“Disruption of immunization services, even for brief periods, will result in increased numbers of susceptible individuals and raise the likelihood of outbreak-prone vaccine preventable diseases”

– World Health Organization, Guiding principles for immunization activities
during the COVID-19 pandemic

INTRODUCTION

May 8, 2020 marked the 40^th anniversary of the smallpox eradication. However, this historical achievement has been tempered as there is a growing concern that global societal disruptions and lockdowns have been affecting the immunization rates in both developing and developed countries. In an article titled ‘A rise in deaths from preventable diseases must not be part of COVID-19’s legacy’, Dr. Edward Parker, a research fellow at the Vaccine Centre at the London School of Hygiene & Tropical Medicine, warns that the incidence of vaccine preventable diseases will spike as immunization programs are suspended.

Vaccine preventable disease outbreaks have followed crises in the past. After the Ebola outbreak in the Democratic Republic of Congo, an eruption of measles cases claimed more than twice as many deaths as Ebola (Parker, 2020). These crises disrupt vaccine delivery and distribution, shifting focus to more immediate health concerns. Competing agendas and the spread of misinformation further undermines efforts to maintain routine vaccination schedules.

Vaccines are often described as “victims of their own success” (Iwasaki & Omer, 2020; Nadeem, 2018). They are so effective at preventing disease, few people remember the devastation and suffering that diseases such as measles and polio can cause (Iwasaki & Omer, 2020). This breeds complacency as many people do not prioritize vaccination while others view potential vaccine side effects as a more concerning issue than the disease itself (Nadeem, 2018). However, even when facing the current threat of COVID-19, a high percentage of the population is resistant to vaccination despite the constant coverage of the dangers associated with the disease.

In this blog post, we will explore the following:

• A (Brief) History of Vaccines 
• Why is There a Growing Vaccine Hesitancy Movement?
• The Implications of COVID-19 on Vaccination Efforts
• Public Health’s Role in Addressing Anti-vaccination Sentiments

A (Brief) History of Vaccines

The process of vaccination involves introducing an inactive or weakened version of a microorganism into the body to stimulate the body’s own immune system to generate antibodies. This allows the person to fight the disease when exposed again. 

Examples of using inoculation to protect against smallpox are described in Chinese and Indian texts dating back to the 1500s (Boylston, 2012). Edward Jenner is credited with developing the first scientific process of vaccination to smallpox in 1798 after he exposed an 8-year-old boy to fresh cowpox lesions and documented his subsequent immunity to the disease (Iwasaki & Omer, 2020; Riedel, 2005). Jenner coined the term vaccination from the Latin term for cow, vacca (Riedel, 2005).

The next major development in vaccine science came in the mid-19th century when Louis Pasteur developed the process of creating vaccines in laboratories. This eventually led to the development of typhoid, cholera, and plague vaccines in the 1880s. Throughout the 20th century, vaccines were developed for a wide range of common diseases. In 1986, the Hepatitis B vaccine became the first genetically engineered vaccine (Iwasaki & Omer, 2020). 

The highly publicized mRNA vaccines for COVID-19 represent the latest leap forward, not only providing hope of a way out of the current pandemic, but also a potential method of fighting other devastating diseases such as malaria and tuberculosis (Ball, 2021).

Vaccinations are heralded as one of the greatest achievements in public health and are estimated to save 2-3 million lives annually (WHO, 2021). Notable success stories include: 

• the eradication of smallpox in 1980 which had claimed 300 million lives just in the 20th century 
• the significant reduction of measles mortality from half a million deaths to less than a thousand annually
• reducing the number of people infected with polio from 350,000 annually in the 1980s by 99.9% 

Why is There a Growing Vaccine Hesitancy Movement?

The WHO defines vaccine hesitancy as the reluctance or refusal to vaccinate despite the availability of vaccines (WHO, 2021). Vaccine hesitancy is complex with multiple influencing factors including:

• parental factors such as apathy, disorganization, and strong anti-vaccine beliefs
• health care system factors such as appointment availability, distance, and inconvenience
• the media and its contribution to misinformation and fear mongering (Nadeem, 2018).

Anti-vaccine sentiments are not new. Jenner was ridiculed by many of his peers after publishing his method of smallpox vaccination (Riedel, 2005). Nowadays, vaccine misinformation spreads rapidly across the globe through social media and other online forums, presenting personal anecdotes and rumours as equal to rigorous scientific research (Nadeem, 2018).

Vaccine hesitancy has multiple public health consequences and the WHO has declared it as one of the top 10 threats to global health (WHO, 2021). Polio was all but eradicated in the early 2000s, but vaccine misinformation in Nigeria regarding the oral polio vaccine brought wide-spread boycotts. Polio cases sharply increased not only in Nigeria, but also spread to previously polio-free neighbours (Parker, 2020).

The resurgence of vaccine preventable diseases is not limited to developing nations. Growing vaccination hesitancy across the United States and Europe has played a major role in decreasing vaccination rates, leaving areas vulnerable to measles and other vaccine preventable diseases (Gardner, Dong, Khan, & Sarkar, 2020; Parker, 2020). In 2019, the United Kingdom lost its measles-free status and the United States reported 1282 measles cases, the highest number since the 1990’s (Parker, 2020).

COVID-19 vaccination efforts have also been plagued by anti-vaccination rhetoric. The rapid schedule of the vaccine’s development has further stimulated scepticism of its efficacy and safety. The resulting sub-optimal uptake of COVID-19 vaccines in many regions of the world has left millions at risk of contracting and spreading the disease while delaying the long awaited ‘return to normal.’

The Implications of COVID-19 on Vaccination Efforts

Millions of children missed routine childhood vaccines in 2020 due to COVID-19 disruptions, particularly in countries with the greatest burden of vaccine preventable disease (Causey et al., 2021). Door-to-door outreach and mass vaccination campaigns utilized by many low- and middle-income countries were in direct contradiction to COVID-19 social distancing guidelines (Parker, 2020). The WHO recommended the temporary suspension of vaccine efforts except in areas with active vaccine preventable disease outbreaks (WHO, 2020).

Parents have also chosen to delay or skip routine vaccinations during the crisis due to safety concerns about attending routine medical care. Further, anti-vaccination groups have jumped on the scientific community’s lack of initial understanding about COVID-19 to further undermine all vaccine science and discourage parents from vaccinating their children (Vanderpool, Gaysynsky, & Chou, 2020). 

As COVID-19 vaccines roll out, resources have been diverted from routine vaccine production, supply, and delivery. Children, who have largely been considered safe from the serious complications of COVID-19, are now being placed at risk of vaccine-preventable diseases (Parker, 2020).

Public Health’s Role in Addressing Anti-vaccination Sentiments

As the COVID-19 pandemic has highlighted, effective communication remains a major public health challenge. Vaccine study results are written to scientific audiences and are often incomprehensible to the general population (Germani & Biller-Andorno, 2021). By contrast, anti-vaccine materials are more engaging, readable, and easily shared. Distrust in science and government further fuels anti-vaccine arguments, with many sources purporting cover-ups regarding effectiveness and dangers of vaccines (Germani & Biller-Andorno, 2021; Nadeem, 2018). 

Healthcare workers play a large role in vaccine uptake with the attitude of primary care health workers largely influencing parental vaccination decisions. Health professionals can empower parents to make informed health decisions by promoting accurate vaccine information and encouraging open dialogue with their patients and the wider community (Nadeem, 2018).

However, medical professionals are not immune to anti-vaccine messaging and can be swayed by the negative portrayal of vaccines in the media. Healthcare workers and students are not as exposed to vaccine preventable diseases as they had been in previous generations, which can lead them to prioritize other health concerns (Nadeem, 2018).

The COVID-19 emergency has triggered anti-vaccination groups, many of which are using the crisis to further erode faith in science. However, the pandemic also poses an opportunity for public health professionals to engage with the general public and stress the need for reinforcing health literacy. The current emphasis on COVID-19 immunization efforts can facilitate trialling novel approaches to countering misinformation including:

• engaging with former conspiracy theorists to share insight into anti-science groups and share evidence-based information with their followers
• mobilizing pro-vaccine influencers to counter anti-vaccine rhetoric
• developing methods to identify credible sites that share  accurate information
• proactive monitoring of social media to ensure misinformation is flagged or hidden (Vanderpool et al., 2020)

Key Takeaways

Vaccines are one of medicine’s greatest achievements and are credited with saving millions of lives every year. While successes such as smallpox eradication should rightfully be celebrated, it is important to highlight that:

• gains in childhood mortality around the world are under threat from growing vaccine hesitancy as anti-vaccination misinformation can now spread quickly to all parts of the globe
• disruptions to routine care through the COVID-19 pandemic have  further hindered vaccination efforts
• anti-vaccine groups have leapt at the opportunity to erode confidence in science by spreading misinformation about COVID-19 and the global vaccination roll-out
• healthcare professionals play an important role in influencing vaccination decisions and public health decision makers can use opportunities presented by the pandemic to strengthen methods of countering misinformation.

It is the role of all working in public health to remain vigilant regarding vaccine preventable diseases. As Dr. Parker states, “without systematic efforts to maintain immunisation programmes, [COVID-19’s] legacy could include a disastrous surge in childhood deaths.”

Written by: Malissa Underwood, BSN, MPH