(WASHINGTON) — A dozen states passed a major vaccine milestone Wednesday as more than 70% of their adult populations have received at least one coronavirus vaccine dose, according to health data.

The situation, however, contrasts with a handful of states, most of which are in the South, that have not broken the halfway mark with their adult residents.

A majority of the states that have broken the 70% threshold for first doses among adults are in the Northeast, such as Massachusetts, 78.7%; Connecticut, 75.6%; Maine, 74.3%; and New Jersey, 74.1%., according to the latest health data from the U.S. Centers for Disease Control and Prevention.

More states and territories are on the way to crossing this mark, including New York, 68.1%; Virginia, 67.5%; Washington state, 69.5%; and Washington D.C, 68.4%., the CDC data showed.

Other parts of the country, however, are struggling to reach 50% of adults at least partially vaccinated.

Alabama, Louisiana, Mississippi, Tennessee, West Virginia and Wyoming still have less than 50% of their adult population vaccinated with at least one COVID vaccine dose as of Wednesday, according to the CDC.

Nationwide, more than 162 million Americans over the age of 18, roughly 62.9% of the total adult population, have one vaccine dose, according to the CDC. More than 133 million American adults, roughly 52% of the entire adult population, are fully vaccinated, the CDC data showed.

States have been scrambling to increase vaccine demand, which has waned over the last couple of weeks. First dose administrations reached a peak seven-day average of 3.3 million doses administered on April 11, but that average dropped to 1.1 million on May 28, according to the CDC data.

Some states have given out incentives to increase their vaccination numbers including lotteries with million-dollar jackpots, free college scholarships for teen residents and even free beers.

The rise in vaccines has been linked to a drastic decline in cases, hospitalizations and deaths across the country, health officials said. At the beginning of April, the seven-day average for new cases reported was around 65,000, but that average has steadily dropped over the last few weeks and is now at 15,622, according to the CDC.

Recent data may have been impacted by the Memorial Day holiday, according to officials.

Anyone who needs help finding an appointment for a free COVID-19 vaccine can log onto vaccines.gov.

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