Japanese rubber futures slipped in thin trade on Friday as investors took profits after a three-day rally, with caution over surging cases of the Omicron variant worldwide keeping the benchmark on track for a small weekly loss. The Osaka Exchange rubber contract for June delivery , was down 0.8 yen, or 0.3%, at 232.5 yen ($2.0) per kg, as of 0234 GMT. The benchmark was headed for a 0.5% loss for the week, after last week"s 2% gain. Omicron advanced across the world, with health experts warning the battle against the COVID-19 variant was far from over despite two drugmakers saying their vaccines protected against it and signs it carries a lower risk of hospitalisation. read more Coronavirus infections have soared wherever the highly infectious Omicron variant has spread, triggering new restrictions in many countries including Italy and Greece and record new cases. read more The rubber contract on the Shanghai futures exchange for May delivery was up 40 yuan, or 0.3%, at 14,490 yuan ($2,275) per tonne on Friday. The front-month rubber contract on Singapore"s SICOM exchange for January delivery last traded at 169.1 U.S. cents per kg, down 0.5%. ($1 = 114.3400 yen) ($1 = 6.3700 Chinese yuan) Reporting by Yuka Obayashi; Editing by Subhranshu Sahu