COVID for 471 days: Cancer patient had virus evolve three times in body, study finds

A cancer patient with a continuous COVID-19 infection — lasting at least 471 days — had the virus evolve three times in their body, according to a new study led by researchers at Yale.

The findings, which have not been peer-reviewed, suggest that a long-lasting COVID-19 infection may cause the virus to evolve more quickly and allow for infectious new variants, such as delta and omicron, to emerge.

It was estimated that COVID-19 evolved in the cancer patient twice as fast compared with how it does globally on average, according to the scientists.

Here’s what else to know.

The Connecticut cancer patient, who is in their 60’s, was infected with one of the virus’s many lineages — in this case B.1.517 — and it evolved into three different genotypes, according to the work published online as a preprint to MedRxiv on Saturday, July 2. These genotypes could be considered new lineages if they spread beyond the patient.

Study authors noted that the B.1.517 lineage is no longer spreading in the U.S. or anywhere else in the world.

Prior to the research, one potential theory regarding how coronavirus variants emerge suggests that they may come from an immunocompromised person, such as someone with cancer, with a chronic virus infection, according to the study. Such individuals have a higher risk of a longer lasting infection.

“Our findings support the prevailing hypotheses that chronic infections in immunocompromised individuals could be the most likely mechanism driving the unpredictable emergence of genetically diverse SARS-CoV-2 variants,” authors wrote.

The cancer patient’s COVID infection

The cancer patient with lymphoma first tested positive for COVID-19 in November 2020, according to the study. The infection was considered ongoing until at least March and was first identified through genomic surveillance.

In the beginning of their long-running COVID-19 infection, the patient had mild symptoms and did not need hospital treatment, the study said. Afterward, they became asymptomatic.

“Our surveillance system captured 30 nasal swabs from this individual and we sequenced SARS-CoV- 2 genomes from day 79 to 471 (February 2021 to March 2022),” study authors explained.

On day 90, the patient received their only COVID-19 treatment, which was a monoclonal antibody infusion, and chose to not get vaccinated or undergo any other treatments afterward as the infection persisted, the research noted.

This came days after the first of three genotypes, which evolved from the B.1.517 infection, was discovered on day 79, according to the study. Eventually, the second and third genotype “diverged” from the first.

Ultimately, all three genotypes coexisted in the cancer patient’s body simultaneously from day 281 to 471, the scientists found.

“These findings show that this chronic infection resulted in accelerated SARS-CoV-2 evolution and divergence,” which could possibly contribute “to the emergence of genetically diverse SARS-CoV-2 variants, including Omicron, Delta, and Alpha,” the study authors wrote.

“This could be especially problematic as many chronic infections, as was the case with this patient, remain mostly asymptomatic for COVID-19 and may feel well enough to resume regular interactions with other people.”

Authors wrote that one limitation of their study was how a single case was examined and concluded that a better understanding of how the coronavirus may evolve during chronic infections could “curb the evolution and emergence of novel genetically divergent variants.”

While the cancer patient’s infection lasted for at least more than 15 months, the longest recorded COVID-19 case was slightly longer and lasted 505 days before the person died, the BBC reported.

In the U.S., the omicron variant’s subvariants made up all virus cases for the week ending July 2, according to Centers for Disease Control and Prevention data estimates.

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