Covid vaccines, those who become infected afterwards risk fewer serious forms

Two studies indicate that vaccinations reduce coronavirus duration, severity and viral load. A comparison of the data from the UK and Russia

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None Covid vaccine it may claim to offer 100% protection, but it seems that just not the cases Covid-19 among vaccinated people are few, but also that on average the infection causes milder symptoms and disappear faster. To support it, from the pages of New England Journal of Medicine, are the data of two US studies on almost 4 thousand people: Az Heroes (Arizona Healthcare, Emergency Response and Other Essential Workers Surveillance) e Recover (Research on the epidemiology of Sars-Cov-2 in essential response personnel).

MRI vaccines: fewer cases, less severe

Between December and April, the researchers monitored 3,975 people (health workers, essential service workers, etc.), partly vaccine with mRna vaccines e partly no. In the sample they eventually got sick 156 unvaccinated people, while in the vaccinated group only were recorded 5 infections in people who had completed the cycle of vaccinations e 11 in participants partially vaccinated.

The numbers – the scientists report – once again confirm the statistics of effectiveness of mRna vaccines, which with two administrations offer superior protection to the 90% and with a single dose all’80% .

But the purpose of the two studies goes further. The researchers monitored the people who contracted Covid-19 to assess any differences of viral load, of extent of symptoms and of time disease and infection between vaccinated and unvaccinated. In summary, it appears that the viral load in vaccinated people is inferior of 40% compared to unvaccinated ones (which could suggest, but there are no certainties yet, that it is more difficult to spread the virus).

In the vaccinated participants, moreover, the infection appears less aggressive: the disease has milder symptoms (the risk of developing fever was estimated to be 58% lower than in unvaccinated people, for example) and who persist for less time.

Also there positivity to the virus it disappears faster in vaccinated people: on average a week against the two of the unvaccinated people. The studies, however, do not stop, and thanks to the new funding, US researchers intend both to continue investigating the immunity conferred by vaccines and to evaluate their effectiveness against new variants in coronavirus.

Covid vaccines and variants

Some data on the protection conferred by vaccines on both mRna and adenovirus against variants more aggressive than coronaviruses (in particular the Delta variant, which is preparing to become dominant also in our country) they are already there.

And on the other hand just take a look at the current numbers of infections and deaths to understand that, although the cases are increasing again, the you hesitate are a lot different compared to those of previous waves, at least where the vaccination campaigns have been effective.

In UK, for example, where according to the site Our World in Data almost the 66% of the population received at least one dose of vaccine (for two thirds AstraZeneca, by the way), the number of new cases daily grew clearly in June due to the variations, but the bad results remained on a very low and constant level in time. On the other hand, the situation is a little different Russia, as shown by some graphs of Andrea Palladino, data scientist at Apheris, relaunched on Facebook by biologist Enrico Bucci. In this case I knowabout the 16% of the population received at least one dose of anti-Covid vaccines. And if the daily case curve in June grew with an inclination and a number of cases comparable to that in Britain, the number of cases deaths it is sharply higher.

(Immagine: Our World in Data)

Categories:   Science