can we be infected twice?

In practice, a person already infected with a virus is immunized against it. This is also the principle of vaccination. However, cases of Covid-19 re-contamination have been reported. So, are you really immune after being affected by a coronavirus?

Are we protected after SARS-CoV-2 infection? The re-emergence of cases already infected in South Korea raises fears of a weak immunity after an infection with SARS-CoV-2. So what do we know about the antibody response generated by our body? Overview of the subject in this video with two experts.

When the organism is in contact with a virus, he develops antibody specific able to recognize the virus when faced with it again. It is also the principle of vaccination and progressive immunization, which involves banking on the fact that the majority of the population comes into contact with the virus and is gradually protected, thereby eliminating the disease.

" When 60% of the population has been in contact with the virus, the reproduction rate (number of people infected by a patient), drops to 1 and theepidemic no longer spreads ", Explains the mathematician and epidemiologist Jean-Stéphane Dhersin, to the site 20 minutes. Unless there is a mutation, as is the case with the seasonal flu, it is therefore normally impossible to be infected twice. However, there is still no evidence of mutation of SARS-CoV-2 who can explain for a second wave of contamination.

Coronavirus re-infections: misinterpretation or failure of tests?

However, several media have reported the case of patients who have been re-infected with coronavirus. The Chinese site Caixin indicated, for example, on February 25 that 14% of those recovered from Covid-19 in the city of Guangdong, in the south of the country, had been tested positive again after subsequent tests. In Japan, the government reported the case of a patient who was treated in hospital and tested positive several weeks later.

In reality, it is probably not re-infection, but rather a prolonged infection. The scientific review The Lancet indicates that the viral load can last up to 37 days in the body. Another hypothesis, a failure of the tests: the sensitivity of screening tests PCR (by analysis ARN) would be only 53% to 88%. It is also possible that the samples have been stored incorrectly or that the viral load is insufficient to be detected.

A chinese study conducted on macaques re-infected with the virus SARS-CoV-2 after the disappearance of a first infection is also rather reassuring: none of the monkeys developed symptoms disease or new viral load, " suggesting that a primary infection effectively protects from virus Says the study.

Coronavirus: how long does immunity last?

It remains to be seen how long acquired immunity. According to a study published in 2007 in the journal Emerging Infectious Diseases and dealing with the epidemic of SARS in China in 2003, the antibody levels remains stable for about two years, before dropping drastically in the third year, " suggesting re-infection may be possible after three years Says the study. However, no case of patient already affected by SARS-CoV1 and having fallen ill has been reported. The level of antibodies is in fact not a reliable indicator of the risk of infection, certain people being able to be immunized without the specific antibodies being detected.

The best insurance to protect yourself from the Covid-19 remains developing a vaccine which, unfortunately, is not expected before 18 min minimum. And hoping that SARS-CoV-2 has not mutated by then.

This will also interest you

The post can we be infected twice? appeared first on Smart Be Well.