People over the age of 65 are re-infected with COVID-19 almost twice as often as young people, Danish researchers have found. Older people are more difficult to tolerate the infection and more often die from it, so the new data must be taken into account in strategies to combat the pandemic, experts say, reports gazeta.ru.
Denmark has a comprehensive testing program in which PCR testing is performed on everyone, regardless of the presence of symptoms. More than 2/3 of the population was tested in 2020.
Specialists from the State Serum Institute in Denmark divided patients into those who tested positive during the first wave of infections, from March to May, and in the second, from September to October. They drew attention to cases of re-infection, because it turns out that people over the age of 65 have only 47 percent protection against re-infection, compared to 80 percent in younger people.
“Our study confirms what others have suggested before us – re-infection is rare in young, healthy people, but older people are at greater risk,” said Dr. Steen Ethelberg, one of the authors of the study, published in Lancet.
Re-infection was previously thought to be extremely rare, but the results are thought-provoking, the study’s authors note.
“It is easy to find information that the first natural infection builds immunity against re-disease,” they wrote. “But only 80% of patients are protected and 47% of the elderly. These are far more alarming figures than in previous studies. “
The new data show the importance of vaccination, including among those who have already had COVID-19, the researchers said.
“The results confirm that in the case of SARS-CoV-2, you do not need to rely on immunity after a natural infection, they say. – The global vaccination program with highly effective vaccines is a more effective solution.”
Older people have a harder time with COVID-19 and are at increased risk of dying from the disease, which is why they need to be protected on the basis of new data.
“Because older people are also more likely to survive a serious illness and more likely to die, our findings clearly show how important it is to implement policies to protect the elderly during a pandemic,” the researchers said. is for people to adhere to measures aimed at ensuring the safety of themselves and those around them, even if they have already had COVID 19. Our findings can also shape policies that focus on mass vaccination strategies and easing of restrictive measures. “
In addition, old age is an additional risk factor for the spread of SARS-CoV-2, a group of researchers from the United States found earlier.
It turned out that overweight older people exhale on average three times more microdroplets than other categories of people.
The concentration of the virus in the exhaled air also depends on the viral load. However, even in the asymptomatic course of the disease, obesity and age contribute to the release of viral particles.
The number of exhaled microdroplets increases as the infection progresses, reaching its highest level one week after infection.
Interestingly, as the infection progresses, the virus particles decrease, reaching a size of one micron at the peak of the disease.
Small particles are more likely to be released during breathing, coughing or talking, the researchers note.
They can also stay in the air longer, travel longer distances and penetrate deeper into the lungs when infected.
“The composition and structure of mucus in the airways depends on a person’s age, diet and lifestyle,” the researchers explained.
Physiological changes affect the mucus, which in turn affects the amount of microdroplets released, including those with viral particles.
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