How risky are the COVID-19 vaccines? A new study by the U.S. Centers for Disease Control and Prevention found that the risk of illness, hospitalization and death following the shots is far lower than the danger from becoming infected with the highly contagious and often deadly virus.
Three health threats have surfaced among some vaccinated people: Blood clots and the Guillain-Barre Syndrome neurologic disorder after the Johnson & Johnson shot, and heart inflammation after the Pfizer or Moderna shots, which use a messenger-RNA technology.
But the CDC analysis found that the risk in adults from the vaccines to be minimal compared to the virus that causes COVID-19, which has infected 35 million Americans and killed more than 614,000.
Federal health authorities briefly paused use of the J & J vaccine in April after reports of rare blood clots, mostly among adult women, a controversial move that some critics say has needlessly hampered the effort to get more people vaccinated. Just over half of all Americans and almost 59 percent of those ages 12 and older who are eligible for at least one of the three authorized vaccines have been fully vaccinated.
Health authorities did not suspend use of the Johnson & Johnson shot after reports of Guillain-Barre Syndrome, a serious condition in which the body’s immune system attacks its nerves. Health authorities also did not suspend use of Pfizer and Moderna shots after heart inflammation reports. Warnings of those potential risks since have been added to all three vaccines.
After 12.6 million doses of the one-shot J & J vaccine were administered through June, the CDC report cited 98 new cases of Guillain-Barre Syndrome within 42 days of receiving the shot. One patient died.
The report cited 38 confirmed cases of blood clotting within 15 days of receiving the J & J vaccine, and four deaths.
The CDC study cited 497 reports of myocarditis, or heart inflammation, and no deaths after 141 million second doses of the two-shot Pfizer and Moderna vaccines had been given to adults through June.
“Based on a comprehensive review of existing data,” the report said, “the benefits of vaccinating all recommended age groups with either … vaccine outweigh the risks for vaccination.”
The report noted that risk of any of the serious side effects varied by age and sex. The overall risk of Guillain-Barre Syndrome was 7.8 per million doses, but was highest — 15.6 per million doses — for men ages 50-64, and lowest for women ages 18-29. The overall blood clot rate was 3 per million doses, but highest among women ages 30-49, at 8.8 per million doses.
The overall risk of heart inflammation in adults following second doses of the Pfizer or Moderna vaccine was 3.5 per million doses, but it was highest among men ages 18-29, at 24.3 per million.
The report did not assess risk in teens — the Pfizer shot is authorized for children as young as 12, while the Moderna and J & J vaccines are recommended for adults 18 and older. The CDC has separately assessed reports of heart inflammation in adolescents and teens after the Pfizer shot, including at least one possible death, but has also concluded they are more at risk from the virus.
Putting that into perspective against the risk of the disease, the report found that for men ages 50-64 getting the J & J vaccine, there is an estimated risk of 14-17 cases of Guillain-Barre Syndrome and 1-2 cases of blood clots, but shots would also prevent 1,800 COVID-19 hospitalizations and 140 deaths, per million doses.
For women ages 30-49 getting the Johnson & Johnson shot, there is an estimated risk of 6-7 cases of Guillain-Barre Syndrome and 8-10 cases of blood clots, but the shots would prevent 900 COVID-19 hospitalizations and 20 deaths, per million doses.
With the Pfizer and Moderna vaccines, for every million second doses among men ages 18-29, there would be an estimated 22-27 cases of heart inflammation, but the shots would prevent 300 hospitalizations and 3 deaths.
The CDC’s Advisory Committee on Immunization Practices has met three times to review reports of dangerous side effects and continues to recommend the shots for those who are eligible. The report noted that “with the delta variant,” of the virus, which is far more contagious, “this is more urgent than ever.”
