A review of death certificates of previously healthy Oregon residents aged 16 to 30 years who died of cardiac or undetermined causes from June 2021 to December 2022 found no link between mRNA COVID-19 vaccination and sudden cardiac death.
For the study, published yesterday in Morbidity and Mortality Weekly Report, Oregon Health Authority researchers examined 1,292 death certificates and immunization data for documentation of COVID-19 mRNA vaccination within 100 days of death. A total of 925 males (72%) and 367 (28%) females in the 16- to 30-year age-group died during the study period.
Healthy Oregonians aged 16 and older became eligible for COVID-19 vaccination on April 19, 2021.
"COVID-19 vaccination has been associated with myocarditis in adolescents and young adults, and concerns have been raised about possible vaccine-related cardiac fatalities in this age group," the researchers wrote. "In April 2021, cases of myocarditis after COVID-19 vaccination, particularly among young male vaccine recipients, were reported to the Vaccine Adverse Event Reporting System."
No certificates list vaccination as cause of death
Among 1,292 identified deaths, COVID-19 was cited as the cause of death on 30 certificates. For 101 others, a cardiac cause of death couldn't be ruled out; of them, immunization data were available for 88, and 3 of them had received an mRNA COVID-19 vaccine dose within 100 days of death.
Of 40 deaths among mRNA COVID-19 vaccine recipients, 3 occurred within100 days of receipt. Two of these deaths were attributed to chronic illnesses, and no cause was listed for one. No certificate listed vaccination as the cause of death.
A total of 17 deaths among males (2%) were attributed to COVID-19. Death certificates cited noncardiac causes or other conditions for 842 (91%). Among the remaining 66 males (7%), a cardiac cause of death could not be excluded. Of these 66, vaccination records were available for 58 (88%), and receipt of at least one mRNA COVID-19 vaccine dose was documented for 24 (41%).
Of the 24 male vaccine recipients, 2 (8%) died within 100 days of vaccination. The cause of the first death was listed as natural 21 days after vaccination. The immediate cause of death was congestive heart failure attributed to high blood pressure; other significant conditions were morbid obesity, type 2 diabetes, and obstructive sleep apnea.
The second decedent had received a vaccine dose 45 days before death, which was categorized as "undetermined natural cause." Toxicology results were negative for alcohol, cannabinoids, methamphetamine, and opiates and positive for aripiprazole, ritalinic acid, and trazodone. Follow-up with the medical examiner couldn't confirm nor exclude a vaccine-associated adverse event as the cause.
These data do not support an association between receipt of mRNA COVID-19 vaccine and sudden cardiac death among previously healthy young persons.
Thirteen of the 367 female deaths (4%) were attributed to COVID-19, and 319 (87%) cited noncardiac causes. Among the remaining 35 female decedents (10%), vaccination records were available for 30 (86%), 16 (53%) of whom had received at least one mRNA COVID-19 vaccine dose.
Only one of these deaths occurred within 100 days of vaccination, at 4 days post-vaccination. The cause of death was listed as natural, and the immediate cause was undetermined, listing chronic respiratory failure with hypoxia attributed to mitral stenosis as a contributing factor.
Risk greater after COVID than after vaccination
"These data do not support an association between receipt of mRNA COVID-19 vaccine and sudden cardiac death among previously healthy young persons," the study authors wrote. "COVID-19 vaccination is recommended for all persons aged ≥6 months to prevent COVID-19 and complications, including death."
"Although the rate was higher during the pandemic year of 2021, myocarditis remained an infrequent cause of death among persons in this age group," they wrote. "Detection of a small difference in mortality rate from myocarditis would require a larger sample size."
The authors noted that electronic health records from 40 US healthcare systems from January 2021 to January 2022 revealed that the risk of cardiac complications was significantly higher after COVID-19 infection than after mRNA COVID-19 vaccination among people aged 5 years and older.
Data from the Centers for Disease Control and Prevention's (CDC's) National Center for Health Statistics show background death rates from cardiac causes in Oregonians aged 15 to 34 years of 2.9 and 4.1 deaths per 100,000 in 2019 and 2021, respectively. During the first 2 years of US COVID-19 vaccine availability, vaccination prevented roughly 18.5 million hospitalizations and 3.2 million deaths, the researchers said.
