By Amy Norton
THURSDAY, March 12, 2015 (HealthDay News) -- In the wake of the measles outbreak that has generated headlines for months, more Americans now say they have positive feelings toward childhood vaccinations, according to a new HealthDay/Harris Poll.
Of more than 2,000 adults surveyed, 87 percent said they thought that the vaccines routinely given to young children are safe. That's up from 77 percent from a similar poll last July.
Among the new poll's other findings:
- 82 percent of respondents say childhood vaccinations should be mandatory for all children, up from 77 percent in the July poll.
- 79 percent say there's at least a moderate level of risk that an unvaccinated child could contract a disease that vaccinations are designed to protect against. That's an increase of 5 percentage points since the July poll.
- 69 percent say a child contracting a vaccine-preventable disease such as measles would present at least a moderate danger to other children, up from 64 percent in July.
The new poll also revealed that 77 percent of adults believe that parents who don't want their children vaccinated should be required to get a doctor's certificate showing why they chose not to have them vaccinated. And 72 percent think that if a child is not vaccinated, he or she should not be allowed to attend school.
There's also been a small but measurable shift in the understanding of what's called "herd immunity." Less than a year ago, roughly three in 10 Americans (29 percent) agreed that since most children get vaccinated, it's alright if some parents choose not to vaccinate their children. Today, roughly two in 10 (21 percent) agree with that sentiment, the poll found.
Dr. Aaron Glatt, a spokesman for the Infectious Diseases Society of America, sees the shift as encouraging. And while the reasons for it aren't certain, it's safe to assume that the measles outbreak is the driving force, he said.
"I think the measles outbreak is causing some people to re-examine their 'facts' about childhood vaccinations," Glatt said. "Unfortunately, sometimes it takes a scare."
"Perhaps the most alarming numbers are the 32 percent of parents with children under 6 who think there is at least a moderate chance that vaccinations may cause autism -- and the 24 percent who believe there is scientific research to show this," said Humphrey Taylor, chairman emeritus of the Harris Poll.
Glatt agreed that those numbers are concerning, though not surprising. Parents of young children are understandably more likely to go looking for information on vaccinations. But that increases the chances of coming across misinformation, he said.
The ongoing measles outbreak got its start at two Disney theme parks in southern California in December. As of March 6, 173 people in 17 states and the District of Columbia had been infected, and most of those people had never been vaccinated, according to the U.S. Centers for Disease Control and Prevention.
Measles was declared eliminated in the United States back in 2000. But outbreaks have occurred since, with the largest so far arising last year -- when 644 people in 27 states fell ill, according to the CDC.
The problem, the agency says, is that travelers can bring measles to the United States, and the virus spreads if people aren't vaccinated.
In recent years, some American parents have decided to either skip the MMR and other childhood vaccines, or ask their doctors to delay certain shots -- often due to fears over vaccine safety. Those worries date back to 1998, when a small study claimed to show a link between the MMR vaccine and autism. The study has since been widely discredited, and the British doctor who led it lost his medical license.
"That 'link' was based on falsified data," Glatt said. "But the idea that the MMR causes autism is still out there."
In the new poll, the "Millennial" generation (those born between the early 1980s and the early 2000s) was most likely to believe the MMR-autism claim: 22 percent. That compares to 18 percent of "Gen Xers" (those born between the early 1960s and the early 1980s); 12 percent of baby boomers; and 8 percent of Americans older than 70. Glatt said it's not surprising that younger Americans have more negative views of vaccines compared to older Americans -- partly because they've never seen potentially fatal diseases like measles or polio.
One poll finding was somewhat surprising, though, according to Glatt. There's a common perception that vaccine detractors in the United States are largely from upper-income brackets.
But the poll found that people with the highest-income households -- earning $100,000 or more a year -- were less likely to believe in the MMR-autism link -- only 12 percent did, versus 22 percent of people from households earning less than $50,000.
"I think that tells us there is no standard 'type' of parent who is a vaccine doubter," Glatt said. "The issue is more widespread than that."
The poll, conducted online between Feb. 25-27, included a nationally representative sample of 2,032 U.S. adults.