MedPage Today  2021.01.21

Extrapolating from the limited data from the Pfizer/BioNTech and Moderna COVID-19 vaccine trials, clinicians say the products’ benefits likely outweigh the risks for people with pulmonary hypertension and other rare diseases.

“The reality is folks with rare diseases will never have enough to do the trials out of the gate,” said Tom Maddox, MD, MSc, of BJC HealthCare and Washington University School of Medicine in St. Louis.

Without hard data, he said, clinicians and researchers can only postulate why COVID vaccines would work differently in people with pulmonary hypertension. “What do we understand about how the disease works? How the infection works? How the vaccine works? Is there anything that can cause the vaccine to worsen the disease? Any side effects?”

“The way mRNA vaccines work, the way pulmonary hypertension works, nothing really occurs to us as problematic,” Maddox said in an interview. “I’m not seeing any reason to believe [vaccination] would be dangerous to folks with pulmonary hypertension, also no reason to believe it wouldn’t be as efficacious.”

In general, the primary safety events tied to COVID vaccination are transient flu-like symptoms; severe allergic reactions have been seen but only rarely.

Accordingly, both Pfizer/BioNTech and Moderna vaccines include known allergy to vaccine components as contraindications — not pulmonary hypertension, according to Justin Ortiz, MD, MS, of the University of Maryland School of Medicine in Baltimore and chair of the vaccines and immunization working group of the American Thoracic Society.

In fact, the CDC includes people with pulmonary hypertension in phase 1c vaccination prioritization given that pulmonary hypertension — encompassing several diseases that together affect an estimated 1% of the global population — is recognized as one of the heart conditions that puts people at increased risk of severe illness from SARS-CoV-2 infection.

In 2020, U.S. center directors reported hospitalization and mortality rates of 30% and 12%, respectively, among 50 COVID-19 patients with one of two forms of pulmonary hypertension, namely pulmonary arterial hypertension (PAH; WHO group 1) and chronic thromboembolic pulmonary hypertension (WHO group 4).

In comparison, the COVID case fatality rate is just 1.7% in the U.S. general population, according to mortality data from Johns Hopkins.

“We absolutely believe that PAH patients are a high-risk group” and “we are recommending vaccination for our patients,” said Peter Leary, MD, PhD, of the University of Washington Medical Center.

Nevertheless, the mRNA vaccine data specific to the pulmonary hypertension population are sparse, if not nonexistent.

For example, Pfizer/BioNTech’s vaccine showed 95% efficacy in preventing COVID-19. The phase III trial enrolled more than 2,900 people with chronic pulmonary disease in the 43,548-person study, according to co-author Stephen Thomas, MD, of SUNY Upstate Medical University in Syracuse.

Yet, no participant had pulmonary hypertension, a Pfizer representative confirmed.

About 5% of participants in Moderna’s 30,000-person trial, which reported 94.1% vaccine efficacy, had significant cardiac disease. Moderna did not clarify how many, if any, pulmonary hypertension patients participated in that trial, though probably no more than a few of those 5%.

“In general, it makes sense for pulmonary hypertension patients to get the vaccine, but they certainly should talk to their physicians,” Maddox cautioned.

“Patients on blood thinning medicines or on medicines that affect their immune system are encouraged to discuss with their healthcare providers before they are vaccinated; however, in my opinion, in the vast majority of situations the benefits of vaccination will greatly outweigh the risks,” said Ortiz.

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