This suggests the vaccine is less effective against the South African variant, compared with the original coronavirus and a variant first identified in Britain that has come to comprise nearly all COVID-19 cases in Israel, the researchers said.
The researchers said the study was not intended to assess overall vaccine effectiveness against any variant, since it only looked at people who had already tested positive for COVID-19, not at overall infection rates.
Separate real-world Israeli studies on the vaccine's overall effectiveness, including by Clalit, have shown the Pfizer shot to be more than 90% effective.
South African variant may 'break through' Pfizer vaccine protection, but vaccine highly effective, Israeli study says
The researchers said the study was not intended to assess overall vaccine effectiveness against any variant, since it only looked at people who had already tested positive for COVID-19, not at overall infection rates.
Separate real-world Israeli studies on the vaccine's overall effectiveness, including by Clalit, have shown the Pfizer shot to be more than 90% effective.
South African variant may 'break through' Pfizer vaccine protection, but vaccine highly effective, Israeli study says