was still a professor at the Harvard School of Public Health, he also appeared to have supported vaccine mandates.
In sum, the August 2021 scientific consensus provided no support for Mina’s opinion that PeaceHealth could have accommodated Plaintiff and hundreds of other employees with N95 respirators and “regular testing” in lieu of vaccination without increasing the health and safety risks to its employees and to its patient population.
Further, Mina failed to address the practical shortcomings of using N95 respirators and “regular testing.” He did not meaningfully address the common-sense observation that respirators do not work if they are not worn properly and continuously and that employees need to remove them to eat or drink and would likely even remove them to ease discomfort—events that could happen repeatedly during a single eight-hour shift.
Held
The Court granted PeaceHealth’s motion to strike Dr. Michael Mina’s testimony.
Key Takeaway
Mina’s opinion is not the product of reliable scientific methodology. An expert must show the court that they have used reliable methodology based on facts and data to reach their conclusions.
“Cherry-picking” facts and data, as Mina has done, undermines principles of the scientific method and is a quintessential example of applying methodologies (valid or otherwise) in an unreliable fashion.
Case Details:
| Case Caption: | Hunter V. Peacehealth |
| Docket Number: | 6:22cv187 |
| Court Name: | United States District Court for the District of Oregon |
| Order Date: | May 31, 2026 |
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