The first milestone (coverage at 60% at the end of July) was missed due to the greater aggressiveness of the Delta variant. But it will be difficult to reach the second, 80% of immunized at the end of September
The ministry of health has announced that since yesterday in Italy 50% of the vaccinable population (ie over 12 years of age) has received two doses of the drug and therefore protected from contagion. A good news? Undoubtedly s. Good, though, but not very good since compared to road map drawn in March from Palazzo Chigi we are late; and unfortunately the pace of administration in some age groups is slowing down. This reduces the possibility of reaching the fateful herd immunity which would also protect those who cannot get vaccinated against Covid. To preclude this goal now not only the percentage of immunized population but also the fact that the Delta variant, much more aggressive, requires you to increase this percentage.
The so-called plan Son forecasts for July 20 to reach over 60 million doses administered. Basically achieved goal given that the ministry yesterday it reported over 61,700,000 doses injected. The problem for whom and how many people were administered. The same roadmap, in fact, set for the end of July a first herd immunity with the 60% of the population covered. The goal will be missed for two reasons. The first, it would be necessary to bis-vaccinate a few million Italians within a week (the hypothesis touching the threshold of 70 million doses); the second: with the Delta variant the immunity bar is raised.
This central point. Herd immunity depends on the contagiousness of the virus, the famous R0 index, that is, how many people can infect a sick person. The more aggressive the virus, the greater the share of the population it needs to be vaccinated for neutralize the contagion. During the first wave this index fluctuated between 2 and 3. The Delta variant took it to around 8. Consequently, what percentage of vaccinated people now need to reach to trigger herd immunity? According to the physicist of the University of Trento Roberto Battiston 88%, according to the primary virologist of Pisa Roberto Manichetti 80%.
The aforementioned table Figliuolo provides 80% coverage by mid-September But even in this case, several factors play against it. The vaccination campaign shows some signs of slowing down: this time it is not the doses that are missing but the patients. Many over 80s and over 60s are missing, it is expected that in order to vaccinate all dodgers they will need between five and seven months at these rates. All this despite over half a million doses being administered per day. At this point, even the September target is likely to vanish: by that date it will be necessary to have injected over 96 million vaccines. Roberto Burioni on Twitter has repeatedly mentioned the need to introduce the vaccination obligation. On point for politics remains split: Salvini and Meloni do not want to hear about such a measure and instead launch free messages, all especially aimed at the under 40s; the obligation instead advocated by Enrico Letta. And tomorrow the matter will be discussed in the council of ministers.
July 20, 2021 (change July 20, 2021 | 4:57 pm)