LONDON (AP) — Britain is deploying public health officials, supported by the army, to distribute coronavirus tests door-to-door in two northern England towns in an effort to contain a fast-spreading variant that threatens lockdown-easing plans. Cases of a strain first identified in India have more than doubled in a week. Government scientific advisers say the variant is likely more transmissible than the U.K.’s dominant strain, though it’s unclear by how much. Prime Minister Boris Johnson has warned that the variant “could be a serious disruption to our progress.” He said the next stage of lockdown-easing measures would take place as planned on Monday, but warned the variant might delay plans to lift all restrictions on June 21.