The number of U.S. COVID-19 deaths recorded in 2021 has surpassed the toll in 2020, reported The Wall Street Journal on Saturday based on data published by the federal government and Johns Hopkins University, demonstrating the virus's persistent menace.

The total number of reported deaths linked to the disease topped 770,800 on Saturday, Johns Hopkins data show. This puts the pandemic-long total at more than twice the 385,343 COVID-19 deaths recorded last year, according to the most recent death certificate data from the Centers for Disease Control and Prevention.

"The spread of the highly contagious Delta variant and low vaccination rates in some communities were important factors," said the newspaper. "The milestone comes as COVID-19 cases and hospitalizations move higher again in places such as New England and the upper Midwest, with the seven-day average for new cases recently closer to 90,000 a day after it neared 70,000 last month."

Meanwhile, COVID-19 has proven to be an enduring threat even in some of the most vaccinated places, many of which are confronting outbreaks again as the world prepares to live with and manage the disease for the long term, it added.

The 2021 U.S. coronavirus death toll caught some doctors by surprise. They had expected vaccinations and precautionary measures like social distancing and scaled-down public events to curb the spread of infections and minimize severe cases, said the report.

However, "lower-than-expected immunization rates as well as fatigue with precautionary measures like masks" allowed the highly contagious Delta variant to spread, largely among the unvaccinated, epidemiologists were quoted as saying.