Clinicians push back against vaccine myths

Despite the body of literature supporting their use, vaccines are still not fully accepted by the public, which increases the risk for outbreaks of preventable diseases, including measles, in regions where they had been greatly diminished.

Photo by Jack Kearse, Emory University

In the United States, the proportion of parents who refused one or more vaccines for their children increased from 9.1% in 2006 to 16.7% in 2013, according to results of a survey conducted by the American Academy of Pediatrics (AAP).

“People refusing vaccines are not the majority but a tiny group of people who tend to cluster together,” Christoph Diasio, MD, FAAP, chair of the AAP section on administration and practice management, told Infectious Disease News.

The good news is that the trend in vaccine refusal appears to have receded somewhat after the Disneyland measles outbreak in California in 2015, according to Diasio.

“What happened in Disneyland resonated with a lot of people, which helped our case as physicians and health care professionals with regard to the importance of vaccinations,” he said.

However, staunch opposition continues to endanger public health, experts suggest. Reasons for vaccine hesitancy or refusal, they said, include the belief that vaccines are unsafe or ineffective, as well as misplaced blame for adverse events.

Such misconceptions can blind people to the dangers of not getting immunized.

“I think the big issue is that, aside from smallpox, these diseases are continuing to circulate in the U.S. or are a plane ride away,” Walter A. Orenstein, MD, an infectious diseases professor at Emory University and associate director of the Emory Vaccine Center in Atlanta, said in an interview.

“I think it’s critical to get across to people that all of these pathogens are circulating elsewhere in the world and that the absence of disease today doesn’t mean it will be absent tomorrow.”

Infectious Disease News spoke with several experts about some of the reasons behind vaccine refusals, how a new administration’s stance on vaccination is causing concern in the scientific community, and the clinician’s role in persuading patients to take advantage of one of the greatest medical achievements in history.

Lingering misconceptions

According to Orenstein, several factors influence vaccine refusal.

“One is the issue of safety,” he said. “There has been a variety of concerns in recent years; probably since 1998 in the U.S., the concern about autism is one of the major ones.”

A fraudulent study led by Andrew Wakefield and published in 1998 in The Lancet claimed that the measles-mumps-rubella (MMR) vaccine had caused autism in 12 children, giving rise to a myth that has proven difficult for physicians to overcome. The science, reviewed by independent medical organizations, has shown clearly that the evidence does not support vaccines playing a role in causing autism.

Another obstacle to vaccine acceptance is a “tremendous lack of understanding” of how vaccines are licensed and recommended for use and the processes in place to ensure their safety and efficacy, Orenstein explained. Vaccines usually take years to develop, he said, involving preclinical work, three phases of clinical trials, and a careful review of the evidence by the FDA before a license is granted.

The cost of developing a single vaccine ranges from $500 million to $1 billion or more, according to a recent estimate. Only about 7% of vaccines in preclinical development find their way to market. Further, there is extensive post-marketing surveillance to evaluate whether vaccines cause serious adverse events. This includes the Vaccine Adverse Event Reporting System (VAERS) — a national vaccine safety surveillance program that allows health care providers and the public to report suspected adverse events, and the Vaccine Safety Datalink, which helps determine whether vaccines are causing a specific adverse event by comparing the incidence of the event in vaccinees with the incidence in nonvaccinees.

Most recommended vaccines are highly effective.

“For example, measles [vaccine] is about 93% effective with one dose and 97% effective with two doses,” Orenstein said.

However, doubts about the efficacy of certain vaccines, particularly those for influenza, can also hamper efforts to reduce that disease.

“I think with influenza, there’s the perception that the vaccine is not effective,” he said. “Influenza vaccine effectiveness is generally on the order of 50% to 60%, which is good efficacy although not ideal.

“We need to explain to people that the flu is a syndrome, and it’s caused by many things, including the influenza virus,” Orenstein continued. “The influenza vaccine will only protect against that portion of the syndrome caused by the influenza virus. People with clinical illnesses compatible with the flu but caused by other viruses will not be impacted by influenza vaccine. ... However, influenza vaccine, while not 100% effective, markedly reduces your odds of getting an illness caused by influenza viruses. It’s certainly something I would want to do, and in fact I always make sure I get an influenza vaccine annually.”

Reasons for vaccine refusal varied among parents in a 2009 survey published in Pediatrics. The data included nationwide responses from 1,552 parents of children aged 17 years and younger.

Overall, 90% of parents agreed that vaccinating their children is a good way to protect them from disease. However, 11.5% said they had refused at least one vaccine for their children, and 54% were concerned about potential serious adverse effects of vaccines. In addition, 25% felt that some vaccines cause autism, and 11% said their children did not need vaccines for diseases that are no longer common.

Women were more likely than men to be concerned with potential serious adverse effects (60% vs. 46%; P = .0007). Broken down by ethnicity, 37% of Hispanic parents believed vaccines cause autism, compared with 23% of black parents and 22% of white parents (P = .01).

Despite the science behind vaccines, parents are being misinformed by friends and the internet, according to Infectious Disease News Editorial Board member Amy B. Middleman, MD, MPH.

“Unfortunately, right now, science is being trumped by anecdote,” Middleman, a professor of pediatrics and chief of adolescent medicine at the University of Oklahoma Health Sciences Center, said in an interview. “And that’s a really dangerous position to be in, because we know we’re seeing a lot more disease outbreaks in areas where immunization rates are low.”

She added that concerns frequently center on information from VAERS. Middleman said she explains to patients that VAERS is meant simply to alert people to adverse events that occur after immunization and may be related to vaccines. There is not necessarily a cause-and-effect link between the vaccine and an event, she tells them.

A new administration’s stance

Clinicians worry that a major obstacle to vaccine acceptance occupies the Oval Office.

During the campaign that brought him to the White House, then-candidate Donald J. Trump cited Wakefield’s discredited study, and in August 2016 met with Wakefield and a group of other anti-vaccination activists. Additionally, Trump suggested without evidence that smaller doses of vaccine given over a longer time period would prevent autism.

A request by Infectious Disease News for clarification of the president’s position on vaccination from the White House was not answered.

Anxiety over the administration’s policy on vaccination deepened when, in January, environmental attorney Robert F. Kennedy Jr. announced that Trump had asked him to chair a vaccine safety committee. Kennedy is a proponent of scientifically disproven claims about the safety of vaccines — particularly those focusing on the use of the mercury-containing preservative thimerosal in certain vaccines and the link to neurological disorders in children, including autism.

Trump’s transition team denied the claim and issued a statement saying the president was “exploring the possibility of forming a committee on autism, which affects so many families; however, no decisions have been made at this time.”

Regardless of whether he will have the president’s ear on the issue, experts refute Kennedy’s claims.

“RFK Jr.’s question about whether thimerosal is dangerous has been asked and answered,” Paul A. Offit, MD, director of the Vaccine Education Center and professor of pediatrics in the division of infectious diseases at The Children’s Hospital of Philadelphia, told Infectious Disease News in a previous interview.

“There are seven studies that have looked at this question and all have found the same thing, which is thimerosal at the level contained in vaccines is not harmful. So, his skepticism about thimerosal is reasonable, but if you have evidence then showing that it’s not a problem, why don’t you believe it?”

In 2001, thimerosal was reduced or removed completely from all U.S.-marketed vaccines for children aged 6 years or younger merely as a precaution, according to the CDC. MMR, varicella, inactivated polio and pneumococcal conjugate vaccines had never contained the preservative, and influenza vaccines are available both with and without it, the agency said.

Kennedy, too, did not respond to a request for comment.

In a more recent interview, Offit said he does not think Trump’s beliefs will impact vaccine policy.

“I think, really, it doesn’t mean anything,” Offit said. “Donald Trump met with Al Gore the day before he appointed Scott Pruitt and Rick Perry to head the EPA and Department of Energy. They’re two climate change deniers. I think that this will not affect vaccine policy.”

Nonetheless, Offit conceded that Trump’s attitude toward vaccines could encourage those who are opposed to them.

“You could argue that he has emboldened the antivaccine groups, that they may feel they have a friend in the White House,” he said. “Because he, like them, is willing to ignore the evidence.”

In February, more than 350 health care organizations from across the U.S. attached their names to a letter to Trump asking him to embrace the breadth of research indicating that vaccines are safe and effective.

The AAP, AMA, Autism Science Foundation and Children’s Defense Fund were among those groups. The letter cited the worldwide eradication of smallpox in 1977 and of polio in the Western Hemisphere in 1991 as just a few of the fruits of vaccination.

“Claims that vaccines are unsafe when administered according to expert recommendations have been disproven by a robust body of medical literature, including a thorough review by the Institute of Medicine,” the letter read.

“Delaying vaccines only leaves our nation’s citizens at risk for disease, particularly children. As a nation, we should redouble our efforts to make needed investments in patient and family education about the importance of vaccines in order to increase the rate of vaccination among all populations.”

Tackling HPV vaccine stigma

In the 2009 Pediatrics survey, HPV vaccine was the most commonly refused, with 56.4% of parents declining it.

Efforts to increase HPV vaccination often are met with parental fears that it is unsafe and encourages teens to have sex. The AAP suggests that reassuring parents of the vaccine’s safety and pointing out that there is no evidence that it increases sexual activity may dispel those fears.

“The bad news is that only 60% of girls and 40% of boys are getting that first dose of the HPV vaccine, and only 40% of girls and 20% of boys are actually getting all three doses,” Gary S. Marshall, MD, professor of pediatrics, chief of the division of pediatric infectious diseases and director of the Pediatric Clinical Trials Unit at the Louisville School of Medicine, told Infectious Disease News.

“This is absolutely mind-boggling to me. If I was told back when I was in training that we would one day have a vaccine that will protect against cervical, penile and anal cancer, and most likely against oral cancers, this would have been hard for me to believe.

“However, it would be even more unimaginable that people are refusing to take the vaccine that prevents these cancers,” Marshall added.

Middleman was just as perplexed by the dismal uptake in HPV vaccine.

“There are some parents who still don’t fully understand that this is a vaccine against cancer,” she said, “and emphasizing that is hugely important. There are also a lot of parents who don’t understand that the younger a child is when the vaccine is given, the more vigorous the immune response. I try to make that clear to parents.”

Middleman said she emphasizes that there is a window of opportunity for optimal response to HPV immunization.

“I also make it clear that I gave it to my own children as soon as I was able because, as a parent, that is my job — to protect them when I have the opportunity to do so,” she said.

In contrast to many other childhood vaccines, one of the biggest reasons for foregoing the HPV vaccine is not parental refusal but the provider’s failure to even discuss it, according to Kenneth A. Alexander, MD, PhD, chief of allergy, immunology, rheumatology and infectious diseases at Nemours Children’s Hospital in Orlando, Florida, and professor of pediatrics at the University of Central Florida College of Medicine.

“If the pediatrician does bring it up, it is brought up very poorly and is talked about in the wrong way,” Alexander said in an interview.

“The conversation around HPV vaccination has been mishandled. We have focused on the wrong thing. There is this idea that if we immunize a child against HPV, that they all of a sudden become crazy sex fiends,” he said. “This is absurd and is very demeaning to our young people. We now have the scientific data that proves this idea is completely off-base.”

The clinician’s role

In their push to win over vaccine detractors, clinicians have plenty of convincing literature in their arsenal.

According to researchers, vaccines created from a human cell strain have prevented 4.5 billion disease cases and saved 10.3 million lives worldwide in the past 5 decades.

The study, published in March in AIMS Public Health, estimated the impact of the WI-38 strain developed by Leonard Hayflick, PhD, in 1962. The strain has been used to produce vaccines for polio, measles, mumps, rubella, varicella, herpes zoster, adenovirus, rabies and hepatitis A virus.

The researchers estimated that, in the U.S. alone, the vaccines prevented or treated 198 million cases of those diseases between 1962 and 2015 and averted 450,000 deaths in that period.

A study published the same month in The LancetInfectious Diseases demonstrated the efficacy of the MMR vaccine.

In that study, Iro and colleagues analyzed data from 16,571 admissions for encephalitis related to measles and mumps in England from 1979 to 2011. The researchers found that admissions for measles-related encephalitis decreased by 97% and mumps-related encephalitis fell 98% after the two-dose MMR vaccine was introduced in 1996.

Despite such evidence, Orenstein said, combating stubborn vaccine myths is more difficult than one might expect.

“What we need, in my opinion, is more research on what I call implementation science, how to transmit the information,” he explained.

One method is to make the vaccine discussion presumptive rather than participatory, or open to possible objection, he said.

“In a presumptive conversation, we would say, ‘Johnny is due for these vaccines today: A, B and C,’ ” Orenstein said. “In a participatory conversation, we would say, ‘Johnny could get vaccines A, B and C. What do you think?’ And we know from the research that the presumptive is more effective.”

Clinicians can also direct patients to authoritative sources.

“There are tools that are available on the CDC website,” Orenstein noted. “There’s [also] the Immunization Action Coalition, which has some very helpful materials, and the Vaccine Education Center at the Children’s Hospital of Philadelphia.

“There are others as well,” he said. “But I think being able to refer people to these websites to get more information would be very helpful.”

Like Middleman, Orenstein tries to identify with patients and parents on a personal level.

“What I often try to do when I talk to hesitant people concerning a given vaccine is say that this is what I give myself or to my children or grandchildren, to put a personal touch on it, so it’s not in the abstract.”

Some physicians, to protect other patients in their clinics, avoid treating those who refuse vaccination. Orenstein stops short of such an approach.

“I would prefer to keep a relationship with those hesitant people in the hope of eventually persuading them, rather than having them go to a provider who’s completely against vaccination,” he said.

For Middleman, opposition to vaccines is often rooted in a post hoc mentality of blaming vaccines for illness or other adverse effects. She tries to steer patients or parents toward a more rational approach.

“It’s a discussion about true causal relationships,” she said. “It’s talking about what you hear because it’s a good story versus what can actually be proven, through hypothesis-driven research, to be related.”

The key, Middleman added, is convincing parents and patients to embrace that logic.

“I think that when we have a vaccine that can prevent poor outcomes, we really love to take advantage of it,” she said. “If we have a preventive health strategy that we know works 85% to 95% to 100% of the time, that’s exciting for us. I’m not sure we can have that kind of success with counseling for seatbelt use or avoidance of drug use, but I know we’ve got it with vaccines.” – by Joe Green and Jennifer R. Southall

• References:
• CDC. Provider Resources for Vaccine Conversations with Parents. https://www.cdc.gov/vaccines/hcp/conversations/. Accessed April 18, 2017.
• Children’s Hospital of Philadelphia. Vaccine Education Center. http://www.chop.edu/centers-programs/vaccine-education-center. Accessed April 18, 2017.
• Edwards KM, et al. Pediatrics. 2016;doi:10.1542/peds.2016-2146.
• Freed GL, et al. Pediatrics. 2010;doi:10.1542peds.2009-1962.
• Immunization Action Coalition. http://www.immunize.org/. Accessed April 18, 2017.
• Iro MA, et al. Lancet Infect Dis. 2017;doi:10.1016/S1473-3099(17)30114-7.
• Olshinsky SJ, et al. AIMS Public Health. 2017;doi:10.3934/publichealth.2017.2.127.
• Plotkin SA, et al. N Engl J Med. 2015;doi:10.1056/NEJMp1506820.

• For more information:
• Kenneth A. Alexander, MD, PhD, can be reached at Nemours Children’s Hospital, 13535 Nemours Pkwy, Orlando, FL 32827; email: kenneth.alexander@nemours.org.
• Christoph Diasio, MD, FAAP, can be reached at Sandhills Pediatrics, 95 W. Illinois Ave., Southern Pines, NC 28387; email: cdiasio@gmail.com.
• Gary S. Marshall, MD, can be reached at the University of Louisville, 571 S. Floyd St., #321, Louisville, KY 40202; email: gary.marshall@louisville.edu.
• Amy B. Middleman, MD, MPH, can be reached at the University of Oklahoma Health Sciences Center, 1100 N. Lindsay Ave., Oklahoma City, OK 73104; email: amym@ouhsc.edu.
• Paul A. Offit, MD, can be reached at the Children’s Hospital of Philadelphia, 3401 Civic Center Blvd., Philadelphia, PA 19104; email: offit@email.chop.edu.
• Walter A. Orenstein, MD, can be reached at Emory University, 201 Dowman Dr., Atlanta, GA 30322.

Disclosures: Alexander, Diasio, Middleman, Offit and Orenstein report no relevant financial disclosures.