A Single Dose Vaccine Protection Rate Between 50 and 80 Percent
The Pfizer vaccine, about 3 months after the first injection, guarantees a triple immunological response compared to the 21 days foreseen for the booster. This is what emerges from recent studies on the effectiveness – in the long or short term – of the preventive control of Covid-19 infection. A valid prerequisite for extending the administration times of the second dose by recovering ampoules useful for the vaccination campaign. Or at least, these would seem to be the intentions of General Francesco Paolo Figliuolo in an attempt to bridge the generational gap – still very large – between immunized people over 60 and young people under 40.
Pfizer vials now hold in the refrigerator for a month
Whether there will be a turnaround, it is still too early to tell. The scientific evidence observed so far suggests a high probability that the Pfizer vaccine will ensure valid “coverage” from the virus for 90 days following the first injection. However, to confirm this, it will be necessary to await the definitive outcome of the vaccine immunity studies. In short, the time is not yet ripe to evaluate a change of strategy in the administration of doses. According to Armando Genazzani, Italian member of the CHMP (Committee for medicinal products for human use) of the European regulatory body (EMA) “the government is moving well. – he declares on the pages of Il Messaggero – For now we do not know the effectiveness of vaccines if the times are lengthened, at the moment it is therefore better to do it on schedule. There are some studies, but they are not completed. In a few months, however, we will be able to say with certainty. So, it is better that the people who have taken the first dose complete the vaccination cycle ” .
The risks of the second dose of the Astrazeneca vaccine
The fear related to the possible side effects of the Astrazeneca vaccine is slowing down the timing of the booster (many refuse the second dose after having already done the first) with the risk of a very damaging impasse for the entire vaccination campaign. “For the second dose there does not seem to be an increased risk. – continues Genazzani – At the moment, all the data collected in England indicate that on 10 million second doses the risk is lower than or equal to the first dose. Therefore, people who they took the first dose should complete the vaccination plan without fear “.
“With the 90-day recall, Pfizer protects more”
Recent studies on vaccine immunity show that Pfizer guarantees protection from the virus for 3 months following the first injection. This means that, if the data is confirmed, the recall times could expand from 21 to 90 days. “The studies published by the British and the Israelis – remarked Roberto Giacomelli, director of clinical immunology and rheumatology of the Campus Bio-Medico University Hospital of Rome – show that for patients suffering from severe Covid who require hospitalization even in subjects with a single dose protection rates between 50 and 80 percent. These are obviously data obtained from clinical observation. The decision to postpone the second dose in those countries was political, not scientific “.
Don’t have antibodies after the vaccine… Here’s why and what happens
Now the dilemma also looms. “Unlike England – continues Giacomelli – today we also have some scientific data that comes from the experience of other nations, there are data that say that the protection after the first dose is quite high. .. So one can imagine vaccinating as many people as possible, at least with one dose. Even the hypothesis of administering the second dose using a vaccine other than the first from a biological point of view should not involve any kind of contraindication “.
Before evaluating a possible change of strategy, it will be necessary to wait for the outcome of the clinical observation on the vaccinated. For this reason, Filippo Drago, a member of the Covid task force of the Italian Society of Pharmacology, suggests still adhering to the current EMA directive. “There is a technical data sheet approved by Ema and we must stick to that. The second dose must be performed as indicated. – he says – We cannot go further arbitrarily, we must keep in mind that there is a problem of lack of data available today. Therefore, carrying out the second dose much later could nullify vaccination coverage. Recall that in Great Britain the vaccine used was for the vast majority AstraZeneca. It cannot be compared to Pfizer, which has different times and criteria “…