The Pfizer Inc / BioNTech vaccine’s effectiveness in preventing COVID-19 infection drops to 47% from 88% six months after the second dose.
This is evidenced by data published in the medical journal Lancet, writes Reuters.
The analysis showed that the vaccine’s effectiveness in preventing hospitalizations and deaths remained high – 90% – for at least six months, even against the highly contagious “Delta” variant.
The vaccine efficacy against the Delta variant was 93% after the first month, dropping to 53% after four months. Against other variants of the coronavirus, the effectiveness dropped to 67% from 97%.
The data suggest that the decline is associated with decreased efficacy rather than more infectious options.