How long do the defenses produced by the Covid vaccines last? “In most people, the immune response is lasting, but it gradually decays earlier in fragile subjects, such as RSA hosts, so it seems common sense to administer the third dose to these people”, explains Professor Roberto Bernabei, personal physician. of Pope Francis, former member of the CTS and professor of Internal Medicine and Geriatrics. Although outbreaks are occurring in hospices and among health professionals, school is about to leave and the cold season is upon us, vaccine studies are reassuring. All the researches carried out point to a high efficacy of at least 6 months, even if the Delta variant poses several problems in terms of contagiousness. Israel and Great Britain, two of the countries in the world with the highest number of vaccinated compared to the population, face a strong wave of Covid, but hospitalizations and …
How long do the defenses produced by vaccines against Covid? “In most people there immune response is lasting, but gradually decays first in fragile subjects, like the guests of the RSA, for this reason the administration of the third dose to these people, “explains the professor Roberto Bernabei, personal physician of Pope francesco, former member of the CTS and professor of Internal Medicine and Geriatrics. Although outbreaks are occurring in hospices and among health professionals, school is about to leave and the cold season is upon us, vaccine studies are reassuring. All the searches carried out point to a high effective for at least 6 months, even if the Delta variant poses several problems in terms of contagiousness. Israel and Great Britain, two of the countries in the world with the highest number of vaccinated people compared to the population, face a strong wave of Covid, but hospitalizations and deaths remain under control. The challenge of the new variants is unknown, experts explain.
Green pass mandatory, what happens from October
“The data to date on the antidotes approved so far are consolidating on a protection that goes in the best of cases from 9 to 12 months, obviously decreasing even in later times, however, an overall knowledge is still lacking and it is almost certain that it will be necessary to foresee, according to the future epidemiological trend, booster doses, perhaps a bit like in the flu vaccination, intended for the most fragile people ” , explains the virologist Fabrizio Pregliasco.
Covid, the data of 4 September
It microbiologo Massimo Clementi he has rejected the hypothesis of an immunity for 12 months: “The more likely it is to arrive at nine months with the defenses, the Green pass was extended to 12 months for bureaucratic issues “. The Emilia-Romagna Health Councilor, Raffaele Donini, published the data according to which “after 7 months the efficacy of the vaccine is still high (up to 95% against the risk of death), with a slight decrease in health workers, to 83%, while for RSA guests the immunity remains between 88 and 96% “.
Then came a new study, published on New England Journal of Medicine, which sends alarm signals on the precocity of the loss of protection by mRNA vaccines. Lowering the duration of defenses against Sars-Cov-2 by three months, from nine to six. This research evaluated the incidence of symptomatic infections among Californian health workers fully vaccinated with mRNA vaccines, highlighting how, in the period following the completion of the vaccination and for the following four months (from March to June), the efficacy against the symptomatic disease it remained between 94% and 96% and then dropped to 65,5% in July.
The authors point out that in Great Britain, where the interval between first and second doses was extended to 12 weeks, efficacy was maintained at 88% against symptomatic disease associated with the Delta variant. “As seen in other populations that received the mRNA vaccine at standard emergency authorized intervals (12 days for Pfizer and 28 for Moderna), our data also suggest that the efficacy of the vaccine against mild symptomatic disease that does not require of hospitalization is considerably inferior against the Delta variant and may decrease over time after vaccination, “the authors write.
The debate in Italy on the need to administer the third dose of vaccine. Still under study in our country, the second serum booster was tested in Israel where the numbers recommend administration following the drop in antibodies 9-12 months after the first inoculation. To agree to provide the third dose is also Massimo Andreoni, Professor of infectious diseases at the Tor Vergata University of Rome, who underlined: “Initially it will concern frail, elderly and immunosuppressed people who respond less to vaccination, but we will have to proceed in this direction as early as autumn or winter”.
Per health workers and frail people the call of anti Covid is upon us, we are talking about October, in fact the vaccination facilities scattered throughout the country will not be decommissioned. In this sense Modern has submitted to the EMA the application for conditional marketing approval (Cma) of its vaccine (mRNA-1273) at the dose level of 50 grams. The company underlines this in a note. “Phase 2 of the trial demonstrated that this booster dose induces robust antibody responses against the Delta variant,” said Moderna CEO Stéphane Bancel.
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