It took only one summer to significantly decrease the antibodies developed against covid by the British population. A large study coordinated by Imperial College London and early Tuesday 27 October before official publication confirms what has long been suspected, namely that immunity to CoViD-19 is probably more similar to the one that mounts in response to other coronaviruses than to the one that develops, once and permanently, against measles.
A notable decline. For the research, commissioned by the British government, 365,000 randomly selected adults were asked to self-administer three times, between 20 June and 28 September, a test for antibodies against SARS-CoV-2, which plans to prick a finger and analyze a drop of blood. The analyzes showed that, within three months, the number of subjects who had antibodies against the new coronavirus dropped by 26.5%.
Extending this data to the whole nation, it is noted that the proportion of people with immunity to covid in the UK has increased from 6% to 4.4%. The decline coincided with the quieter months of the pandemic, when the circulation of the virus, in the UK as in other countries, was more contained thanks to the restrictive measures implemented in the spring.
A more severe covid reinfection than the first
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Faster in asymptomatic patients. The loss of antibodies was slower in people between 18 and 24 years of age than in adults aged 75 and over. The decline was also less pronounced in those who had confirmed the diagnosis of Covid with a classic swab than in those who had contracted the disease without realizing it, in an asymptomatic form. On the other hand, there was no decrease in antibodies in health personnel, continuously exposed to the virus.
Open questions. Uncertainty on the duration of immunity and the small percentage of the population with antibodies underline the importance of adhering to contagion prevention measures such as wearing a mask, respecting physical distance and frequently sanitizing hands. It also remains unclear what kind of protection these antibodies offer and what will be provided from anti-covid vaccineswhen they become available. According to Wendy Barclay, who heads the Department of Infectious Diseases at Imperial College London, in the current state of knowledge “an effective vaccine should offer better protection than simply recovery.”
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