In 10 seconds? Current Covid-19 vaccines’ efficacy is lower against the rapidly spreading Delta variant than previous strains, researchers suggested.

What have researchers discovered? In a pre-print published study (not peer-reviewed by third-party scientists), the predicted efficacy of the Moderna jab against infection by the Delta variant was found to be 71.4%, i.e 20% lower than against earlier ‘prototype’ viral strains. The AstraZeneca-Oxford vaccine fared even worse: offering 50% less protection at only 27.5%. (see Column A in the chart below) The team has also analyzed protection offered against symptomatic disease caused by the Delta variant offering a somewhat better protection (Column B in the chart). However, when comparing severe Covid-19 caused by the Delta variant, the Moderna vaccines provided almost 100% protection, Pfizer was estimated to provide 75.3% protection while Johnson&Johnson’s efficacy was predicted at 56.9%.

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