The vaccination campaign for third doses, in the population groups authorized so far, is in full swing and provides for the additional inoculation of vaccines designed in the initial stages of the pandemic. However, some scientists wondered if it was not appropriate to “update” the preparations to better correspond to the variants currently in circulation. Objective elements in the hands of experts suggest that sooner or later it will have to happen anyway, although it is not easy to determine when precisely.
Effectiveness preserved even against Delta
«The vaccine and the booster dose are calibrated on the Wuhan stock that no longer exists. Despite this, the vaccine efficacy is not affected and the variants are still covered. Obviously, the problem of a possible formula change was scientifically correct ”, says Massimo Ciccozzi, director of the Medical Statistics and Molecular Epidemiology Unit of the Bio-medical Campus in Rome. Last month there was a yes from the American FDA to extra doses in the original formulation of the Pfizer / BioNTEch vaccine after studies have shown, in fact, that it still works quite well against the Delta, not unlike what supported by regulatory authorities in Europe. This is therefore the reason why it was decided (for the moment) to postpone, despite a decrease in the protection against the Delta variant. The tests for the modern and Johnson & Johnson vaccine boosters are now under evaluation by the FDA.
Scientists from all research centers at work
“The booster dose was perhaps already calibrated on the Indian variant with fast production processes as is characteristic of an mRNA vaccine, thanks to its ductility”. It is clear, according to Ciccozzi, that “a vaccine designed on the Delta variant would increase the efficacy on a viral strain now prevalent all over the world“. Although the preparations in use remain strongly a guarantee against hospitalization and death from Covid, the expectation is to support declining protection against less severe infections and for high-risk populations. For this reason, both Pfizer / BioNTEch and Moderna are testing optimized experimental formulas and it is fresh news that even the Oxford researchers – who developed the AstraZeneca vaccine – are working in the same direction. Scientists say it’s important to learn how the immune system reacts to a slightly different booster in case it eventually becomes necessary.
The ambition to suppress the infection
Scientists at Oxford University who developed the Covid vaccine produced by AstraZeneca would now be working on a new and modified version ad hoc to target the Delta variant of Sars-CoV-2. According to rumors of the British press, the updating of the original vaccine has started. Working on it would be the team of “Dame” Sarah Gilbert (the co-creator of the vaccine was awarded this title) in the British university. A source told the news outlet that the new vaccine was designed with the goal “of having something on the shelf ready.” Cases of the Delta variant are again on the rise across the UK, with the aggravation of a new mutation that is now ‘specially guarded’. According to immunologist Eleanor Riley of the University of Edinburgh, a revision of the original preparation could help to end widespread transmission in the UK. And the third dose plan “would probably have a bigger impact if we were using a Delta specific vaccine.” Oxford researchers, in line with others around the world, have so far chosen a precautionary approach. However, an ad hoc vaccine, Riley points out, would be even more efficient in suppressing the risk of infection at the root.