Vaccination is still needed. A new study from Nature Genetics

We are really tired of this shyness on the subject of vaccination against SARS-CoV-2. The evidence of its usefulness and effectiveness, even during the current phase of the pandemic, is overwhelming; the cost-benefit ratio, for all age groups, is still more than favourable; the vaccines are there, and the bivalents have actually proved to be better than the previous version. And yet, instead of remembering how the Italians, faced with the efficient and disciplined machine of General Figliolo, have been vaccinated by a very large and more than sufficient majority, it has been some time since all we do is encourage the idea that it is not so much necessary to continue to get vaccinated anymorethat vaccines are not indispensable and that, in the end, it is better to restrict vaccination to selected sections of the population invited to accept new doses, leaving the rest of the population alone.

Here we are not interested in discussing those subjects who, prey to the need to first of all satisfy their own cognitive biases and then those of their followers with weak analytical skills, dedicate themselves to combing every ISS data, every published article and every piece of news for building castles of busted numbers and supporting all sorts of vaccine trivia.

Here we would like to understand why, faced with a mountain of data, we still niche in pronouncing a few simple words every day, every day and without ever giving up: western vaccines against SARS-CoV-2, despite the limitations that like every medical extent they have and despite the improvability of the current ones, despite the inevitable side effects and despite the difficulties and defects in distribution and logistics, they should be given to everyone, if necessary continuing to repeat the injection even more than once a yeargiven the demonstrated benefits of fresh booster doses in the presence of new epidemic waves. No more indecision and swinging politicsall prone to chasing the randomly fluctuating public opinion, instead of directing and forming the latter.

Today we still have a new study, published in Nature Genetics, with a design if possible of even greater solidity than the previous oneswhich shows us how vaccines not only work from a clinical point of view, but also from an epidemiological point of view, even against Omicron, lowering the transmission rate.

On these pages we had already recalled data showing how vaccines also decrease the circulation of Omicron, but the latest study has significant advantages, which I want to recall here according to the excellent synthesis made by my friend prof. Alessandro Vitale:
1. is a study done on one ideal population for this purpose, that of prisoners in the USA. Ideal population because these are people regularly swabbed regardless of vaccination status, therefore the number of swabs of unvaccinated and vaccinated was identical;
2. the populations examined have been rendered comparable through a very powerful method called propensity score;
3. the study has valued close contacts of people who became infected in prison, which is ideal for measuring contagiousness;
4. the study was made entirely in the Omicron period.

In the analysis, vaccination, prior infection alone, and vaccination with prior infection were found to reduce the risk of transmission of infection from an index case of 22% (6-36%), 23% (3-39%) and 40% (20–55%), respectively. Booster doses and recent vaccination further reduced infectivity among vaccinated cases. Now, as is known, the greatest risk of transmission is between close contacts; it is therefore evident that vaccination and booster doses have a significant reduction effect of the transmission, although not as total or high as in the initial stages of the pandemic. From this it follows that vaccination must be encouraged among all citizens, without distinctions, ambiguous messages, hesitations, gossip and different flues.

There is no need for ambiguity hidden by respect for the interlocutor, but clarity and simplicitysustained over time and based on the data we have, not on the hypotheses of the builders of castles of numbers and on the affirmations of the more or less academically titled pseudoscientific hustlers.