Acquired immunity to infections is strong, but even people cured of Covid need vaccines for extra protection – .

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Acquired immunity to infections is strong, but even people cured of Covid need vaccines for extra protection – .


Israel was way ahead of the rest of the world when it comes to COVID vaccination, so it’s no surprise that the data from this corner of the Mediterranean is getting a lot of excitement – it’s a preview of the to come up.
Indeed, this happened recently when researchers at Maccabi Healthcare Services in Tel Aviv published a preprint (a study that has yet to be reviewed by other experts) suggesting that people infected with COVID were better protected. than people vaccinated against delta reinfection. variant. Sadly, some have figured out that this means getting COVID is a better idea than getting the shot.
First, the possibility that a COVID infection will lead to longer lasting immunity than vaccination is not exaggerated. Infection exposes our immune system to several viral proteins, while the most commonly used COVID vaccines introduce a single antigen: the spike protein. This results in a more directed but also more restricted immune response than after infection.

Although people who have had COVID can be re-infected, naturally acquired immunity continues to evolve over time and antibodies remain detectable for longer than expected. New evidence suggests that immunity after severe and mild infection protects against symptomatic and asymptomatic reinfection.
However, aside from the danger of drawing conclusions from data that other scientists have yet to examine, it’s also crucial to put the data in the right context. While the study draws attention to the power of naturally acquired immunity, it does not take into account the risks of obtaining natural immunity through infection. It also does not cast a shadow over the immunity generated by the vaccine.

In fact, the benefit of vaccination is not even discussed in the study since unvaccinated people with no previous infection were not included for comparison. The low rate of COVID-related hospitalizations among vaccinated participants (eight out of 16,000) would likely be significantly lower than unvaccinated people with no previous infection, but this group was not included in the analyzes.

A common reason for not getting vaccinated is the misconception that expecting natural immunity by choosing infection over vaccination is an option. But the immunity acquired by infection can be very expensive.

Indeed, in addition to the obvious risks of serious illness or death, several recent studies show that healthy people who have recovered from COVID have a significantly increased risk of serious long-term health problems, including myocarditis (inflammation of the heart). heart muscle), blood clots and strokes, compared to those vaccinated. And the most rigorous safety oversight in U.S. history has shown COVID vaccines to be safe and effective.

With increasing cases worldwide and deaths from the delta variant, waiting for infection – and risking long-term health problems, serious illness, and death – to gain immunity against the same infection is also unsuccessful. that dangerous.

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The effective immune boost following the combination of natural immunity and a single subsequent vaccine also raises the question of whether one dose is sufficient for people who have had COVID.

Hybrid immunity
The Israeli prepublication, however, highlights our growing understanding of the potent immunity induced by obtaining the vaccine after receiving COVID – something called hybrid immunity. Several studies show a substantial increase in antibody and T cell responses to the vaccine in people who have previously been infected with COVID.
A recent report from the U.S. Centers for Disease Control and Prevention showed that people who recovered from COVID and were subsequently vaccinated had half the risk of re-infection than unvaccinated people who had previously had COVID. So it’s always worth getting the vaccine, even if you’ve had COVID before.

The effective immune boost following the combination of natural immunity and a single subsequent vaccine also raises the question of whether one dose is sufficient for people who have had COVID. Several studies report that immune responses to a single dose of Pfizer or AstraZeneca vaccine exceed those after two doses in people without a previous infection.

Several countries, such as France, Italy and Germany, therefore now recommend a single dose for people who have already been infected with COVID. And infection without vaccination is recognized as immunity under the current Israeli Green Pass rules.

While directing recalls to people who have not been infected can make the most of limited vaccine stocks, personalized schedules and exemptions from vaccination mandates can be logistically difficult in the midst of a pandemic. Testing for antibodies before vaccination is time-consuming and expensive, and presents practical challenges in identifying those who have or have not had COVID before. These exemptions could slow the rollout of vaccines rather than speed it up.

As unprecedented research efforts provide knowledge on a daily basis about our immune responses to COVID infection and vaccination, we need to critically examine the data as well as all the facts surrounding it. We are a long way from ending the pandemic, and the potential risks of becoming infected are indisputable.

Our priority should be to slow transmission and to immunize those who are not vaccinated and who need it most. To avoid vaccination, waiting for infection and hoping for natural immunity does not make sense.

(This article is syndicated by PTI of The Conversation)

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