Vice Mayor Alix Desulme, City of North Miami, raises his arm during a prayer for local lives lost to COVID-19 as a memorial to those lost is unveiled at Griffing Park on October 28, 2020 in North Miami, Florida.Joe Raedle | Getty ImagesMore than 4,000 people died of Covid-19 in the United States in one day for the first time on Thursday as the country reports record-high numbers and the outbreak grows more severe by the day.The U.S. has reported a record-high daily death toll on five of the past 10 days, according to data compiled by Johns Hopkins University. Over the past week, the U.S. has reported an average of more than 2,700 deaths per day, up 16% compared with a week ago, according to a CNBC analysis of Hopkins data.Nearly 20,000 people in the country have died of Covid in January alone, setting the pace for a month that will likely rival December for the deadliest month yet of the pandemic.Top health officials, including Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, are warning that the outbreak is likely to get worse before it gets better.”We believe things will get worse as we get into January,” Fauci said Thursday in an interview with NPR. He said Americans can still “blunt that acceleration” if they strictly adhere to public health measures like mask wearing and social distancing.As of Thursday, cases were still rising quickly, a sign that more deaths will follow as people get diagnosed, become sick and enter hospitals, many of which are overwhelmed by the surge of Covid patients. The U.S. reported more than 274,700 new cases on Thursday, bringing the seven-day average up to a new all-time high of 228,400, according to Hopkins data.Daily new cases are rising nearly everywhere. The average number of daily new cases are rising by at least 5% in 44 states and the District of Columbia. New deaths are rising especially rapidly in Southern California, where health-care workers are rationing supplemental oxygen and asking ambulances to wait hours before dropping off patients.Cases and hospitalizations are rising rapidly in Arizona, as well, according to Hopkins data, a sign that daily new deaths could soon catch up. The Department of Health and Human Services announced Thursday that it was setting up an infusion center to help administer Covid antibody treatments, which have shown promise in preventing hospitalization if used early on in infection.With the outbreak growing more severe, many Americans across the country are waiting to receive one of the authorized vaccines now being rolled out. The initial rollout has been slow, with the U.S. failing to hit the goal of vaccinating 20 million Americans in December, as federal officials had aimed for.However, federal officials, including Dr. Fauci and Dr. Nancy Messonnier, director of the Centers for Disease Control and Prevention’s National Center for Immunization and Respiratory Diseases, have said the pace will likely pick up this month. The rollout has already shown some signs of slowly gaining speed.The U.S. administered more than 600,000 shots in 24 hours, the CDC reported Thursday. That’s the most in a one-day period so far, according to CDC data. More than 21.4 million doses have been distributed, according to CDC data, but just 5.9 million have been administered.Amid criticism of a slow initial rollout, HHS officials are now urging states to move beyond the first tier of prioritization. Health-care workers and residents of long-term care facilities are supposed to receive the vaccine first, according to guidance from the CDC. But HHS Secretary Alex Azar said earlier this week that states should open up to more old and vulnerable Americans if it will hasten the pace of the rollout.Also adding to the pressure to quickly vaccinate is the arrival of a new variant of the virus. The new variant, known as B.1.1.7, which was first discovered in the United Kingdom, has now been found in at least seven states. While it does not appear to cause people to become more severely sick, CDC officials say they believe it spreads more easily. That could make the outbreak even worse and quickly overwhelm hospitals, CDC officials said last week.