A former pitching prospect in the Major League Baseball (MLB) system has filed a lawsuit against the Chicago White Sox, alleging that a team-imposed COVID-19 vaccination requirement in 2021 caused a debilitating medical condition that prematurely ended his baseball career.
Isaiah Carranza, who played in the club’s minor league system, claims he was coerced into receiving the vaccine under threat of career stagnation and blacklisting. The lawsuit, filed in September 2025 and amended in December, names both the White Sox and MLB as defendants.
Carranza alleges team officials warned that refusing vaccination would result in him being effectively trapped in the minor leagues with no opportunity for advancement, jeopardising his professional future.
According to the complaint, those threats compelled him to receive the first dose of the Pfizer-BioNTech COVID-19 Vaccine in 2021.
He claims that shortly afterward he experienced severe symptoms, including dizziness, nausea, near-fainting episodes, and dramatic fluctuations in heart rate.
Carranza says he was later diagnosed with Postural Orthostatic Tachycardia Syndrome (POTS), a disorder affecting the autonomic nervous system that causes a rapid increase in heart rate upon standing and can significantly impair daily functioning.
His attorneys argue the condition constitutes a career-ending injury for a professional athlete. They also allege the defendants violated the Americans with Disabilities Act by failing to accommodate his condition and downplaying his symptoms.
Attorney John M. Liston, one of Carranza’s co-counsel, argued that the mandate applied to minor league players but not major league players, creating what he described as unequal treatment.
Major league players are unionised under the Major League Baseball Players Association, while minor leaguers historically have fewer workplace protections, a distinction the lawsuit highlights.
The complaint estimates Carranza’s future medical expenses could exceed $557,000, with lost career earnings ranging from $3.4 million to $19.9 million.
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He is seeking compensatory and punitive damages, legal costs, and a court order requiring the defendants to cease alleged discriminatory practices.
The White Sox declined to comment on the case, citing ongoing litigation, while MLB did not immediately respond to requests for comment.
Carranza’s legal team said cardiologist Peter McCullough diagnosed him with vaccine-induced POTS, citing abnormal test results and the timing of symptom onset.
However, the lawsuit states that team representatives suggested stress — rather than vaccination — could have contributed to his condition, an explanation his attorneys strongly dispute.
The case may face complex legal challenges under the Public Readiness and Emergency Preparedness Act (PREP Act), which grants liability protections to manufacturers, administrators, and, in many cases, employers involved in vaccine distribution during public health emergencies.
Individuals claiming vaccine injury typically must seek compensation through the Countermeasures Injury Compensation Program (CICP), administered by the Health Resources and Services Administration.
Critics of the program say it has strict eligibility criteria and long processing times. As of early 2026, thousands of claims had been filed, with only a small fraction deemed eligible for compensation.
Carranza’s lawsuit comes amid continuing debate in the United States over vaccine mandates, workplace requirements, and compensation mechanisms for alleged adverse effects.
Public opinion surveys cited by advocacy groups suggest strong support for personal choice in medical decisions, though public health authorities maintain that COVID-19 vaccines have played a critical role in reducing severe illness and deaths globally.
Carranza’s attorneys say the case raises broader questions about the responsibilities of institutions that impose medical requirements on employees with limited bargaining power.
They expressed hope the lawsuit would help ensure that “everyone has their rights respected and safe access to healthcare.”