LONDON (AP) — Scientists are warning the British government not to weaken the country’s ability to monitor and track coronavirus when Prime Minister Boris Johnson ends the requirement for people in England to self-isolate if they contract COVID-19. Johnson will announce details in Parliament on Monday of the government’s plan for “living with COVID.” The legal requirement to self-isolate after a positive coronavirus test is expected to end and mass testing for the virus will be scaled back. Andrew Pollard, director of the Oxford Vaccine Group, said “the decision about when and how to reduce restrictions is enormously difficult.” But he said it was crucial to keep up surveillance as “an early warning system” for new variants.