They are added to re-infections as “suspected cases” of coronavirus: mild patients would produce fewer antibodies

We put under the carpet re-infections of coronavirus. We use whatever arguments we can: 1) “Still unknown“, 2)”still there is almost no re-infected“, 3)”It seems that if you are infected, ready“. The escape serves to revive the difficulty. But come back. Now, the Nation’s Health Department itself has put the issue on the table, with a pdf titled “Recommendations for the management of reinfection and re-exposure to SARS-CoV-2“Something like the” formalization “that re-infections exist.

The text complements the general protocol for managing the pandemic in the country. The new definitions are “suspected case of reinfection“(With its variants” probable “and” confirmed “) and, also,”probable case of viral reactivation“. For now (because the whole stake is in “we’ll see”), the difference between these labels lies in a time saving that some experts are already questioning.

According to Health, if the box restarts within 45 days will be considered suspected of “viral reactivation”. If this happens later, it could be a “reinfection”.

The viral reactivation thing seems new. Who with infinite patience clarified these questions for Bugle he was Jorge quarleri, expert in virology, principal researcher at UBA-Conicet at the Institute for Biomedical Research on Retroviruses and AIDS (INBIRS).

“If you were to watch the PCR virus detection film, assuming that reactivations, we should draw a graph curve with ‘two peaks‘separated by a period of at least 45 days. Each peak would be a PCR detectable by the genome. Sometimes the coronavirus can decrease its replication to very low levels, so it could temporarily go undetected by laboratory methods, ”he explained.

However, the virologist explained, there are a lot of uncertainties and evidence that still need to be investigated before we can give any certainty.

What does health say about the chances of having a second image of the coronavirus? The text assumes that “all over the world” they have reported cases of “RT-PCR positive for SARS-CoV-2, after clinical recovery from an initial episode and the presence of at least two tests. negative for RT -PCR, during the convalescence period ”.

Quote seven cases: two from the United States, one from Hong Kong, one from Belgium, two from India and one from Ecuador. In all, there was a “first” and a “second” time.

Five were symptomatic the first time and two were asymptomatic. In the second round, the asymptomatic patients remained the same; while one of those who had been symptomatic manifested the disease without symptoms, and the others, symptomatic in the first round, suffered from the virus the second time more severely.

How to interpret these sequential episodes? The Health text explains this, or it is a sample that some CRPs give a false negative; o case of proof of viral reactivation; or they are re-infections.

Slippery terrain

Before continuing, some important concepts that we will present in a simplified way, without the endless grays that seem to dominate everything.

There is essentially two main ways of leading to viral reinfection: 1) that after the first infection the organism “fails” and does not generate a robust immune front that allows it to defend itself the next time (or that it generates it, but the armor weakens or, directly , disintegrates), and 2) that the virus reappears “in disguise” and deceives our organism, which Quarleri likes to say using a football metaphor: “As if he wears the jersey of the same team, but with a different number “.

The truth is, the immune system is a complex parallel world. On the one hand, there is the innate immune response, which has no “memory” and is the closest thing to the acidity that the stomach generates to kill microorganisms in food. Then there is the one that matters to us in this pandemic: adaptive immune response, which is separated into two “arms”.

The first is the adaptive humoral immune response, which is in the “humours”, the fluids of the body. “The effectors that exert this immunological action are antibodies, soluble proteins that travel through our fluids. Participants in this process B lymphocytes», Detailed Quarleri.

On the other hand, the T lymphocytes, which mediates the adaptive cellular immune response. “These T lymphocytes then ‘help’ the others, the B lymphocytes, which are involved in the generation of the antibodies,” he added.

If it makes sense to give so many details, it is because the text Health focuses on these responses (humoral and cellular) and displays provisional conclusions based on a fact that seems central: some people develop a good humoral response; others, a good cellular response; others a bit of both … others, a generally good answer, but not lasting. Others, none of the above.

The most disheartening (but central) conclusion of the pdf is that “the concentration of neutralizing antibodies against the virus seem to decrease over time, especially in those who develop infections asymptomatic or mild“.

It is explained that “the extent of the immune response mediated by the B lymphocytes is thought to be related to the severity of the infection; subjects with mild or asymptomatic episodes of first infection lower antibody titers towards those who suffer from a more serious illness ”.

However, again and again, it must be said that everything is in “we’ll see”.

Quarleri was crystal clear: “Our anxiety rates response in months. It must be evaluated over the years. We can speed up certain processes (such as the development of a vaccine), but we cannot ask the same for the immune response: it does its job in each individual according to their timing ”.

So, he stressed, while it is not crazy to assume that “individuals with asymptomatic infections would have a weaker immune response than those who suffer from a more serious illness ”, it must be considered that the number of cases of reinfection “is not enough to generalize the duration of population-wide immunity or the severity of repeated infections ”.

Protocol

It is undeniable that re-infection is a “green” issue, but a protocol had to be worked out in order to guide the staff involved in the treatment of these cases.

How will a person be defined as “suspected case of reinfection“? Salud recommends putting this” tag “on someone who had coronavirus, was cured and got a few negative PCRs, but after 45 days or more, with no clear symptoms, they have a positive PCR again. in addition to the positive test, you present symptoms compatible with Covid, they will be considered as “likely reinfection ”.

And to be labeled as “confirmedThe requirements are not uncommon: a) to have compatible symptoms, b) a positive PCR, and c) laboratory studies which, by comparative genomic analysis of SARS-CoV-2 of the first and second episode, show the presence of different variants, lines or strains of the virus.

Sounds good, but, again, it’s a subject under study. Hardly any scientist (let alone the cautious Quarleri) would go into the fire to claim that reinfections only are generated on contact with a variant of the coronavirus, different from the one that generated the first infection.

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