In "Without appointment" Monday on Europe 1, Doctor Jimmy Mohamed took stock of what is known about immunization against Covid-19 after a first infection, in response to a question from an auditor .

He also reviewed what the different variants change with regard to this immunization.

DECRYPTION

At the microphone of

 Sans rendez-vous

 Monday on Europe 1, Augustin, an auditor from Metz, says that his doctor certified him that he was immune for two months after having had the Covid-19 last January and that he could even develop antibodies for a longer time.

However, with the appearance of the variants, he wonders if he is really immune.

 Doctor and columnist Jimmy Mohamed answers him by indicating what we know for the moment about immunization after a coronavirus infection and what the variants change.

>> Find all of Sans rendez-vous every day from 3 p.m. to 4 p.m. on Europe 1 as well as in replay and podcast here

How long does immunization take after coronavirus infection?

"What the studies are saying - so this might change over time - is that after infection with the coronavirus, you develop antibodies for at least nine months. That's an average. This means that some patients, especially asymptomatic and older people, may develop antibodies for a little less time. Conversely, some, especially among patients who have been in intensive care and have had severe forms, may produce antibodies longer.

There is therefore no point in playing too much with time.

You need to be vaccinated as soon as possible to get rid of this virus.

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Are there individual variations?

Absolutely.

Individual variations exist.

And again, just because you don't have any more antibodies doesn't mean you're no longer protected ... It's more complicated than that.

In any case, what we know is that children develop twice as many antibodies as adolescents.

The latter develop twice as many as adults.

As we age, our immune system is effectively less efficient.

How does the appearance of variants change regarding immunization?

The appearance of variants redistributes the cards.

With the English variant, it seems that the immunity obtained with the first strain of the virus is rather stable.

On the other hand, the South African and Brazilian variants, which for the moment remain in the minority, representing 5% of PCR tests, confer a slightly more severe infection.

Above all, it escapes an old immunity.

If you caught the coronavirus a month or two ago and you come across these African or Brazilian variants, you will get sick again.

Moreover, sooner or later, there will be variants which will seek to escape the immunity conferred in particular by vaccination.

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How long after infection should you be vaccinated?

First of all, it should be remembered that the immunity conferred by vaccination is much more effective and of longer duration than the immunity conferred by infection.

When you have had the Covid and the disease has been detected by a PCR test or a serological test, you must then wait three months before going to be vaccinated.

The current recommendation says that a single dose is sufficient in this case.

But it is possible that things will evolve when we have a few more vaccines ... For now, it's a dose three months after infection. "