Vaibhav Upadhyay and Krishna Mallelatwo scientists from the University of Colorado who have studied the spike protein of the coronavirus since the outbreak of the pandemic, affirmed that the large number of inoculations in process is due to the constant emergence of variants. Most of the differences between the variants are changes in the spike protein, which sits on the surface of the virus and helps it enter and infect cells.reported to the media Medical Press.
As the professionals explain, the modifications in the spike protein allow the coronavirus to infect the human cell in a faster and more efficient way, resulting in earlier vaccines achieving less protection over time.
Different types of vaccines
But it also depends on the classification of the vaccines, which manage to immunize the world population in different ways: Vaccines against COVID-19 can be divided into four classes: whole virus, viral vector, protein-based and messenger RNA. Those of complete virus generate immunity using a complete SARS-CoV-2 virus, although weakened, called inactivated or attenuated. There are two more candidates in this category in clinical trials in the US.
The scientists also clarify that those from viral vectors are a variation of this approach. Instead of using the entire coronavirus, they are working with a version of a harmless adenovirus that carries parts of the spike protein. Johnson & Johnson and AstraZeneca vaccines are some of those that use this technology and there are another 15 under study in the US.
The other type of injections are made from proteinwhich only need the aforementioned spike protein or part of it to generate immunity.
“Nucleic acid-based vaccines are made from genetic material, as DNA or RNAwhich encodes the spike protein of the coronavirus,” they add. There are 17 RNA vaccines and just two DNA vaccines in clinical trials in the US.
Will the new vaccines be better than the existing ones?
Rather than talk about better or worse, Upadhyay and Mallela preferred to point out that current formulations are based on the original strain of coronavirus and are less effective against new variants, while vaccines based on new variants are expected to provide better protection against these newer strains.
While it is important for these purposes to update nucleic acid vaccines, some research suggests that viral vector or whole virus vaccines might be more effective against new variants, without needing to be updated.