Miss a day, miss a lot. Subscribe to The Defender's Top News of the Day. It's free.

According to a study published Monday in Nature Cardiovascular Research, COVID-19 and mRNA COVID-19 vaccines are linked to postural orthostatic tachycardia syndrome (POTS), a debilitating autonomic nervous system disorder.

POTS symptoms include an elevated heart rate, dizziness, heart palpitations, fainting, lightheadedness, headaches, chest pain, brain fog, anxiety, depression and fatigue, among others.

Comparing POTS diagnoses 90 days prior to and following vaccine exposure, investigators found that some patients vaccinated against COVID-19 may develop POTS as a response to the shot.

They also found that people diagnosed with COVID-19 are five times more likely to develop POTS after infection than those who developed it after vaccination.

Several research studies previously confirmed POTS as one possible post-COVID-19 syndrome, but this research validates reports of POTS occurring after vaccination as well.

The investigators hypothesized that POTS might be associated with vaccines, given that vaccination elicits an immunological response to the SARS-CoV-2 spike protein. This research affirms that hypothesis.

“We are able to more definitively say that we think that this [post-vaccination POTS] is a real observation,” lead investigator Dr. Alan Kwan told TCTMD.

“It doesn’t quite bring it to the point of being able to tell an individual patient, ‘This is what your specific odds of POTS are after a vaccination,’ but we believe this essentially brings some validity to the observation that POTS may occur after vaccination, though notably at a significantly lower rate than after [COVID-19 itself].”

The researchers analyzed data from 284,592 vaccinated patients and 12,460 patients with COVID-19 from the Cedars-Sinai Health System in Los Angeles County between 2020 and 2022.

The majority of vaccinated people were vaccinated with a Pfizer or Moderna mRNA vaccine. People infected with COVID-19 had not been vaccinated.

Among the vaccinated patients, post-vaccination POTS was diagnosed at a higher rate than other new conditions commonly reported to primary care physicians after vaccination, although there was a stronger association between vaccination and myocarditis.

Among the unvaccinated patients, COVID-19 was associated with greater odds of POTS-associated diagnoses. Notably, rates of POTS diagnosis after COVID-19 infection were higher than those seen after vaccination.

One limitation of the study was that it examined people vaccinated against COVID-19 and unvaccinated people infected with COVID-19, but it excluded people who were vaccinated but also developed the virus.

“In other words, they did not answer the big question,” said Dr. Madhava Setty, senior science editor for The Defender, “which is whether getting vaccinated would reduce your risk of getting POTS (or other ailments) once you contracted COVID-19.”

“Because the vaccine does not prevent infections, and we don’t know if vaccines mitigate the risk of getting POTS after COVID-19, we are left with no idea whether the risk outweighs the benefit,” Setty said.

A growing body of evidence on vaccine side effects

This study adds to the growing body of peer-reviewed evidence demonstrating vaccine side effects, a topic seldom covered in mainstream media, Setty said.

In its coverage of the study linking COVID-19 and mRNA vaccines to POTS, NBC News not only mentioned the vaccine’s connection to POTS, but even included it in the headline — a rarity for a mainstream media outlet, Setty said.

Pharmaceutical company data on vaccine-related adverse events were made public only after a federal judge mandated the U.S. Food and Drug Administration release documents pertaining to Pfizer’s clinical trials.

The vaccine documents show evidence of Pfizer downplaying serious adverse events sustained by participants.

After a series of peer-reviewed studies demonstrating how mRNA vaccines affect the heart, Pfizer and Moderna were compelled to launch clinical trials to track long-term health issues following a diagnosis of vaccine-associated myocarditis and pericarditis in teens and young adults.

Recent research showed that any potential benefits of the COVID-19 booster fail to outweigh the harms associated with vaccine side effects for young people ages 18-29.

The latest data from the Centers for Disease Control and Prevention, released on Dec. 2, showed a total of 595 cases of POTS reported to the Vaccine Adverse Event Reporting System, or VAERS, with 437 cases attributed to Pfizer, 134 cases to Moderna and 23 cases to J&J.

Overall, 1,476,227 reports of adverse events following COVID-19 vaccines were submitted to VAERS between Dec. 14, 2020, and Dec. 2, 2022.

VAERS is the primary government-funded system for reporting adverse vaccine reactions in the U.S.

The data included a total of 32,691 reports of deaths and 268,885 serious injuries, including deaths, during the same time period.

In the U.S., 657 million COVID-19 vaccine doses had been administered as of Dec. 7.