As the new Omicron variant spreads across the United States, vaccinated people who are older or sicker are at greatest risk of hospitalization from a COVID-19 breakthrough infection, according to a new analysis by the Kaiser Family Foundation. Is.
But the shots continue to offer some protection, as these breakthrough diseases tend to be shorter and milder than those of uninsured people, the study found.
“This tells us that older people and those at high risk should be vigilant about COVID, especially given the new version,” said study author and public health expert Cynthia Cox, vice president, Kaiser Family Foundation.
“Even if these are hospitalizations, the vaccine is providing a significant amount of protection for people,” she said.
Much is still unknown as to why some vaccinated people end up with COVID-19 in the hospital. With increasing evidence of reduced immunity and successful infection in fully vaccinated individuals, experts have attempted to answer the question: How well do the shots prevent serious disease and hospitalization?
This new study is the first look at the characteristics of vaccinated people who become very ill – and their hospital experiences, once admitted. Run by the Kaiser Family Foundation and health care software company Epic Systems, it is based on the analysis of electronic medical records of 120,000 patients hospitalized at 250 hospitals in all 50 states between June and September.
Cox said research was done before the detection of the new type of Omicron and before the availability of booster doses, but the clinical course of these “breakthrough” experiences is likely to be similar.
“Older people tend to have weaker immune systems, and the vaccine is not as effective for them as it might be for a younger person,” Cox said.
Public health experts agree that breakthrough infections are relatively uncommon and rarely lead to hospitalization. According to the new study, of all hospital admissions for COVID-19, the vast majority (85%) were people who had not been vaccinated.
But more cases are expected among vaccinated people in the future. Compared to the Delta version, which is still prevalent in the US, Omicron is better at dodging some vaccine-induced immunity. In this study, many people were vaccinated more than six months ago and may have experienced decreased immunity.
The analysis found that more than two-thirds (69%) of success COVID-19 hospitalizations occurred in people 65 years of age and older. A fifth (21%) occurred in people aged 50–64. Only 10% occurred in young adults. In contrast, most of those who were not fully vaccinated and who were hospitalized with COVID-19 were under the age of 64.
Vaccinated adults hospitalized with breakthrough COVID-19 — whether young or old — were more likely to live with chronic health problems such as high blood pressure, diabetes, heart failure or chronic obstructive pulmonary disease.
But these patients were less likely than non-vaccinated people to suffer from the most serious consequences of COVID-19, such as pneumonia or respiratory failure. They were also less likely to require ventilator support or treatment with the anti-inflammatory drug dexamethasone.
And their hospital stay was short. The median stay was 5.6 days for the elderly who were fully vaccinated, compared with 6.7 days for those who were vaccinated or partially vaccinated.
“This suggests that even though these people may be landing in hospital because of COVID, the severity of their illness appears to be low,” Cox said. “So the vaccine is still helping them.”
This is because T cells – a type of white blood cell that play a key role in the human immune system – may have a stronger defense against the virus in vaccinated people. Despite a successful infection, T cells help prevent serious disease.
Since the start of the pandemic, the elderly and the chronically ill have been hardest hit[[[[
“The problem is that most of this (large) population has chronic diseases,” said Los Altos geriatric specialist Dr. Mehrdad Ayati. In December, about 12 to 15 of his patients in skilled nursing facilities have been hospitalized with successful infections. All were vaccinated, and many were amplified.
They are more vulnerable to all pathogens, not just SARS CoV-2 breakthrough infections, he said. “As with any infection, COVID or not, there is a high tendency for them to be hospitalised,” he said.
When the elderly are infected, “other medical problems are magnified,” Ayati said. “For example, if they have heart problems, heart failure tends to appear. If they have diabetes, it’s more likely to go undiagnosed.”
In addition, the elderly are less able to control the virus. During aging, the immune system changes in two major ways. There is a gradual decline in immune function called immunosenescence, which impairs the recognition and clearance of a pathogen. The other change is a greater risk of inflammation called inflammation, which results from an overactive but ineffective alerting system.
He said the study emphasizes the need for the elderly and chronically ill to take extra precautions.
“Even if they do get vaccinated, it means getting a booster shot as soon as possible,” Cox said. “Maybe wearing a mask in public. And to be honest about gathering large groups of people indoors. ,