Can Covid be resumed?

Once healed Covid can be resumed? And how long can theimmunity of people tested positive? From the start of the pandemic to the present, the question has been at the center of numerous studies. To date, what seems evident is that if almost all patients, following the infection, develops antibodies against Sars-CoV-2, these tend to decrease in the following months.

According to the indications of the Ministry of Healthin fact, the vaccine is also recommended for people who have already had the infection, both symptomatically and asymptomatically.

To try to to clarify the issue of re-infection and on the duration of immunity in people who tested positive we asked some questions to Professor Fabrizio Pregliasco, virologist of the University of Milan and Health Director of the IRCCS Galeazzi of Milan.

Professor, the topic of re-infection and the duration of immunity in people who tested positive for Covid-19 is one of the most discussed in science. What do we know today: can Covid be resumed? Can anyone who is healed rely on natural protection and for how long?
«The data is still being consolidated but we can say that at 3 months 1% of subjects, regardless of the severity of the disease, they are re-infecting themselves. This is probably related to different immune responses. However, it is a fact that we expected and that does not surprise us because it is an aspect also typical of other Coronaviruses: they do not give long-term protection, as happens with measles or other diseases that can only be contracted once in a lifetime “.

Is this why those who have recovered from the virus must get vaccinated?
«Yes, there is a risk of re-infection and therefore the desirability of combining recovery from the disease and vaccination, it certainly gives a very high protection. It should also be said that to date we lack the confirmation of the protection evaluation parameters: the antibody titer is certainly indicative but we do not know its cut off. Some colleagues suggested not vaccinating the recovered to aim at vaccinating the others, but more than anything else to implement a wide-ranging strategy ».

Is natural protection more effective than vaccine protection?
“Yes, this applies to all vaccines and all infectious diseases. Protection after infection it is stronger than that given by the vaccine but it must be considered that, in the case of Sars-CoV-2, it is not infinite ».

Why is the serological test not useful to evaluate the levels of antibodies in a person recovered from Covid -9 and to know if he is protected or not?
«Precisely for what we were saying: we do not yet have the cut-off level for this type of test, that is, we do not know the threshold within which we can consider ourselves protected. There are other tests, such as those of neutralization and activation of lymphocytes, which other colleagues are doing but on a small scale because they are very expensive and complex tests ».

Is it possible to say that those who have had Covid in a severe form probably have a higher level of antibodies than those who have contracted the virus in a paucisymptomatic or asymptomatic form?
«No, it is not possible to tell. The severe symptomatic form is linked, so to speak, to a sort of uncoordination of the immune response which then determines that chain reaction of inflammation of the alveoli, viral pneumonia and all that follows. However, this mechanism does not imply that a person cured of this form can be better protected “.

Does the fact that a person has had Covid in a light form exclude the possibility of contracting it in a more severe form in the future?
«Exactly, a more serious re-infection cannot be ruled out. There have been cases of elderly people who died at the second re-infection. Also for this reason the vaccine is always recommended “.

A few days ago the news of the new Omicron variant, also arrived in Italy. What role do variants play on the risk of re-infection in the recovered?
«This is an element still under evaluation. Like that given by the vaccine, natural protection also loses some of its protective capacity compared to a variant. We only know that the natural protection is transversal towards different parts of the virus, so it has a broader spectrum of action, however in relation to a variant, the risk remains even for those who are healed».

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Omicron variant: are anti-Covid vaccines effective? Here’s what we know so far

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