Study highlights importance of not protecting older people from COVID-19 redemption

Most people who have received COVID-19 are protected from relapse for at least six months, but elderly patients are more likely to relapse, according to a study published in The Lancet.

A large-scale evaluation of transplant rates in Denmark in 2020 confirms that only a small proportion of people (0.65%) returned a twice-advanced positive PCR test. However, while preexisting disease protected people under 65 years of age against relapse, for people aged 65 and over it provided only 47% protection, indicating that they are more prone to COVID -19 capture again.

The authors of the first major study of its kind found no evidence that protection against relapse decreased within six months thereafter.

Their findings highlight the importance of measures to protect the elderly at the time of the pandemic, such as improved social distance and priority for vaccines, even for those who have survived COVID-19. The analysis also suggests that people who have contracted the virus should still be vaccinated, as natural protection cannot be relied upon – especially among the elderly.

As of January 2021, COVID-19 had resulted in more than 100 million cases and more than 2 million deaths worldwide. Recent studies have suggested that immunosuppressants are very rare and that immunosuppression can last at least six months, however, the extent to which COVID-19 uptake provides protection against infectious disease remains to be determined. poorly understood.

Our study confirms what several others have shown: reinterpretation with COVID-19 is rare in younger, healthy people, but older people are at greater risk of recurrence. As older people are also more likely to experience severe symptoms of disease, and sadly dying, our findings make clear the importance of implementing policies to protect older people during their illness. pandemic. Given the involvement, the findings reinforce the importance of people adhering to measures that have been put in place to keep themselves and others safe, even if COVID-19 is already have. Our comments could inform policies aimed at broader vaccination strategies and the reduction of lock-in restrictions. “

Dr Steen Ethelberg, Statens Serum Institut, Denmark

The authors of the new study analyzed data collected as part of Denmark’s national COVID-19 testing strategy, through which more than two-thirds of the population (69%, 4 million people) were tested. in 2020. Free national PCR test – open to anyone, regardless of symptoms – is one of the central pillars of the Danish strategy to control COVID-19, a work that sets it apart from most other countries.

Researchers used this data, spanning the first and second waves in the country, to estimate protection against recurrent infections with the original COVID-19 strain. Ratios of positive and negative test results were measured taking into account differences in age, sex, and duration of infection, and these were used to make estimates of protection against relapse. -fold.

Importantly, the authors note that the timing of their study meant that it was not possible to estimate protection against relapse with COVID-19 modifications, and it is known that some more portable. Further studies are needed to assess how protection against infectious disease may be altered by different types of COVID-19.

Among people who had COVID-19 during the first wave between March and May 2020, only 0.65% (72 / 11,068) were positive again during the second wave from September to December 2020. At 3.3% ( 16,819 / 514,271), the rate of infection was five times higher among people who returned a positive test through the second wave after a previous negative test.

Of those under 65 who had COVID-19 during the first wave, 0.60% (55/9,137) tested positive again during the second wave. The prevalence rate during the second wave among people in this age group who had previously tested negative was 3.60% (14,953 / 420,909). Older people were found to be at greater risk of relapse, with 0.88% (17 / 1,931) of people aged 65 and over who were infected in the first wave re-testing positive in the second wave. Among people 65 or older who had not previously been on COVID-19, 2.0% (1,866 / 93,362) tested positive through the second wave.

Similar results were obtained in another cohort study, in which test data from nearly 2.5 million people were assessed to determine reversal rates throughout epilepsy, not just through the second wave. Only 0.48% (138 / 28,875) of people who were previously positive for COVID-19 relapsed at least three months later, compared with 2.2% (53,991 / 2,405,683) of those who tested negative for COVID-19. first. Protection was estimated at 78.8%. Disease protection was again low among people under the age of 65, with authors estimating 80.5% protection for this group. However, protection against relapse was much lower among people over 65 years, with an estimated protection of just 47%.

Due to the high risk of exposure to the virus, an understatement of health care workers was also conducted. Again, results were similar to the results of the main analysis, with 1.2% (8/658) of those who had COVID-19 during the first wave receiving relapses, compared with 6.2% (934 / 14,946) of those that were negative during the first wave. Protection against relapse was estimated at 81.1%.

Further analysis examining a two- and four-month separation between pandemic waves – increasing the time between the first and second trials of patients to limit the chances of recurrence – also co-results. equivalent (76.7% and 82.8% protection from recurrence, respectively).

Based on results from other studies, the authors did not identify any evidence that protection against infectious disease with COVID-19 declined within six months. As COVID-19 was only identified in December 2019, the period of immune protection provided by infection has not yet been determined.

Dr Daniela Michlmayr, from the Staten Serum Institut, Denmark, said: “In our study, we did not identify anything that indicates that protection against relapse is declining within six months of being exposed to COVID-19 has been shown to provide immunity against relapse lasting up to three years, but ongoing analysis of COVID-19 is needed to understand its long-term effect on patients’ chances of developing a relapse. infected again. ” [1]

The authors acknowledge that there are some limitations in their study. Detailed clinical information is recorded only if patients are admitted to hospital, so it has not been possible to assess the severity of COVID-19 symptoms affecting patients’ immunity against return. Reconstruction may have occurred if viral RNA went for more than three months in some patients, although the authors attempted to account for this by assessing gaps. two to four months between COVID-19 waves. Errors in experiments may have occurred, however, it is believed that the PCR tests used are very accurate, and the authors would expect only about two things wrong per 10,000 test in unprotected persons and about three false negatives for every 100 tests in infected people.

Writing in a related reference, Professors Rosemary J Boyton and Daniel M Altmann, of Imperial College London, UK, said: “Oppose more formal re-issue case reports based on inter-virus virus order data different and forced to redefine to reflect a very rare event, many find the data reported by Hansen ‘s colleagues on protection through natural diseases relatively frightening. There is only 80% protection from relapse in general, reducing to 47% in people age 65 and older who are more concerned about figures than previous studies have offered.

They continue, “All of this data provides evidence that, if required, for SARS-CoV-2 the prospect of immune protection against natural diseases may not be within our reach and is a global immunization program with vaccines. high efficiency the permanent solution. “