Present COVID-19 shots give a high level of protection against hospitalisation and death, as per a summary of the efficacy of eight COVID-19 vaccines that demonstrated that the Pfizer-BioNTech jab may be better at stopping at least two alarming coronavirus variants, according to University of Florida researchers.
In a paper released on May 21 before peer-review and publication, researchers Ira Longini, Julia Shapiro, Natalie Dean, and colleagues at the university said the efficacy against COVID-19-linked disease averaged around 85% after a full course, increasing to almost 100% protection against severe disease, hospitalisation or death.
They compared data from media reports and journal articles for products that have gone through placebo-controlled, double-blinded, late-stage trials, in addition to observational studies.
"These estimates should be useful for constructing mathematical models for vaccination impact and for making policy decisions involving vaccination," the researchers said, according to Bloomberg. They also plan to update their research, which secured funding from the US National Institutes of Health, as more information becomes available.
The unprecedented speed at which effective and safe COVID-19 vaccines have been developed and rolled out across the globe, has made it possible for several economies to reopen, clearing the way for recovery from the worst pandemic seen in a century. Yet, the wild spread of coronavirus risks producing new variants that may sabotage the potency of these inoculations.
The University of Florida researchers further said that protection against any disease with infection for three so-called strains of concern averaged 86% for the B.1.1.7 variant first identified in the UK, 61% for the P.1 strain that spurred an explosive outbreak in Brazil, and 56% for the B.1.351 variant detected in South Africa.
They added that vaccine efficacy was evaluated for inoculations that are being rolled out on local and global scale, the researchers noted. These comprise the AstraZeneca Plc, Johnson & Johnson, Moderna Inc., Novavax Inc., Pfizer, Sputnik V, Sinopharm Group Co., Sinovac Biotech Ltd. products.
"Some of the estimates are based on rigorous, pre-planned statistical analyses from double-blinded, placebo-controlled trials, while others are extracted from observational studies with different levels of control," the researchers noted.
They further stated that the vaccine efficacy against infectiousness was 54% on average, suggesting that vaccination lowers the direct transmission of COVID-19 to others by 54%.