Vaccine hesitancy is a global public health threat. Are we doing enough about it?

The recent resurgence in measles is testament to why we need to vaccinate against misconceptions

Vaccination image
© istock.com/Pornpak Khunatorn

Despite the overwhelming volume of evidence on the benefits of immunization, widespread misconceptions and mistrust of information about vaccine efficacy and safety remain. Concerns about vaccine safety now represent a complex and rapidly changing problem globally. The situation is paradoxically complicated by past vaccine successes, as neither patients nor physicians have experienced — or appreciate — the severe morbidity and mortality associated with vaccine-preventable diseases. As a result, we are observing a slowing in vaccine uptake leading to serious outbreaks of infectious diseases and some countries even losing their eradication status, according to a 2019 report by the European Regional Verification Commission for Measles and Rubella Elimination (RVC).

Recently, the College of Physicians of Madrid disqualified a doctor for making public declarations linking vaccines with autism and explicitly recommending children or people with autism and pregnant women not to vaccinate. Her claims were staggering considering the drive for clinicians to use evidence-based practice and the evidence available supporting the use of vaccines.

Throughout history and around the world, we have seen examples of the impact that a drop in vaccination rates has on public health. Looking at the vaccine against pertussis as an example:

  • In 1974, vaccination rate decreased in Great Britain. This was followed by an epidemic of more than 100,000 cases of pertussis and 36 deaths by 1978.
  • In Sweden, the annual incidence rate of pertussis per 100,000 children of 0-6 years of age increased from 700 cases in 1981 to 3,200 in 1985.
  • In Japan, after vaccination rates plummeted from 70 percent to 20-40 percent, a jump of over 3000 percent in pertussis cases was observed between 1974 and 1979.

Now, it seems history is repeating itself with the recent outbreaks of measles around the world.

The resurging measles epidemic

Between 2000 and 2017, measles vaccination prevented an estimated 21.1 million deaths, according to the World Health Organization (WHO). But now, the number of reported measles cases around the world is on the rise.

The numbers are overwhelming: in 2018, there were more than 80,000 suspected cases of measles reported across 53 countries within WHO European Regions. This was the highest figure in 20 years, according to an article in The Lancet, but has already been exceeded in 2019, with a number of reported cases in the first trimester 300 percent higher compared to the same period in 2018, and a cases count of over 90,000 as of August 2019.

Increases in the number of cases have also been seen in countries with high overall vaccination coverage, including the United States of America, Israel, Thailand and Tunisia, according to the WHO.

The measles vaccine has repeatedly been shown to be safe and effective. It has been in use for over 50 years, first as a standalone vaccine, then within the MMR vaccine, covering measles, mumps and rubella. It is relatively inexpensive (the cost for immunizing a child against measles is approximately $1). Therefore, it is worrying that significant outbreaks of this disease continue occurring around the world.

Why is vaccine hesitancy a global public health threat?

Vaccine safety issues have progressively taken on a life of their own outside the scientific world and have been unjustifiably linked to a number of diseases.

This public mistrust is thought to be a major factor in the drop in measles vaccination rates. However, the barriers to vaccination are numerous and diverse. The list includes the following contributing factors, cited by the European Centre for Disease Prevention and Control and a recent article in the British Medical Journal.

  • Complacency
  • Inconvenience in accessing vaccines
  • Lack of confidence
  • Lack of access to vaccines
  • Language or literacy difficulties
  • Lack of knowledge about the significant health consequences of “childhood diseases” and “the flu” and the proven benefits and safety of vaccination
  • Religious beliefs

Additionally, guidelines recommend two doses of the MMR vaccine to ensure the individual’s immunity, but only 67 percent of children globally have received the recommended second dose, according to 2019 WHO data.

Beyond protecting individuals, vaccination is a public health issue. Herd immunity happens when a high percentage of the population (95 percent) is immune against a disease, making it hard for viruses to be transmitted as there are very few potential hosts. This herd immunity prevents outbreaks and gives protection to vulnerable people such as newborn babies, the elderly and those too sick to be vaccinated.

There is evidence indicating that missed opportunities to immunize constitute barriers to achieving the coverage goals we expect as a society. More than that, there is evidence that promoting healthy vaccination behavior benefits society: immunization campaigns at the beginning of the 20th century in the US had the following impacts:

  • The number of children killed by pertussis decreased from 8,000 per year to fewer than 20.
  • The number of children with sequelae of poliomyelitis decreased from 15,000 per year to 0.
  • The number of people killed by measles decreased from 3,000 per year to 0.
  • The number of children with severe birth defects caused by rubella decreased from 20,000 per year to 0.
  • The number of people with meningitis and bloodstream infections caused by Haemophilus influenzae type B decreased from 25,000 per year to fewer than 100.

Vaccines are not only effective, they are needed. In a recent WHO study on an experimental Ebola vaccine, among the 5,837 people who received the vaccine, no Ebola cases were recorded 10 days or more after vaccination. In comparison, there were 23 cases 10 days or more after vaccination among those who did not receive the vaccine.The fact that vaccination can be so effective in the middle of an outbreak reinforces the need to encourage people to vaccinate.

What can we, as experts in the health industry, do about this crisis?

Vaccination against these misconceptions is the only way to address vaccine hesitancy. As providers of health information, our obligation is to reduce the barriers to providing effective vaccination, at least those related to concerns about the efficacy and safety of vaccines. This involves providing medical and scientific information at the right place and time, in the right format, in the right language to health workers, policymakers and patients.

Holistic hubs of information like ClinicalKey, with its extensive database of openly available scientific articles from top journal titles can enable healthcare professionals to provide academically and scientifically-backed information to those who require it.

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