Some New Jersey residents have become infected with COVID-19 even after receiving a first dose of the two-shot Moderna or Pfizer COVID vaccine, and a tiny number have developed “breakthrough infections” more than two weeks after their second dose of the vaccine.
The total number of such cases in New Jersey is not known, but it appears to be small compared to the 2.6 million people in the state who have been fully vaccinated.
Hackensack Meridian Health has identified 126 such post-vaccine cases, 90% of them among people who had received only the first dose of the Pfizer or Moderna vaccine.
But 10 to 12 of the cases were among people who had completed the second dose of the vaccine at least two weeks earlier and therefore “should have been fully protected,” said Dr. David Perlin, chief scientific officer and head of the health system’s Center for Discovery and Innovation. None of the 126 developed severe illness, although a few were hospitalized, he said.
At St. Joseph’s University Medical Center in Paterson, meanwhile, a medical student became critically ill with COVID-19 almost four weeks after his first dose of the Moderna vaccine and a day or two before he was to receive his second dose, said Dr. Joseph Duffy, the chief medical officer for St. Joseph’s Health. The student, in his 30s, had a confirmed, mild case of COVID last year.
Media reports also described a 52-year-old man in Central Jersey who became critically ill with COVID five weeks after receiving the single-dose Johnson & Johnson vaccine.
The rarity of such “breakthrough infections” is proof of the vaccines’ effectiveness, experts say.
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It also demonstrates the key role in boosting immunity played by the second shot of the two-dose regimens for the Moderna and Pfizer vaccines. Recent research has shown the vaccines to be 80% effective after the first dose, with evidence from clinical trials that protection rose to 94.5% or 95%, respectively, after two doses.
Given the lack of complete protection, “I suspect there is more of this in the community,” Duffy said of COVID infections after vaccination. Most such cases do not come to medical attention, however, because they are mild or the patients have no symptoms.
Vaccines remain the best tool to prevent COVID-19 and end the pandemic, Dr. Anthony Fauci, the nation’s top immunologist, has said. While no vaccine is 100% effective, the three vaccines authorized in the United States had completely prevented hospitalizations and deaths from COVID in clinical trials.
“With any vaccine, we expect such rare cases,” Dr. Rochelle Walensky, director of the federal Centers for Disease Control, said about breakthrough cases of the virus. Of more than 84 million people vaccinated nationwide, the CDC has received reports of 5,814 breakthrough infections in 43 states and territories.
Although the number is likely an undercount, she said, “It still makes a really important point: These vaccines are working.”
Of those patients with reported breakthrough infections, 396 people were hospitalized and 74 died, according to the CDC, although a portion of the hospitalizations and deaths were due to other causes. Nearly 30% had no symptoms at all.
Variants of the virus that causes COVID don’t appear to be to blame for the breakthrough infections. The currently authorized vaccines are working against the variants circulating in the United States, Walensky said.
“Our data would suggest that variants are not driving the infections in these individuals who were vaccinated,” said Perlin, of Hackensack Meridian. The center analyzed virus samples from all 126 cases for variants of the SARS-CoVid-2 virus. Only four were found to have what the federal Centers for Disease Control calls “variants of concern.”
However, their virus samples were collected in the first three months of this year, when variant strains of the SARS-CoVid2 virus were much less common in New Jersey, he said. Now, with variant strains dominant in the virus samples tested at Hackensack’s center,the lab is “vigilant” in its efforts to determine whether any of the breakthrough cases show the variant strains.
Testing for variants a patchwork
But these cases highlight the limitations of current testing and disease reporting as the pandemic evolves and presents new challenges to the health care system.
Testing for variants in New Jersey is a patchwork right now — most hospitals send samples to the state Public Health Laboratory, some send samples to commercial laboratories in New York, and a couple of academic medical institutions — including Hackensack Meridian Health — perform the genomic analysis in-house.
The large laboratories usually aggregate the results so that public health officials have information about which variants are taking hold in the state. Those laboratories seldom have information to indicate whether the sample came from a person who was vaccinated, and don’t provide results to the clinicians treating the patient.
But Perlin, whose center provides results of its in-house analysis to the treating physicians, says information about the variants is relevant for doctors at the bedside.
“When they have a patient who is ill and hospitalized, we want them to know whether they’re dealing with a variant or a run-of-the-mill type” of the virus, he said. Variants containing a particular mutation are “much less sensitive to one of the antibody cocktails. That is a health care issue that obviously impacts the patient.”
Most information about breakthrough cases in New Jersey is anecdotal.
It comes from hospitals and health systems that regularly test their employees for COVID and require patients to be tested for COVID prior to admission or out-patient procedures. The state health department asks doctors and labs to provide specimens for anyone identified as a breakthrough case.
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While the state Health Department has no data on how many cases have occurred, “We are tracking breakthrough cases,” and expect to release numbers in a week or so, said Dr. Ed Lifshitz, director of the department’s communicable disease service.
The department is comparing two databases to determine how many people tested positive after their vaccination. One identifies vaccinated individuals and the other identifies people with positive COVID test results. “The process of pulling data from two systems and matching it is ongoing,” said Donna Leusner, a department spokeswoman.
But even that would not sweep in people who don’t choose to get tested because their infections are so mild they cause few, if any, symptoms.
The CDC is also stepping up its efforts to learn more about breakthrough cases. It announced Friday that it is establishing a database to which each state will be expected to submit data. Agency investigators will focus on cases that result in hospitalization or death.
With the limited data so far, the CDC has reported that such infections occur among patients of all ages. Nearly two-thirds of the breakthrough infections so far were in women. And no pattern was found in terms of the vaccine manufacturer or any underlying conditions of the patients.
Lindy Washburn is a senior health care reporter for NorthJersey.com. To keep up-to-date about how changes in the medical world affect the health of you and your family, please subscribe or activate your digital account today.