The global fight against COVID-19 faces an uphill battle as countries struggle to advance vaccination campaigns amid mounting cases with new virus strains reported in parts of the world.

BEIJING, Jan. 5  -- With surging new cases and strict restrictions back in place, the global fight against COVID-19 has grown tougher after the Christmas and New Year holidays.

As of Tuesday, global cases have reached 85,653,549 with over 1.8 million deaths, according to a tally from Johns Hopkins University.

DIFFERENT HOLIDAYS

The Christmas and New Year holidays, a time of family reunions, travel and shopping, have been overshadowed by a sustained record-breaking COVID-19 surge.

COVID-19 infections in the United States hit a new grim milestone of 20 million on New Year's Day, an increase of 10 million cases in less than two months.

A man wearing a face mask walks on the National Mall in Washington, D.C., the United States, on Jan. 1, 2021. (Xinhua/Liu Jie)

The CBSLA news channel reported that hospitals across the Los Angeles and other counties in Southern California had been stretched to their limits, as the county's seven-day daily positivity rate increased from 18.2 percent on Christmas Day to 21.5 percent on New Year's Day.

British Prime Minister Boris Johnson announced Monday that England will enter a national lockdown from midnight, the third of its kind since the pandemic began in the country.

Japanese Prime Minister Yoshihide Suga said Monday that the government is planning to declare another state of emergency for Tokyo and three surrounding prefectures as COVID-19 cases surge in these areas.