* Member of the American Academy of Microbiology and ** Full Professor of Infectious Diseases, Catholic University, Rome
Although it is difficult, in vaccination matters, to make comparisons between different populations of a genetic, cultural and environmental type, in this article we will try to highlight the different epidemic situations and perspectives of use of the so-called third dose of vaccines against Covid-19 between Israel and Italy. . In this regard, we recall that the idea of a vaccine booster shortly after (a few months) from primary immunization with two doses of vaccine was born, promoted and to a large extent already implemented in Israel.
Third dose Covid vaccine, little evidence of a decline in immunity over time
by Valeria Pini
We took Israeli data from the extensive report (VRBPAC-09.17.21) submitted to the United States Regulatory Body (FDA) a few weeks ago and then summarized in the researchers ‘publication of Maccabi Healthcare Services’ KSM Research and Innovation. They show that the protection conferred by Pfizer-BionTech’s mRNA vaccine against the delta variant of Sars-CoV-2 is significantly reduced starting from the fourth month after the primary immunization course. Specifically, in the age group from 60 years upwards, the protection against hospitalization goes from 97% after 1-2 months to less than 85% at 6 months after vaccination. The protection against infection or mild illness, which does not require hospitalization, falls even further. It is true that the delta variant is very transmissible and capable of evading part of the protective immune response, in short, a distant relative of the ancestral Wuhan viral strain whose mRNA encoding the spike protein was used for vaccination However, there is now a solid consensus that it is not the variant itself that causes the decrease in the effectiveness of the vaccine but the drop in immunity over time. This constitutes a solid rationale for using a new recall. The question is who and when. In Israel, everyone can be vaccinated, that is, from 12 years of age and 5 months from the first two doses.
Covid vaccine, Ema: third modern dose for immunosuppressed over 12
We have already extensively discussed this important aspect when the third dose was already being talked about without supporting data, neither on the safety nor on the efficacy of the booster. We stressed the importance of knowing these data before embarking on a generalized use of the third dose, also, and perhaps above all, due to the inevitable impact on the equity of a wide use of the same in rich countries compared to the still limited availability of effective vaccines in poor countries. We would like to point out here that a protection of around 85% remains a lady protection, which several other commonly used vaccines cannot boast. We also recall that various important researches have shown the presence of a large immune memory after the two doses, supported by populations of B and T cells, capable of reactivating and rapidly forming protective antibodies following a new infection.
Third dose, because some have doubts and prefer to wait
by Giuseppe del Bello
Like various other countries, including Great Britain and the United States, Italy has also decided to promote the use of the third dose of the mRNA vaccine starting with the most vulnerable subjects and health professionals. But what are the data that demonstrate the loss of immunity in the face of the delta variant in our country? In this regard, the ISS reports are useful, in particular the latest published a few days ago, which states that vaccination protection against hospitalization and death from Covid-19 in the general population is substantially maintained at a distance of 6- 7 months from primary immunization. In particular, there is no fall in protection after 7 months in healthcare workers vaccinated with Moderna or Pfizer in January 2021. There is an increase in risk but it seems to be almost entirely borne by immunocompromised, elderly or frail subjects for multiple diseases. – softness.
Vaccines, third dose still in the hubs, then pharmacies and general practitioners
The Italian data are much more similar to those recently published by Pfizer researchers (posted on MedRxiv) on vaccine protection in the follow-up at 6 months from the two doses of the phase 3 trial. They show 92% protection against symptomatic infection and up to 97% against severe disease. This important publication also reports wide differences in protection (from 86 to 100%) depending on the country where the trial was carried out and the ethnicity of the vaccinated subjects.
In conclusion, our data does not seem to justify a collective rush of all vaccinables to the third dose, as in Israel. One of the reasons may be that we have slowly vaccinated two thirds of the population only in late August-early September, while in Israel this large level of immunized population had already been reached in March of this year. The fall of the anti-infectious immunity may therefore be slower and more progressive and the government decision to aim to protect the age group from sixty years upwards in which the risk of serious illness increases, leaving aside for the moment is correct. adolescents and young adult groups who are at lower risk of the disease and potentially greater risk of significant side effects. For this age group there may also be time to evaluate as a booster the use of a vaccine other than Pfizer-BionTech, less reactogenic than those with mRNA, or with a lower vaccine dose, as Moderna has already done with its vaccine. .
Covid, third injection but not for everyone. And halved dosage
by Antonio Cassone * and Roberto Cauda **
It remains a priority to vaccinate those who are not yet even with a dose, which are by no means few, almost 8 (eight!) Million Italians, including almost three over-fifties at risk of serious Covid-19. More generally, we, like all rich countries, should now keep the commitments we have made and quickly provide for primary immunization in poor countries by donating the maximum amount of vaccines we can afford, providing maximum local support for their implementation. It has been said by many but it is good to reiterate it: from that part of the world there may still come a variant that could evade the current vaccines, which and how many doses can be used.
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