COVID-19 vaccine hesitancy: A roadblock to herd immunity?

FRESNO, Calif. (KFSN) -- The COVID vaccine rollout is about to meet a true test.

The country has reached more than 50% of adults vaccinated, but the climb to 70% or higher and herd immunity is getting steeper as it reaches the roadblock of vaccine hesitancy.

A steady stream of cars still lines up every weekday carrying people to get vaccines at Sierra Pacific Orthopedic in northeast Fresno.

This site stayed busy even when Fresno County gave up 28,000 doses last week because of a lack of demand even though just 41% of adults have received at least one dose of vaccine.

RELATED: Fresno County giving up 28,000 COVID-19 vaccine doses due to low demand in county

County health officer Dr. Rais Vohra says the virus is still killing people, so getting vaccinated is the right step to take.

"These new cases we're reporting, the vast majority of them are not vaccinated," Dr. Vohra said. "And that's really what it's all about. The longer you wait to get your vaccine, the longer you're exposing yourself to a disease that's pretty easily preventable at this point."

Still, a lot of people say they don't want to do it.

Our ABC-owned television data journalism team created a map using data from a Census Bureau survey.

RELATED: How many people in your area are hesitant to get the COVID-19 vaccine?

It shows the highest American vaccine hesitancy in parts of North Dakota and Wyoming, where more than 30% of people are not inclined to get protected.

Vaccine hesitancy among people in the Central Valley ranges from 12% in Mariposa County to 16% in Kings County, the highest rate in California.

But people giving shots here say a lot of minds are changing.

"They're taking their hesitancies and they're leaning the other way," said Rick Lembo, director of sports medicine at Sierra Pacific Orthopedic., who says people are considering both real and hypothetical vaccine requirements. "(They're) saying 'I might as well get it because I'm going to need it if I want to go to Europe in the fall or if I want to travel. If Disneyland opens and I want to have tickets. I'm going to need some verification.' Clovis Rodeo, for example."

Disneyland isn't requiring vaccinations for entry when it reopens April 30. The Clovis Rodeo is requiring proof of vaccination or a negative COVID test, as are some travel destinations, including Hawaii.

Access to travel and leisure activities may convince some people, but others need more, especially when there's a lot of vaccine misinformation spreading on social media.

Some people cite temporary pauses of vaccines to investigate reports of extremely rare side effects as a reason for hesitancy, but so far scientists have not linked side effects beyond basic allergic reactions to American vaccines.

Public health officials say all the vaccines are safe and they're very successful at cutting through hesitancy when they talk to people one-on-one about the safety and effectiveness, as they have with farmworkers.

"There was vaccine hesitancy in that group, but once we had a conversation with people, we got that number up to 90%," said Fresno County division manager Joe Prado, who's in charge of the county's vaccine rollout.

Fresno County public health officials say they'd consider literally going block by block to talk to people and bring vaccinations in neighborhoods where the rate is very low like it is in Fresno's 93701 zip code. Not even 20% of people in the central Fresno zip code are vaccinated, the lowest rate of any zip code in the Central Valley.