More than 6 billion doses of coronavirus vaccines have been administered worldwide since the beginning of the year, with over 2.5 billion people completing their vaccination cycles. The vast majority of these individuals will not get COVID-19, and the small fraction of them who develop a post-vaccine infection will have no symptoms and maintain a very low risk of developing severe forms of the disease.
Like all other vaccines, the coronavirus vaccine does not protect 100 percent against the disease, but it makes it extremely unlikely that you will become seriously ill.
The vaccine is in a sense changing COVID-19, at least for those who have undergone the vaccination, making it a different disease from the one that had brought grief and upset our habits in 2020. It is good news, that it must not however lead to underestimate the effects of the virus, which continues to cause the deaths of thousands of people every day around the world, especially where vaccines are not widespread.
Establishing to what extent COVID-19 is changing, between the vaccinated and the rest of the population, is not easy, however, because the disease itself is difficult to define.
Initially, it seemed to cause mostly respiratory problems in the non-immunized, but over the past year and a half doctors and researchers have noticed that depending on the patient, the symptoms vary enormously. The presence of the coronavirus in the body induces a strong immune response, which sometimes gets out of control to the point of damaging tissues in various parts of the body. This reaction is extremely subjective and is what makes it more difficult to determine with certainty the typical symptoms of the disease.
The great subjectivity does not only concern severe cases, but in general the reaction to a coronavirus infection (being infected does not imply that you will then get sick). Many people do not notice that they have been infected because they do not develop symptoms, or they develop very mild ones that can be confused with other health problems or with common illnesses such as a cold or some flu syndrome. Others have more pronounced and recognizable symptoms, which can worsen in a few days, requiring hospitalization. More severe cases must be treated in intensive care, with a greater risk of death.
Coronavirus vaccines have added new variables. Through vaccination, the immune system learns to recognize and deal with the coronavirus, making our body a less hospitable place for the virus, which is therefore blocked and cannot use our cells to replicate. In some cases, a post-vaccine infection can still occur, but from the data collected so far it seems that in these circumstances the virus is eliminated very quickly by the immune system, before it can cause harm and reducing the risk of infecting other people.
The scientific evidence on the protection offered by the vaccine was collected both in the phase of clinical tests, i.e. in the period in which the vaccines were administered to volunteers to verify their safety and efficacy, and after the start of administration in the real world. The checks in the first case were easier to perform, because the researchers could keep some variables under control, while in the second they were and still are more difficult because millions of people live in different places, are made differently and do not have the same habits. of life.
Despite these difficulties, a group of researchers in the UK carried out a search of 4.5 million volunteers, asking them to report the appearance of any symptoms and the results of their tampons via a smartphone app. Of the approximately 1 million participants with completed vaccination courses, only 2,370 (or 0.2 percent) reported testing positive for coronavirus. Only a fraction of these post-vaccine infections led to symptoms, in most cases milder and short-lived than what is seen in COVID-19 patients not immunized with the vaccine.
Other analyzes confirm the efficacy of vaccination and consequently the reduction in risk among vaccinated versus unvaccinated. In Italy, for example, data from the Higher Institute of Health say that in the fully vaccinated population the risk of infection is reduced by 76.9 percent compared to that among the unvaccinated. Vaccines prevent hospitalization in 93.1 percent of cases, hospitalization in intensive care in 95.4 percent and deaths in 95.7 percent.
Analyzes of this type are useful to get an idea of the impact of vaccines, but they inevitably tend to give information on the two opposite extremes of the pandemic: on the one hand, protection against infections in general and on the other, protection against forms severe COVID-19.
As remembers theAtlantic, in doing so we lose the many nuances in the middle, related to vaccinated people who develop moderate or mild symptoms, and which would be very useful to better define how the disease can change in the short to medium term, as the number of immunized increases (of course after the illness, with all the consequent risks, or through the vaccine).
Collecting information on post-vaccine infections is difficult, both because many do not realize they have one, and because those who eventually get sick do not consult a doctor or perform tests to confirm their coronavirus positivity. The data from the medical records of hospitalized patients are more reliable, even if the documentation is not always complete and there are still different ways of registering and following patients in the various countries. Then there is the group of people who continue to have ailments months after the disease, a syndrome often referred to as “long COVID”, whose contours are very blurred, precisely because of the variety of symptoms and the scarce possibility of being followed. by doctors during a pandemic that keeps them busy.
It will still take months to get a more complete picture, but the data collected so far shows how the experience of COVID-19 for individuals is increasingly differentiating between those who are vaccinated and those who are not. Vaccines make contagions less likely, but they can’t stop them completely, which means the coronavirus will continue to circulate. However, it will do so among a population that is increasingly immunized, above all thanks to vaccinations, and therefore with more adequate immune defenses to overcome the infection and possibly the disease.
Various experts believe that we will be continuously exposed to the coronavirus, but that we will be able to count on the protection acquired to prevent the repetition of the scenarios of the first waves in 2020. Continued exposure can also help maintain immune memory, helping us to have the right defenses against any infections. This may be true above all for the population in general, while at the local level and for individual groups of people the path will be less linear, with the possibility of outbreaks.
Much will also depend on the evolution of the coronavirus, as demonstrated by the spread of the delta variant in the West with new increases in infections. However, vaccines have made it possible to significantly reduce their effects, especially as regards hospitalizations and deaths, demonstrating their ability to influence the progress of the pandemic.