The European regulatory agency evaluates the available data despite “not considering reinforcement urgent for all”. The third dose for frail people is also being examined, on whose necessity the opinions are more in agreement
The European Medicines Agency (EMA) has begun evaluating an application for the use of a dose of recall of Pfizer vaccine «To be administered 6 months after the second dose to persons aged 16 or over ». This was announced by the same EU regulatory body, underlining that “separately” it is also “evaluating the literature data on the use of a third additional dose of an mRNA vaccine (Moderna and / or Pfizer) in severely immunocompromised people”.
“Not urgent for everyone”
“The outcome of this assessment is expected within the next few weeks”, specified the regulatory body which continued: “while the EMA evaluates the data” on the recall, “the Member States can already consider preparatory plans for the administration of boosters additional doses “and recalled that,” although Ema do not consider the need for booster doses urgent of the Covid-19 vaccine in the general population, the application of the Pfizer manufacturer is being evaluated “to ensure that evidence is available to support additional doses if necessary.”
The unknowns about the third dose
The debate among experts on the third dose is open: while with regard to frail or immunocompromised people there are more favorable opinions (and medical evidence), regarding the use of the third dose for the entire population and the indicated time frame (6 months), the same World Health Organization (WHO) reiterated that “There is currently no scientific evidence” to show the need for it, especially given that in a large part of the world the vaccination campaign has yet to “start”.
There are two major unknowns: vaccination efficacy does it really drop so that you have to resort to reinforcement? After how many months would it be necessary to do it?
The opinions of the experts
“The third dose, for which scientific evidence demonstrates a stimulating effect (booster effect) on” memory “lymphocytes, it is certainly needed as soon as possible for the immunosuppressed – declared Franco Locatelli, coordinator of the technical-scientific committee, hematologist of the Infant Jesus -. Once the vaccination campaign still in progress has been completed, it will be possible, based on the evidence on the duration of the protection conferred by the vaccination that will become available, to evaluate if and when to give the third dose also to people with particular frailties or very exposed to the risk of infection for professional reasons “.
«We don’t know how long vaccine protection lasts, given that the follow-up of vaccinated people is still too short – said Gianni Rezza, Director General of Prevention at the Ministry of Health, in an intervention published in the Courier service -. However, it seems that, even if the neutralizing antibodies tend to decrease over time, the cellular responses and the memory of the encounter with the viral antigen persist. longer than previously thought».
The decline in effectiveness and the months of protection
Regarding the decline in vaccination efficacy, given that the figure depends very much on the percentage of the population vaccinated in the individual countries, but also on the measures adopted (such as green passes, closures, etc.), the data are uneven but similar in indicating a descent involving transmission capacity (contagions that resume), but not protection against hospitalizations and deaths which remains solid. For this reason it seems premature to indicate a “reinforcement” for the whole population.
To measure the real loss of protection, in fact, we need studies on antibodies and controlled populations. It has been done in some countries on health care and there has been a slight decline, in fact, after about six months in some studies (not in all). Even these studies do not give a certain answer, why immunity given by vaccines it involves not only antibodies (which rise immediately after inoculation and fall a few months later), but also the T and C cells of the immune system, who have memory of the type of virus to “attack” and intervene months or years after the vaccine and there are still few tests done on these, also because few months have passed since the first mass vaccination.
Science needs time, political decision-makers must prepare and intervene with other times, relying on the advice of the scientific committees that examine the data available at that moment which, however, can change at a later time.
September 6, 2021 (change September 6, 2021 | 19:14)
© Time.News