More than two years after the COVID-19 pandemic, most Americans now have some level of protection against the new coronavirus. Millions have been vaccinated or recovered from a previous infection, producing antibodies that provide varying degrees of immunity.
While this immunity can prevent the most serious infections, it is not infallible and does not always prevent a person from contracting COVID-19 a second time, or even a third or fourth time.
BA.5, a highly contagious omicron subvariant, is now the dominant cause of COVID-19 infections in the U.S., the Centers for Disease Control and Prevention reported.
Although COVID-19 vaccines are now widely available, reinfections have increased in recent weeks. Years after the pandemic, experts said it’s not surprising. Virginia Pitzer, an associate professor of epidemiology at the Yale School of Public Health, said getting infected with COVID-19 more than once will likely become the norm.
“We will live with COVID, reasonably for the rest of our lives, and reinfections will continue to occur,” Pitzer said.
A pharmacist fills a syringe with the Pfizer-BioNTech COVID-19 vaccine (renamed Comirnaty) at a vaccination site in New York’s Bronx neighborhood. (AP)
Who is at risk for COVID-19 reinfections?
All people who were at risk of becoming infected with COVID-19 once are at risk of becoming infected again.
Reinfection and advanced infections after the vaccine are now common, said Marta Galanti, a postdoctoral researcher at Columbia University who has studied coronavirus reinfection since the early days of the COVID-19 pandemic. Vaccination and immunity from previous infection will still protect against serious illness, but that protection diminishes over time, he said.
The risk of reinfection is determined by a person’s level of exposure to the virus and the strength of their immune response, said Dr. Stuart Ray, a professor of medicine in Johns Hopkins ’Division of Infectious Diseases Medicine.
People’s behavior and the rate of COVID-19 transmission to their communities influence their level of exposure to the virus, he said. People’s exposure levels may be higher, for example, if they are regularly in crowded and poorly ventilated areas, or if they are in close contact with someone who has COVID-19 and is at one time more infectious (at principles of its infection). In contrast, a person’s level of exposure could be lower if the COVID-19 transmission rate in their community is low.
The strength of a person’s immune response will vary depending on their health and risk factors and recent COVID-19 infection or vaccination.
What variants of COVID-19 are circulating will also affect a person’s likelihood of reinfection, Pitzer said.
“Your immunity against, for example, a variant that was circulating in late 2020 … will be less protective, especially against the new variant BA.5 that has become dominant in the US and other parts of the world today, which, for example, an infection that occurred a month ago, with a more related virus, ”he said.
As people age, their immune system weakens. Therefore, older people may be more susceptible to reinfections. Immunocompromised people may also face increased risk.
There are COVID-19 antibody tests, but Ray said they are not as informative as people might think.
“I’ve tested my own antibodies and I have some results, but when I ask myself or other experts what those results mean, we don’t know at all,” he said. “We don’t really know what levels of antibodies equate to what degree of immunity.”
A health worker takes a blood sample for a COVID-19 antibody test in Los Angeles on May 20, 2020. (AP)
Ray, who has cared for patients with COVID-19 since the pandemic began, said he has seen innovative infections and reinfections “in just a few months.”
In April, the CDC reported that at least 10 people from four states had tested positive for COVID-19 infection with the omicron variant less than 90 days after testing positive for a previous delta variant infection. These reinfections occurred 23 to 87 days apart, according to the report.
Recently, health officials in Australia recommended reducing the period that someone should be considered immune after testing positive for COVID-19 to 28 days.
How important are reinfections, anyway?
Researchers are looking closely at whether COVID-19, and COVID-19 reinfections, may pose additional health risks.
Although the full picture is still unknown, some research has shed some light on the issue.
People who have recovered from a single case of COVID-19, whether mild, moderate or severe, have a higher risk of cardiovascular and mental health problems in the coming months, according to studies by researchers at Veterans Affairs that relied on a database of veterans’ medical records.
Ray also offered an anecdotal view. “I have cared for a number of people who had COVID a few months ago and are now disqualified from their job because of these types of problems,” he said, listing blood clots, strokes, heart attacks, low blood pressure when standing. , depression and difficulty concentrating as problems.
This is just a single infection.
But a June study, which has not been peer-reviewed but is also based on VA data, found that reinfections pose significant long-term health risks. Although experts said a veterans study might not apply to the general population, Ray said they show people should still be cautious.
“People should think it’s better not to get infected than just get infected and ignore it,” Ray said. “We’re seeing signs that it has a cost.”
How well does my immunity protect me?
Whether people get immunity to COVID-19 from vaccines or previous infections, immunity decreases over time.
The risk of infection increases six months after his most recent vaccine against COVID-19, Pitzer said.
“You’re still protected from the more serious outcomes of a SARS-CoV-2 infection and the more serious disease that goes along with it,” he said. “But you can certainly still get infected or even reinfect yourself with the virus.”
On June 28, 2022, in Miami, Florida, pediatrician Emy Jean-Marie, downtown, holds her nine-month-old son Adedeji Adebayo on her lap while Dr. Nizar Dowla, right, administers a vaccine while the Department of Health and Humanities Undersecretary of Health Services, Admiral Rachel Levine, left, looks. (AP)
It is difficult to compare the longevity of vaccine-induced COVID-19 immunity with immunity from previous infections, Pitzer said. Doing so would require controlling all the factors that contribute to someone becoming infected. And vaccinated people may be more likely to take extra precautions that further reduce their risk of infection, he suggested.
“The real question people have to ask is how do they want to gain their immunity,” Ray said. “Vaccination is much safer than getting infected.”
How do people prevent reinfections?
The same measures that help prevent initial COVID-19 infection also apply to reinfections, according to experts. People who choose to travel or attend large meetings are at increased risk of infection.
“If you have any symptoms that are compatible with COVID-19 infection, even if it’s just a sore throat or a bit of congestion, get tested,” Pitzer said. “If you test positive, make sure you isolate yourself and you’re not spreading it to other people, especially those who might be vulnerable to a more serious outcome.”
During the omicron wave, the CDC has continued to recommend that people be vaccinated, that they wear tight-fitting masks, that they wash their hands regularly, that they maintain the social distance of people who do not live in their homes, that they avoid agglomerations and that tests be performed regularly to prevent the spread of COVID. -19.
Ray also encouraged people to get fully vaccinated, including receiving reinforcements when eligible. He said wearing well-fitting KN94, KN95 or N95 masks can help reduce transmission.
“As a health care provider, I wear a mask all the time in the hospital when I’m caring for people with COVID, and I haven’t had COVID yet,” Ray said. “I think it’s because I wear a mask very carefully.”
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