In the weeks that followed, she recovered what appeared to be a complete recovery. She even did another test, which was negative, to participate in a study as one of the first donors of convalescent blood plasma in an attempt to help others.
Six months later, in September, Romoser fell ill again, after a trip to Florida with his father. This second fight was much worse. She lost her sense of taste and smell and suffered persistent headaches and fatigue. She tested positive for COVID again – along with her cat.
Romoser believes it was a clear case of reinfection, rather than some mysterious resurgence of the original sleeping infection. Since the coronavirus, like other viruses, mutates regularly as it multiplies and spreads through the community, a new infection would carry a different genetic fingerprint. But since none of the labs saved their test samples for genetic sequencing, there was no way to confirm their suspicion.
“It would be nice to have evidence,” said Romoser. “I was literally called a liar, because people don’t want to believe that it is possible to be infected again. Why would I lie about being sick? “
While millions of Americans struggle to recover from COVID and millions more struggle for the protection offered by vaccines, US health officials may be neglecting a disturbing subset of survivors: those who are infected more than once. Identifying how common reinfection is among people who have contracted COVID – as well as how quickly they become vulnerable and why – has important implications for our understanding of immunity and the nation’s efforts to develop an effective vaccination program .
Scientists have confirmed that reinfections after the initial disease caused by the SARS-CoV-2 virus are possible, but have so far characterized them as rare. Less than 50 cases have been proven worldwide, according to a global reinfection tracker. Only five have been proven in the United States, including two detected in California in late January.
It seems like a pretty insignificant number. But scientists’ understanding of reinfection has been limited by the limited number of U.S. laboratories that retain COVID test samples or perform genetic sequencing. A KHN analysis of surveillance efforts found that many U.S. states are not rigorously tracking or investigating suspected cases of reinfection.
KHN sent questions on reinfection surveillance to all 50 states and the District of Columbia. Of 24 responses, less than half provided details on suspected or confirmed cases of reinfection. Where officials said they are actively monitoring for reinfection, they found many more potential cases than previously anticipated.
In Washington state, for example, health officials are investigating about 700 cases that meet the criteria for possible reinfection, with three dozen awaiting genetic sequencing and only one confirmed case.
In Colorado, authorities estimate that possible reinfections account for only 0.1% of positive coronavirus cases. But with more than 396,000 cases reported, it means that almost 400 people may have been infected more than once.
In Minnesota, authorities investigated more than 150 suspected cases of reinfection, but lack the genetic material to confirm the diagnosis, a spokesman said.
In Nevada, where the first case of COVID reinfection in the United States was identified last summer, Mark Pandori, director of the state’s public health laboratory, said there was no doubt that the cases were undetected.
“I predict that we are missing out on cases of reinfection,” he said. “They are very difficult to determine, so you need specialized teams to do this job, or a central laboratory.”
These cases are different from the so-called long-distance COVID, in which the original infection triggers debilitating symptoms that last for months and the viral particles can continue to be detected. Reinfection occurs when a person is infected with COVID, eliminates that strain and is infected again with a different strain, raising concerns about sustained immunity against the disease. These reinfections occur regularly with four other coronaviruses that circulate between humans, causing common colds.
“Many patients ask, ‘How long will I have to worry about getting COVID again?’ I literally tell them, ‘You will probably be safe for a few weeks, maybe even a few months, but other than that, it’s not very clear.’ “
– Dr. Edgar Sanchez, infectious disease doctor
The guidelines of the Centers for Disease Control and Prevention call for investigation for possible reinfection when someone has tested positive for COVID at least 90 days after an original infection (or at least 45 days for “highly suspicious” cases). Confirmation of reinfection requires genetic sequencing of paired samples from each episode to tell whether the genomes involved are different.
But the United States lacks the capacity for robust genetic sequencing, the process that identifies the fingerprint of a specific virus so that it can be compared with other strains. Jeff Zients, head of the federal task force COVID, noted at the end of last month that the United States ranks 43rd in the world in genomic sequencing.
To date, only a fraction of the positive coronavirus samples have been sequenced, although Biden’s administration is working to rapidly expand the effort. On February 1, CDC director Dr. Rochelle Walensky told reporters that sequencing has “increased tenfold” in the past few weeks, from 251 sequences in the week of January 10 to 2,238 in the week of January 24. The agency is working with private companies, states and academic labs to increase up to 6,000 sequences per week by mid-February.
Washington State epidemiologist for communicable diseases, Dr. Scott Lindquist, said the authorities have prioritized genetic sequencing at the state laboratory, with plans to begin genotyping 5% of all samples collected. This will allow authorities to analyze these nearly 700 potential reinfections, Lindquist said. Most importantly, the effort will also help signal the presence of significantly mutated forms of the coronavirus, known as variants, that can affect how easily the virus spreads and, perhaps, how sick COVID makes people.
“These two areas, reinfection and variants, can intersect,” he said. “We wanted to be ahead, not behind.”
The spectrum of reinfections complicates one of the central questions of the COVID threat: how long after natural infection or vaccination will people remain immune?
Early studies suggested that immunity would be short-lived, just a few months, while more recent research has found that certain antibodies and memory cells can persist in patients infected with COVID for more than eight months.
“We don’t really know” the marker that would signal immunity, said Dr. Jason Goldman, an infectious disease specialist at the Swedish Medical Center in Seattle. “We don’t have the test you can take to say yes or no, you may be infected.”
Goldman and colleagues confirmed a case of reinfection in a Seattle man last fall and have since identified six or seven likely cases. “This is a much more common scenario than is being recognized,” he said.
The possibility of reinfection means that even patients who have had COVID need to remain vigilant about how to contain reexposure, said Dr. Edgar Sanchez, an infectious disease doctor at Orlando Health in Florida.
“Many patients ask, ‘How long will I have to worry about getting COVID again?'” He said. “I literally tell them, ‘You will probably be safe for a few weeks, maybe even a few months, but other than that, it’s not very clear.'”
The message is similar for society at large, said Dr. Bill Messer, an expert in viral genetics at Oregon Health & Science University in Portland, who has reflected on the cultural psychology of COVID’s response. The evidence suggests that there may not be a clear return to normal.
“The idea that we will end this pandemic by defeating this coronavirus, I don’t think that’s how it will happen,” he said. “I think we are more likely to learn to feel comfortable living with this new virus that is circulating among us.”
Kaiser Health News (KHN) is a national health policy news service. It is an independent editorial program from the Henry J. Kaiser Family Foundation, which is not affiliated with Kaiser Permanente.