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Learning about breakthrough covid: vaccines deter long covid but breakthrough risks higher for cancer, Alzheimer’s patients

CLEVELAND, Ohio — University Hospitals and Case Western Reserve University School of Medicine are discovering how COVID-19 vaccines and breakthrough infections affect long covid, Alzheimer’s and cancer.

The COVID-19 vaccines do protect against long covid in people with breakthrough infections, suggests a large study led by UH. But breakthrough COVID-19 cases are significantly more likely in cancer and Alzheimer’s patients, according to two new studies from the CWRU School of Medicine.

A “breakthrough infection” is when a fully vaccinated person contracts COVID-19. Long covid is when symptoms carry on for months.

Taken together, the two CWRU studies suggest that it’s important even for vaccinated people to wear masks, social distance and wash hands frequently, said Dr. Pamela Davis, research professor at the CWRU School of Medicine.

“Everybody wants to socialize, including maybe especially people with cognitive impairment, and I think this tells us that caution is still very important,” Davis said.

Here are highlights from each research paper, all based on data from thousands of electronic health reacords.

COVID-19 vaccine protects against long covid

The UH research emphasized the importance of vaccination to ward off the potentially serious consequences of long covid.

People who developed a breakthrough case of COVID-19 despite being vaccinated were at significantly lower risk of developing long covid than the unvaccinated, UH found.

Long covid, also called post-acute sequelae of COVID-19, is common in people recovering from the illness. Up to 70% of recovered patients report fatigue, persistent loss of taste or smell, shortness of breath, cough, headache, pain, and a wide array of serious complications affecting various symptoms, studies have shown.

“Long covid is the new epidemic,” said Dr. Grace McComsey, vice president of research and associate chief scientific officer at UH, who led the study. “What we wanted to answer, in a large, real-world-data setting, is what happens if people have a breakthrough infection after being vaccinated for COVID-19?”

Researchers analyzed electronic medical records from more than 1.5 million adult COVID-19 patients from across the United States, before and after COVID-19 vaccines were available. The data included patient information from UH.

McComsey study

Dr. Grace McComsey, vice president of research and associate chief scientific officer at UH, led a study suggesting that people who developed a breakthrough case of COVID-19 despite being vaccinated were at significantly lower risk of developing long covid than the unvaccinated.

UH researchers looked for long covid symptoms that persisted after the initial infection cleared, and new symptoms that appeared after COVID-19 such as hypertension, diabetes, cancer, heart disease, thyroid disease and mental disorders.

The study also looked for signs of COVID-19-related damage done to the body, McComsey said.

Research results were published recently in Open Forum Infectious Diseases, an official publication of the Infectious Diseases Society of America.

McComsey has another study under way that may help explain why the COVID-19 vaccine seems to offer protection against long covid.

This second UH study, called the NEO-CURE cohort study, is currently enrolling approximately 1,000 patients across Northeast Ohio who have recovered from COVID-19. The study is gathering data from patient questionnaires, and collecting blood samples and other fluids in an effort to determine markers that predict long covid.

In order to join the NEO-CURE cohort study, call 440-762-6843,or email [email protected]

2nd study involving long covid

The UH findings were echoed in a separate study that also looked at long covid and breakthrough infections.

Vaccines lowered the risk of long covid by 15%, and death by 34%, according to a study of more than 13 million American veterans published this week in the journal Nature Medicine.

Long COVID-19 symptoms can affect even fully vaccinated people after mild breakthrough infections, but their risk of serious complications such as lung and blood-clotting disorders is much lower than that of unvaccinated people, the study suggested.

Researchers from Washington University and the VA Saint Louis Health Care System examined information from U.S. Department of Veterans Affairs databases.

CWRU: Breakthrough infection rates in cancer patients

The overall risk of breakthrough COVID-19 infections in vaccinated people with cancer was much greater than for vaccinated people without cancer, research by the CWRU School of Medicine suggests.

Researchers compared breakthrough COVID-19 infections between cancer and non-cancer participants, matching for comorbidities, social determinants of health, age and gender, and other demographics.

“When we started, we had a hypothesis based on two facts,” said Rong Xu, professor of biomedical informatics at the CWRU School of Medicine and coauthor of this study. The facts were that cancer patients are immunocompromised because of their treatment, and that the immunity provided by vaccines decreases over time, said Xu, who was lead author; Davis was co-author.

“We wanted to see,iIn the fully vaccinated patient, how the the vaccine can protect them from COVID-19 infection over time,” Xu said.

Other findings:

* The overall risk of breakthrough COVID-19 infections in vaccinated people with cancer was 13.6%, compared to 4.9% for vaccinated people without cancer.

* The highest risk of breakthrough infections was in people with pancreatic cancer (24.7%), liver cancer (22.8%), lung cancer (20.4%) and colorectal cancer (17.5%).

* Cancers with lower risk of breakthrough infections included thyroid (10.3%), endometrial (11.9%) and breast (11.9%).

The cancer study analyzed electronic health records for more than 636,000 vaccinated patients, including more than 45,000 vaccinated people with cancer.

Patients in the study received COVID-19 vaccinations between December 2020 and November 2021 and had not previously been infected. The control group was made up of vaccinated participants without cancer.

Study coauthors include Dr. David Kaelber, professor at the School of Medicine and chief medical informatics officer at MetroHealth System, and Dr. Nathan Berger, professor of experimental medicine at CWRU School of Medicine.

The CWRU cancer study was published recently in the Journal of the American Medical Association Oncology.

CWRU: Alzheimer’s disease following COVID infection

A separate CWRU School of Medicine study suggests that patients with dementia have a significantly higher rate of breakthrough COVID-19 infections than patients of the same age and risk factors other than dementia, researchers said.

Vaccinated patients with dementia had an overall risk for breakthrough infections ranging from 10.3% for Alzheimer’s disease to 14.3% for Lewy body dementia, significantly higher than the 5.6% in the vaccinated older adults without dementia.

For this second CWRU study, researchers examined how often people diagnosed with various types of dementia developed breakthrough COVID-19 infections.

The CWRU researchers chose to focus on how often people with various types of dementia developed breakthrough infections because older adults with dementia were underrepresented in vaccine clinical trials.

“More than a year ago, we found that even if you controlled for all of the other common variables such as obesity, hypertension and heart disease — patients with dementia had elevated risk for getting COVID-19 in the first place,” said CWRU’s Davis. Xu was lead author and Davis was co-author.

“The dementia patients had something in addition that that made them vulnerable to COVID-19,” Davis said. “So when the vaccines came out, we then thought we should test whether these patients were still more susceptible to breakthrough infections after they’ve been fully vaccinated. And indeed, they were.”

The researchers examined health data from more than 262,847 adults 65 or older vaccinated between December 2020 and August 2021, and who didn’t have the infection before being vaccinated. Of that number, 2,764 people were diagnosed with Alzheimer’s disease; 1,244 with vascular dementia, 259 with Lewy body dementia, 229 with frontotemporal dementia and 4,385 with mild cognitive impairment.

The researchers compared the overall risks of breakthrough infections in vaccinated patients with dementia to those without any cognitive impairment.

The study was recently published in the journal Alzheimer’s & Dementia.