Vaccine hesitancy is reviving long dead diseases

Vaccines are perhaps the greatest public health interventions in human history. The smallpox vaccine alone is estimated to have saved 170 to 220 million lives since 1980. High immunization coverage globally has led to the elimination and suppression of many diseases; most notably eradicating both smallpox and rinderpest and significantly reducing the number of lives lost each year to infectious diseases such as polio and measles to nearly zero.

However, global immunization coverage has declined over the last decade in both adults and children, causing outbreaks of avoidable diseases across the globe.

The World Health Organization (WHO) estimates that the global vaccination coverage has dropped by 5 per cent between 2019- 2021, decreasing from 86 per cent to 81 per cent worldwide. While the reasons for the decline are complex and numerous, vaccine hesitancy is a well-known one that must be addressed.

Vaccine hesitancy can become a major barrier to disease control and elimination. For example, in Uttar Pradesh India, vaccine hesitancy and mistrust of the government became a barrier to polio elimination. For some, the mistrust came from a history of fear and neglect. Many Muslims were concerned that the vaccine contained pork, which is forbidden to ingest. Additionally, due to a history of sterility politics, some minorities feared that the government was using polio vaccines as a method of sterilization. Others did not trust that the government was sincere in delivering health efforts due to years of neglect in infrastructure and health-care needs. The sudden urgency to deliver polio vaccines was seen as suspicious.

Polio was finally eliminated in India in 2014. Although far later than some of its counterparts, it was a major victory and a critical step forward toward global eradication. Commitments to build trust and engage with stakeholders were successful. For example, resources were provided to bundle the polio vaccine with other health-care services or medications to emphasize the health element of the vaccine. Additionally, engagement with religious leaders to garner support provided the confidence to overcome religious objections.

The refusal or the unwillingness to vaccinate has led to the resurgence of deadly diseases. In 2019, there was a measles outbreak in New York State with the Centres for Disease Control confirming 242 cases of the deadly disease. The case numbers were greatest in counties among Orthodox Jewish neighborhoods that reportedly had low childhood immunization rates. Measles contagiousness is so great that a 95-per-cent immunity rate is required to prevent community spread. Similarly, in 2011, the disease broke out in a Somali community in Minnesota, where 24 cases were reported. According to the Minnesota Medical Association, prior to the outbreak members of the community had met with infamous vaccine denier and disgraced doctor Andrew Wakefield on at least three separate occasions.

California’s Disneyland was famously ground zero of a trans-continental measles outbreak in 2014.

California’s Disneyland was famously ground zero of a trans-continental measles outbreak in 2014. The disease then spread across seven U.S. states, Mexico and Canada with 147 cases reported in the U.S., 159 in Canada and one in Mexico. Subsequent research found that poor vaccination rates had played a significant role in the spread. The CDC reported that 75 per cent of Californian cases were among those who were under vaccinated. Additionally, researchers found that 76 per cent of those in this group were unvaccinated as a result of either individual beliefs or a purposeful delay in measles vaccination. The majority of the 159 cases in Canada occurred in a non-vaccinated religious community in Quebec.

In the spring and summer of 2022, Zimbabwe suffered a measles outbreak. The viral respiratory illness that  resulted in more than 2,000 cases nationwide and claimed the lives of 157 children.  Most of the victims were unvaccinated, as various religious groups had urged their followers to avoid vaccines in favour of relying on “self-proclaimed prophets.” The government of Zimbabwe is reaching out to faith and religious leaders to garner support for a vaccination campaign.

The COVID-19 pandemic has led to a spike in vaccine hesitancy – when vaccines are introduced during a time of crisis, misinformation surrounding it also spreads. One commonly cited culprit is the negative views and misinformation spread on popular social media outlets. For example, during the pandemic, many misinformation posts regarding the COVID-19 vaccine were found on Facebook. The posts focused primarily on the safety of the vaccine and mimicked the language and writing style of news outlets. This is especially concerning as it has become increasingly difficult for the public to discern valid scientific information from misinformation spread by anti-vaxxer groups.

Questioning vaccine safety is also one of the most common tactics that anti-vaccine groups use to induce fear. For example, anti-vaxxers focus on the negative reports on COVID-19 vaccines. This method is called confirmation bias.

Additionally, political polarization of vaccines also has led to public resistance and hesitancy. There has been a decline of the public’s trust in the expertise of public health authorities and government figures. Politicization of the vaccine was evident especially in the United States, where Democrats were more likely to take the threat of COVID-19 seriously while the disease was more likely to be downplayed by Republicans. This led to lower vaccination rates among Republican voters, and a higher likelihood of exhibiting risky behaviours such as not wearing masks while indoors.

So, what should we do about the surge of diseases because of vaccine hesitancy?

In the immediate future, medical, nursing and pharmacy schools should train their students on managing/treating illnesses that were previously considered rare. If vaccine hesitancy continues to be an obstacle in public health, then our health-care professionals need to be prepared to manage these diseases.

Misinformation surrounding vaccines and public health has become a powerful tool to further political or personal agendas.

Misinformation surrounding vaccines and public health has become a powerful tool to further political or personal agendas. As such, it has incentivized some to spread false information. To combat this, policies need to be put into place to offer strong protection against whistleblowers who speak out against falsehoods. Notably, Canada was recently ranked last when it comes to protecting whistleblowers, as the current law only protects public servants and not private citizens. Strengthening these laws will ensure that those working to provide correct information to the public will not face repercussions.

Given the widespread impact of misinformation, and how everyone is susceptible to it, educational institutes should consider mandating courses on media literacy. Similarly, universities should consider making communication an integral part of the curriculum for science students. In doing so, graduating scientists will understand how to better communicate their findings and complex science topics in a way that the wider public can understand and better appreciate.

While vaccine misinformation is a problem that will never be completely eradicated, we can take steps to ensure that the harm it poses toward public health is minimized, and that long dead or rare diseases remain that way.