Why COVID-19 Vaccines Might Have Failed For Tens of Millions of Americans

Real-world data offer mixed answers to whether the vaccines really worked for immune compromised patients.

A pharmacist makes an injection of the Moderna Covid-19 vaccine at a pharmacy in Paris, on June, 4, 2021. STEPHANE DE SAKUTIN/AFP via Getty Images

With more than half its population fully vaccinated, the U.S. seems to be near the end of the COVID-19 pandemic. (Not to mention that the U.S. has the two most effective COVID-19 vaccines in the world.) However, herd immunity may not be as close as we thought, as new reports emerge that people on certain immunosuppressive drugs may not have developed an adequate response to vaccines.

According to a CNN report Friday, a 73-year-old woman who was taking a drug to treat inflamed lung blood vessels detected no antibodies against COVID-19 after receiving two doses of the Pfizer vaccine. “Her doctor had been reading recent medical studies suggesting the vaccine might not work well for some people taking medications like hers,” the report says.

That’s not a small group of people. According to a recent study by researchers at the University of Michigan, about 60 million Americans are taking immunosuppressants that could weaken the effect of vaccines.

None of the authorized COVID-19 vaccines was tested in people with immune deficiencies. In fact, vaccine makers specifically excluded these people during clinical trials.

Studies on real-world vaccination data provide mixed answers to whether the vaccines would work for them. One study at Mount Sinai in New York City found that patients on certain medications to treat ulcerative colitis and Crohn’s disease were still able to develop a robust antibody response to mRNA-based vaccines. A separate study at Johns Hopkins University of 650 organ transplant patients found that 46 percent of patients who took immunosuppressants had no antibody response after two doses of Pfizer or Moderna.

“No one really anticipated the vaccine responses would look so bad,” Kathryn Stephenson, an infectious disease specialist and assistant professor at Harvard Medical School, told CNN.

“It’s become such a frequent question, such a point of anxiety for patients,” she added, “that last week we had three different meetings and conferences and seminars all talking about this and trying to figure out strategies about what to tell them.”

For now, Stephenson recommends that patients not test antibody levels after vaccination, because it may not be sufficient to say whether the vaccine actually worked. The FDA and CDC also advise against testing antibody levels.

To get a clearer understanding of how COVID-19 vaccines work in immune-compromised patients, the National Institutes of Health plans to recruit volunteers for targeted studies this summer.

“[We’re] going to have to figure out what do we need to do if we want to adequately protect these people,” said Anthony Fauci, the director of the NIH’s National Institute of Allergy and Infectious Diseases (NIAID), on Friday.

Why COVID-19 Vaccines Might Have Failed For Tens of Millions of Americans