While many people say they are taking the flu shot to protect themselves against the virus, about 70% of adults and 50% of children aged 2 to 17 in the United States are receiving the vaccine, according to a report released Tuesday by the National Center for Health Statistics.

The number of people who were vaccinated has increased steadily over the past decade as more states and the federal government have added more state and local vaccine coverage.

The Centers for Disease Control and Prevention, the research arm of the nation’s health agency, estimates the number of adults who received the vaccine during the first half of 2019 was around 5.3 million.

That number has now climbed to 6.3 billion.

It is unclear whether the spike in coverage is due to increased vaccination or whether the increased uptake is because of a more comprehensive flu vaccine.

The CDC said it is not yet sure why more people are receiving their shots.

It has been encouraging people to get vaccinated in recent months and have more children, especially those under age 6, to boost their vaccine coverage, Dr. Mark Kessler, an assistant professor at Johns Hopkins University School of Public Health, said in an interview.

However, the data suggests that, in some cases, more people have been getting vaccinated.

The vaccine is given as two shots in a four-dose series, or as two doses, or in a single shot, according the CDC.

The rate of children who are vaccinated also rose, but the rate was still lower than the rate of adults, which rose to 65% from 69%.

About 2.4 million people aged 1 to 17 were receiving the flu vaccine, up from 1.9 million in the first three months of 2019, according a report by the CDC published Tuesday.

The numbers of those receiving the shots were unchanged from the previous year.

The total number of children and teens who were receiving shots increased to 2.7 million in 2019 from 2.5 million in 2018.

The number of teenagers was about 1.8 million from 1 million last year.