According to Health Ministry studies, the effectiveness of the Pfizer coronavirus vaccine against infection from the Delta variant drops to just 39%, Channel 12 News reported.
The effectiveness in preventing serious illness has also decreased, but it is still high and stands at 91%.
However, the sample from which the data was taken is not large because the number of patients is now severely low. The health system will continue to collect data.
The ministry wants to ascertain whether there is a difference in the effectiveness of the vaccine between those who were vaccinated in January and those who took the vaccine a few months later.
The ministry emphasized that the current data shows the vaccine remains highly effective in preventing serious illness even if it is less effective in preventing infection.