Data released Tuesday by the U.S. Centers for Disease Control and Prevention says the actual number of coronavirus infections in some parts of the United States is anywhere between two to 13 times higher than what has been officially reported. The CDC based its conclusions on blood samples collected from people who were given routine clinical tests across 10 geographic regions, including New York City, south Florida, Missouri and the western states of Utah and Washington. In Missouri, for example, the estimated number of actual infections was 13 times higher than the number of confirmed cases, while in Utah, the actual number was at least twice as high.   The authors of the study, which was also published on the website of JAMA Internal Medicine, said many infected people did not seek medical care or get tested because they likely had mild symptoms or none at all, and likely spread the virus among the population.  At least 40% of people who are infected do not develop symptoms.   The CDC researchers also found that only a small number of people in many parts of the United States were carrying the coronavirus antibodies as of late May, indicating that most of the population remains highly at risk of infection.   In New York City, the initial U.S. epicenter for the COVID-19 pandemic, nearly 24% had the antibodies for the disease, well below the 60% threshold scientists say is needed to achieve herd immunity, the point at which enough people would be immune to the coronavirus.   The numbers were far lower in other parts of the country — Philadelphia was at 3.6%, Missouri was 2.8%, and Utah was just 1.1%.Visitors walk around Liberty Island on its first day of reopening since the start of the coronavirus pandemic, Monday, July 20, 2020, in New York. The Statue of Liberty remains closed.The figures were released on a day when the United States posted more than 1,000 coronavirus deaths, the first time since early June the U.S. reached the grim single day milestone. In his first formal daily White House coronavirus briefing since late April, President Donald Trump acknowledged the number of COVID-19 cases was spiking across the country, saying the situation “will…get worse before it gets better.”  With more than 14.8 million confirmed novel coronavirus cases and more than 613,000 fatalities, researchers are reporting progress on the race to develop a safe and effective vaccine against the disease.  The first possible U.S. vaccine is set to begin final-stage testing next week in a study of 30,000 people to see if it really is safe and effective, according to an Associated Press report.  In Brazil, which is second to the United States in both the total number of confirmed infections  (2.1 million) and deaths (81,487), health authorities on Tuesday approved human testing of a potential COVID-19 vaccine developed jointly by U.S. pharmaceutical company Pfizer and German-based BioNTech. Approval of the experimental vaccine came on the same day researchers began a  three-month late-stage human testing of another new vaccine developed by Chinese-based pharmaceutical company Sinovac. Hundreds of doctors and other healthcare workers across six Brazilian states will receive the vaccine, which is being coordinated by Sao Paulo-based Butantan scientific institute.  If the vaccine proves to be safe and effective, Brazil would receive as many as 120 million doses at the start of next year, enough to immunize 30 million people.   Late-stage clinical trials are also taking place in Brazil of a COVID-19 vaccine developed jointly by Britain’s Oxford University and British-Swedish drugmaker AstraZeneca. Meanwhile, the United Nations International Children’s Fund said Tuesday the closing of educational facilities due to the coronavirus pandemic has resulted in at least 40 million preschool students worldwide missing out on learning and development.