Vaccine efforts across the United States are falling well short of the Trump administration’s target of getting 20 million Americans vaccinated by the end of the year. As of Thursday, just 3.17 million people in the U.S. had received the coronavirus vaccine, according to data compiled by Bloomberg and the Centers for Disease Control and Prevention (CDC).

Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told Yahoo Finance Live this week that we’ll likely see “many more hiccups” throughout the distribution efforts over the next several months due to a lack of adequate public health infrastructure.

“Many of us in the field knew that this wasn't going to be something that was easy,” Adalja said. “And a lot of us cautioned against coming up with specific numbers by a specific date that would be vaccinated because when you're doing something this big, and you're doing something with vaccinations, there were bound to be delays and hiccups.”

‘There is a learning curve’

U.S. officials are blaming a few factors for the delay: holidays, winter storms, and a “learning curve” when it comes to vaccine distribution. Moreover, some states have held back doses for residents of nursing homes and long-term care facilities, according to The New York Times, which also noted that vaccine distribution has fallen to hospitals that are already over-burdened.

“The number is lower than what we had hoped for... There is a learning curve,” Operation Warp Speed chief scientific adviser Dr. Moncef Slaoui told reporters this week. “A number of days have been lost because of ... holidays and snowstorms. We’re learning. We continue to seek specific input from others to help further accelerate the uptake.”

Meanwhile, President Donald Trump took to Twitter on Wednesday to say it’s up to the states to distribute the vaccines at a faster pace.

Vaccinations in the U.S. started Dec. 14, with the CDC recommending that frontline workers and those over 74 receive the first doses. As of Wednesday, more than 14 million doses of Pfizer (PFE) and Moderna’s (MRNA) vaccines had been distributed nationwide, according to Operation Warp Speed Chief Operating Officer Gustave Perna. On Jan. 1, The New York Times reported that New York City was still far from its goal of vaccinated 10%-20% of the population — in the first 17 days of the rollout, just 1% of city residents had received their first of two vaccine doses.

Earlier this week, President-elect Joe Biden criticized the Trump Administration’s vaccine distribution efforts, saying that at the current rate, it would take “years, not months” to vaccinate the American people. Biden has pledged to invoke the Defense Protection Act to help get 100 million Americans vaccinated in his first 100 days in office.

The slower vaccine rollout comes as coronavirus cases continue to surge and a new, more contagious COVID-19 variant is detected in the U.S. A record of more than 125,000 people in the U.S. were hospitalized due to COVID-19 as of Thursday, pushing many hospitals to max capacity.

Despite the hiccups and delays in vaccine distribution, there is a silver lining — the process has started. And while vaccinations won’t change the trajectory of the virus immediately, Adalja says getting the most vulnerable population vaccinated should help reduce future hospitalizations and mortality this spring.

“The first impact you'll see is when we start to get the vulnerable populations vaccinated,” Adalja said. “If we could get the nursing home population vaccinated quickly then we would start to have some breathing room in hospitals... I suspect probably in late winter, early spring, we'll start to see some real benefits of the vaccinations.”

Seana Smith anchors Yahoo Finance Live’s 3-5 pm ET program. Follow her on Twitter @SeanaNSmith

READ MORE:

• Ex-Surgeon General decries politicization of COVID-19, calls it as deadly as the virus itself

• COVID-19 pandemic has forced women out of the workforce creating a 'she-cession'

• Economy is ‘schizophrenic’ as coronavirus surges: Moody’s chief economist

• The US could face an 'apocalypse’ by Christmas as COVID-19 cases surge

• Coronavirus surge and no stimulus will result in ‘empty storefronts’ nationwide

• Trump blocking Biden team from accessing coronavirus data is 'criminal': ex-HHS secretary