The people who are hesitant to get the Covid-19 vaccines and the anti-vaxxers have something in common. They had been vaccinated for at least a preventable disease in their lives. They probably did not realize that the reason why they still live up to now is the vaccine they once were inoculated with. We can credit their lives and that of their children to the vaccines that triggered their immune system to have an army and armory of antibodies that protect against present and future attacks of unseen enemies on Earth. They may still get sick but the vaccines have pre-set the memory of their immune system to have the infection under control.
We, including the vaccine hesitant and the anti-vaxxers, should be thankful to the science of vaccinology, the very same science or even an improved version of the science that brought the vaccines against the novel coronavirus causing this pandemic. Science as an evolving discipline shall continue to improve upon what it already knows in the discovery of what may still be out there to understand and use in an ever-dynamic universe.
Vaccines in retrospect
Vaccinology, a 225-year-old science, historically includes basic science, immunogens, the host immune response, delivery strategies and technologies, manufacturing and clinical evaluation. From the story of the West in 1796, a British Doctor Edward Jenner inoculated a 13-year-old boy with vaccinia virus and demonstrated immunity to small pox. Two years after, the vaccine against smallpox was developed. For that, Edward Jenner was regarded to have founded vaccinology. But earlier than that, Buddhist monks drank snake venom to confer immunity to snake bites. Also practiced was the smearing of a skin tear with cowpox, called variolation, to confer immunity to small pox.
Other scientists followed the lead. Louis Pasteur led to the development of cholera vaccine (1897) and anthrax vaccine (1904) for humans. Plaque vaccine was also invented in the late 19th century and between 1890 and 1950, bacterial vaccine development proliferated, including Bacillis-Calmette-Guerin (BCG), which is still being used today to prevent the then killer pulmonary tuberculosis. Alexander Glenny gave us the inactive tetanus toxin, which is the same technology that led to the development of the vaccine against diphtheria in 1926 and against pertussis licensed in 1948. This led to what most of us got as DPT vaccine.
Between 1950 and 1985, the viral tissue culture methods led to the advent of the polio vaccine, which eradicated the disease in many regions around the world after mass polio immunization. Thanks to Jonas Salk and Albert Sabin for these.
There had been recent development with the application of molecular genetics and increased insights into immunology, microbiology and genomics. Vaccines are now staging a good fight against dreaded diseases like hepatitis, influenza, pneumonia, human papilloma virus, cytomegalovirus, chicken pox, dengue fever, HIV, and more. And the list is not limited to communicable diseases as vaccines may soon be available against allergies, autoimmune diseases and addictions.
Upon the discovery of the novel SARS-CoV-2, the world of science engaged to provide for the solution based on the lessons of the past, resources and expertise of the present and the motivation to save the future.
Understanding hesitancy
Vaccine hesitancy refers to the delay in acceptance or refusal of vaccination, and the unwillingness to receive vaccines, when vaccination services are available and accessible. It covers a small percentage of the population but its harmful effects are most likely to be more pronounced during the pandemic and in the age of social media where cognitive biases are exaggerated with its Dunning-Kruger, ripple and eventually bandwagon effects. Vaccine hesitancy is pervasive, maybe misinformed, and surely contagious and is not limited to Covid-19 vaccination. Vaccine hesitancy is complex and context specific. The freedom inherent in modern humanity is both a shield to protect and a privilege to invoke regardless of personal or social gains or harms.
The vaccine hesitancy continuum proposed by SAGE Working Group starts with an outright refusal of all vaccines where blindly nothing is acceptable at all—non-negotiable. This is followed by some awakening moment when one “refuses but unsure.” This is followed by “accept some, delay, refuse some” stage when reluctance is balanced with some opportunity to get more enlightenment. This expands to “accept but unsure” which may be passive willingness but with reservation. Until it reaches the level where one “accepts all.”
Vaccine hesitancy may be present in situations where vaccine uptake is low because of systems failure (like sock-outs, limited availability, curtailment of vaccine services), and in which case hesitancy is not the main reason for the presence of unvaccinated and under-vaccinated population. Studies, however, show that when rates of hesitancy are high, levels of demands are low, but low rates of hesitancy do not necessarily mean that demand will be high. There is indeed a need to develop specific strategies beyond those aimed at addressing hesitancy. While some areas in the country are flooded by the eager recipients of the vaccines, there remains to be areas where people are patiently waiting for its availability.
Seeing hesitancy through the C’s
The SAGE Working Group proposed the Hesitancy Three C’s Model (2015) of vaccine hesitancy to include confidence, complacency, and convenience. Confidence is defined as trust in the effectiveness and safety of the vaccines, the system that delivers them including the health professionals and the motivation of the policy-makers who decide on the needed vaccines.
Complacency exists where perceived risks of vaccine-preventable diseases are low and vaccination is not deemed a necessary preventive action. Self-efficacy, the self-perceived or real ability of an individual to take action to be vaccinated, also influences the degree to which complacency determines hesitancy.
Convenience is a significant factor when physical availability, affordability, and willingness to pay, geographical accessibility, ability to understand and appeal of the immunization services affect the uptake. The quality of the real or perceived service and the degree to which the vaccines are delivered in a time and place and in cultural contexts that is convenient and comfortable also affect the decision.
The recent SWS survey indicates that 45 percent of Filipinos are now willing to be inoculated, a 13 percent jump from the previous month. Some 36 percent of the 45 percent said that “they will surely get it” while 9 percent said that “they will probably get it.” This is way far from the herd immunity that health authorities set to target ideally at 94 percent of the population to interrupt the chain of transmission.
Of the three C’s above, confidence seems to be an issue. Variables in the efficacy rates, questions of safety amplified by the news about serious side effects, and the polarized society due to political divisiveness may have all contributed to this.
Other C’s may emerge, as we understand the complex nature of hesitancy, and now include constraints, calculations and collective responsibility.
There are contextual influences arising due to historical, socio-cultural, environmental, health system, economic or political factors. The Dengvaxia controversy which remains unresolved, the uneven distribution of vaccines throughout the archipelago, and the country of origin of the major vaccine supply, which many Filipinos dislike, have all been factors to affect the public’s appetite to savor the value of the vaccine. The individual influences arising from personal perception of the vaccine or influence of the social and peer environment is surely affected specially in social media where the less competent have become more confident and seem to have more time to confirm their biases and create a bandwagon effect among like-minded community of vaccine-hesitant and antivaxxers. This is aggravated by the traditional media that, in the spirit of balanced perspective, give the detractors of the vaccine generous airtime.
In response to this, the Vaccine Solidarity Movement was born as a unified alliance of medical and health professionals and organizations, esteemed scientists and researchers and multi-disciplinary experts to make available reliable and valid information that will guide the public in making the most important decision of their lives in this time—to get vaccinated.