One of the biggest concerns that currently exist is the vaccine resistance of the different variants that have emerged from COVID-19. Of particular concern is Delta variant, originally from India, which has been shown to be more contagious. Specifically, it is a 64% more transmissible than Alpha variant (detected in the United Kingdom), according to estimates by the public health agency Public Health England (PHE). Right now, it is already predominant in the UK and the European Center for Disease Control and Prevention estimates that it could cause 90% of infections in the European Union at the end of summer.
The good news is that there are two drugs that have shown high effectiveness against it. “The two doses of Pfizer or AstraZeneca are effective enough to control this variant.They provide a good immune response and are effective in preventing hospitalization, ”Ignacio López-Goñi, a microbiologist from the University of Navarra, explained to EFE a few days ago. However, he warns that “some escape from neutralizing antibodies has been detected at an experimental level, and less efficacy with one dose of vaccine”.
Pfizer / BioNTech
“With the data we have today from the studies we are doing in the laboratory and which include information on the places where Delta has already replaced the British variant (now called Alpha) as predominant, our vaccine is being very effective, about 90% in preventing disease”Says Alon Rappaport, Pfizer’s chief medical officer in Israel.
For his part, PHE from England determined in a investigation that the Pfizer and BioNTech drug had a 96% effective against Delta variant to prevent hospitalizations and 88% to avoid symptomatic COVID-19, versus 94% and 33% efficacy with a single dose, respectively.
A study published this month in Nature and conducted by the University of Texas in collaboration with Pfizer-BioNTech also concluded that the vaccine antibodies they were capable of neutralizing all known variants, including the Delta.
Regarding the vaccine developed by AstraZeneca, the PHE assures that it shows a 92% efficacy against Indian variant in the prevention of hospitalizations and 60% in avoiding symptomatic casesversus 71% and 33% with one dose, respectively. claiming that it is a lower figure than the previous vaccine for several reasons, among which is that this serum needs more time to reach maximum levels of effectiveness.
No information from Janssen and Moderna
In the case of drugs created by Janssen and Moderna, at the moment no studies have been conducted that demonstrate the effectiveness or loss of this against the Delta variant.