"Vaccine Hesitancy" Fuels Outbreaks

Map of the U.S. with text that reads: In 2018, the U.S. experienced 349 confirmed measles cases and 17 measles outbreaks. Among measles patients, 1 in 4 will be hospitalized, 1 in 1,000 will develop encephalitis, 1 to 2 in 1,000 will die. Don't Wait...Vaccinate!
A recent study by the National Conference of State Legislatures found that 12 states with liberal vaccine opt-out laws have high rates of "unimmunized, unprotected children" -- raising the specter of an epidemic that "could either originate or spread rapidly throughout these populations."

With the start of a new school year upon us, no fewer than 15 major metropolitan areas in the U.S. have "hotspots" of unvaccinated children that make them vulnerable to preventable diseases similar to the recent measles outbreak in New York City, experts warned in a recent webcast. The trend has major implications for health centers, health departments, hospitals and schools alike.

Spread by social media networks -- one Baylor University researcher counted more than 400 anti-vaccine websites in a recent survey -- collective opposition to immunizations among like-minded parents has sprung up in the U.S. and Europe, even as stepped-up vaccine campaigns in Africa have dramatically cut infection and death rates.

The result: Preventable diseases like measles and whooping cough that had been all but eliminated in the industrialized world are now making a comeback, the experts say.

Measles at their highest level in 25 years

A bar chart using CDC data that shows the number of measles cases between 1950 and 2019. Measles reached a peak of 763,000 cases in 1958. Fast-forward 42 years and it was eliminated in the U.S. In 2019, the virus has mounted a comeback, reaching its highest level in 25 years. An inset bar chart shows cases since 2000, with a peak of 1,044 cases in 2019 (through June 13, 2019). For detailed data: https://www.cdc.gov/measles/cases-outbreaks.html

A global vaccine initiative HRSA Exit Disclaimer launched in 2000 has markedly reduced worldwide outbreaks of preventable maladies among children under five years of age. But the World Health Organization reported this year that "vaccine hesitancy" is now among the 10 leading global health threats, said webcast moderator Katherine Bliss of the Center for Strategic and International Studies' Global Health Policy Center.

Urban anti-vax hotspots in the U.S. include Seattle, Spokane, Portland, Phoenix, Salt Lake City, Houston, Fort Worth, Austin, Detroit and Kansas City. Pockets of vaccine resistance also have been found in smaller counties HRSA Exit Disclaimer in Indiana, Wisconsin and Utah. A recent study by the National Conference of State Legislatures found one county in Idaho HRSA Exit Disclaimer in which nearly a third of kindergarteners had not been immunized -- and 7 more Idaho counties with some of the highest opt-out rates among the western states.

Urban centers are especially vulnerable to fast-moving, contagious outbreaks, noted Dr. Peter Hotez, of the Baylor College of Medicine, a study co-author, vaccine scientist, and father of an autistic daughter -- who stressed that rigorous research worldwide has debunked the notion that vaccines "have anything to do with autism." Among those studies, the Institute of Medicine in 2011 and the CDC in 2013 concluded that there is "no link between vaccines and autism."

From left, Katherine Bliss, Center for Strategic and International Studies; Dr. Peter Hotez, Baylor College of Medicine; and Dina Borzekowski, University of Maryland.
From left, Katherine Bliss, Center for Strategic and International Studies; Dr. Peter Hotez, Baylor College of Medicine; and Dina Borzekowski, University of Maryland.  The panelists agreed that non-medical vaccine opt-out provisions are increasing the likelihood of regional epidemics. August was National Immunization Awareness Month.

Concerns that vaccinations could be linked to autism began to spread in 1998 with publication of flawed research findings in The Lancet. The article in the esteemed British journal was formally retracted in 2010, but its effects still reverberate, Hotez said.

"Even a five percent reduction in MMR (Measles, Mumps and Rubella) vaccine coverage can lead to a three-fold increase in annual measles cases," he noted.

"It has been estimated that for each U.S. birth cohort receiving recommended childhood immunizations, around 20 million illnesses and more than 40,000 deaths are prevented, resulting in $70 billion in savings," observed a 2016 NIH study. HRSA-supported health centers immunize more than 150,000 U.S. children by age two each year -- and the agency's Title V block grant program pays for thousands more.

But state Title V administrators continue to report high rates of hesitancy. Michigan officials, for example, observed in a 2017 report to HRSA's Maternal and Child Health Bureau that "on-schedule vaccinations have become increasingly difficult as many parents have questions about vaccines, and vaccine hesitancy appears to be increasing. Michigan immunization rates have remained at 75 percent, which is the same as the previous year."

A photo of Dr. Michael Warren with the caption: "Vaccines protect not only those children and adults who receive them, but also the minority of individuals who cannot--such as those who have suppressed immune systems and rely on the rest of the community to be vaccinated to help keep them healthy and safe."  - Dr. Michael Warren, Associate Administrator, HRSA Maternal and Child Health Bureau
Currently, 18 states allow non-medical exemptions to immunizations.  In at least six of those states, the number of parents opting out of childhood immunizations continues to grow.

Similarly, certain foreign countries have seen a spike in anti-vaccine sentiment and measles in recent years. Travelers from abroad are contributing to the measles surge in the U.S., along with domestic skeptics.

Through July 25, some 1,164 individual cases of measles have been confirmed in 30 states, the CDC reports; it's the most cases reported in the U.S. since 1992 and since measles was declared eliminated in 2000. Outbreaks in New York City and Rockland County, New York have continued for more than 9 months this year, the CDC reports.

Vaccine hesitancy is plainly perpetuated on the Internet and social media, said University of Maryland professor Dina Borzekowski, an expert in the area of children, media, and health.

A recent study found that mothers who do not support childhood vaccinations were more likely to discuss the issue online, "including seeking, sharing and forwarding the information on social media," said Borzekowski, adding that the virtual community of vaccine opponents "is separate, but robust (and) a network that is distinct and separate from ... online pro-vaccine communications."

Related to this, while 'mainstream media' reporting is overwhelmingly pro-vaccine, opponents get their news from other platforms.

This suggests the "quite urgent" need to have one's vaccine qualms addressed in person, by health care professionals and scientists.

"It is important for practitioners to use trusted relationships to hear people's concerns and dispel … information directly," Borzekowski recommended.

View the webcast HRSA Exit Disclaimer, hosted by the Consortium of Universities for Global Health. HRSA administers the National Vaccine Injury Compensation Program, which provides compensation to people injured by certain vaccines. Visit the site for more information.

Date Last Reviewed:  September 2019