SINGAPORE - The two vaccines Singapore is using will protect significantly, but not absolutely, against all current variants of the coronavirus that causes Covid-19, say experts. To what extent, however, is where they do not agree. The Ministry of Health said last week that all three Covid-19 variants of concern (VOCs) - strains that could cause the most harm - as well as the two variants of interest (VOIs) behind the massive surge in cases in India, have been found in community transmissions here. VOIs have the potential to become VOCs. The three VOCs - the B117 UK variant, P1 Brazilian variant and B1351 South African variant - are of concern because they spread more easily. Though they may not cause more severe illness, there are worries that vaccines might prove less effective against them.