Some deadly diseases are making a comeback, decades after scientists had largely eliminated them with vaccines. Recent outbreaks of the oldest vaccine-preventable diseases such as measles, pertussis, diphtheria and polio in developed and developing countries call for global vigilance on immunisation programmes. Public health officials attribute recent outbreaks in developed countries to vaccine hesitancy, a phenomenon as old as vaccines themselves. The World Health Organisation defines vaccine hesitancy as “delay in acceptance or refusal of vaccines despite availability of vaccination services” and suggests, “It is influenced by factors such as complacency, convenience and confidence.”

Vaccine hesitancy – also referred to as vaccine refusal, anxiety, social resistance and more – is “complex and context specific varying across time, place and vaccines,” according to WHO. Vaccines save millions of lives, and yet researchers point out that vaccine hesitancy is a dangerous global trend – in populous emerging economies like India and China as well as advanced economies including the United States and Europe. Concerns about vaccine safety are growing in countries such as Russia, Japan, France, Italy, Greece, Vietnam, and Saudi Arabia.

With scientific breakthrough discoveries in vaccine-preventable diseases since the late 18th century, public health officials worldwide endorse immunisation as the single preventive and cost-effective health intervention. The international community promotes vaccinations as an essential factor for ensuring health equity, especially in low- and middle-income countries.

In 1977, the WHO launched the Expanded Programme on Immunisation to ensure universal equitable access for children and mothers to vaccines against six diseases: diphtheria, pertussis, tetanus, poliomyelitis, measles and tuberculosis. To advance research on new vaccines and improve immunisation coverage, the Global Alliance for Vaccines and Immunisation, or GAVI, was created in 2000, bringing together public and private sectors for global immunisation access.

In 2012, the Global Vaccine Action Plan was endorsed by 194 member states of the World Health Assembly with the aim of preventing millions of deaths by 2020.Today, researchers have developed vaccines to prevent many diseases, and the GAVI alliance is committed to international support for research on developing new vaccines for other infectious diseases.

Prevention: Vaccination rates for the three doses of combined DTP3 vaccine vary widely with world coverage at about 85 percent. Source: WHO, UNICEF and the World Bank

Lack of trust

Immunisation has proven to be cost-effective with immunisation of 116.2 million infants with three doses of combined DTP3 vaccine for diphtheria, pertussis and tetanus in 2017. Despite these efforts, global vaccination coverage remains at 85% , with 19.9 million infants not receiving three doses of the vaccine that year. Improvements in global immunization coverage are required to prevent vaccine-preventable deaths of children worldwide every year.

A common reason given for vaccine hesitancy is lack of trust among communities and parents for immunisation campaigns. Less trust in government, vaccine researchers, the vaccine industry, and fear around safety and efficacy of vaccines are among the factors driving parents’ decisions to delay or refuse vaccinations for their children.

With the rise of the anti-vaccination movement in the West, countries such as United States have seen surge in parents resisting and delaying vaccines for their children despite mandatory immunisation regulations by schools and the government. Countries like India also report hesitancy in some parts even without organised anti-vaccination movements. Despite eradication of smallpox and polio, India reports other diseases long prevented by vaccines such as diphtheria in parts of the country. After outbreaks of diphtheria in 2018, the Ministry of Health and Family Welfare in collaboration with Bill and Melinda Gates Foundation commissioned a study on vaccine hesitancy in India.

There are some similarities in factors driving vaccine refusal in western countries and developing countries. Fear of risks associated with vaccines among parents and adverse reactions for children following immunisation are common factors associated with vaccine hesitancy. A complex web of historical, political, sociocultural and economic factors including everyday community social networking processes shape parents’ choices not to vaccinate their children in developing countries, especially among the poor and socially marginalised populations.

The case in India

Influenced by religious suspicions and rumors, mass community resistance surfaced in India’s northern region of Uttar Pradesh and Bihar states during polio campaigns before the country eradicated the disease in 2014 . Similar patterns of resistance to the polio vaccine emerged in parts of Nigeria and Pakistan. Major rumors included suggestions that the polio vaccine caused infertility/impotency, especially among Muslim boys and that vaccination programmes were part of a larger government agenda to reduce high birthrates in the Muslim community. Other fears centered on the possibility of post-vaccination illness or deaths and the vaccines containing undesirable constituents forbidden in Islam such as pig fat or meat.

In developing countries, trust in vaccination programmes is tied to building community trust in the government and public health-care delivery system. The inadequacy and inequities of the public health system – including poverty, disparity in infant mortality rates or life expectancy, and shortages of trained providers can significantly reduce community trust. The Indian public health system still struggles with inadequate health infrastructures, shortages of health providers, constraints for health-care workers reaching remote areas, vaccine shortages, and other issues regarding quality and logistics of vaccine management. Despite government efforts, low vaccination coverage rates remain a persistent problem in many pockets throughout India.

This lack of trust in government and the health-care delivery system resulted in resistance to polio vaccine among Muslim population in northern regions of Uttar Pradesh in India. Long- term deprivation and neglect of basic government amenities including education, health and other services among the Muslim population aroused suspicions over government efforts targeting one disease – polio. Neglect of care for other diseases and urgent health problems, unresponsive and ineffective primary health care services, and generally dismal living conditions of marginalised populations led to resistance against the campaign.

With the measles and rubella campaign underway in India, reports of parents refusing to vaccinate their children have surfaced. One major objection is lack of parental consent before the vaccine is given to children at schools. The courts supported parents and stalled the campaign in the capital city of Delhi. There were also reports of more than 70 schools in Mumbai not supporting the measles-vaccination programme based on parent objections. Thus, the use of force or coercion in administering vaccinations to children contributed to the growing resistance among parents toward specific single-disease mass-immunization programmes.

Interpretation of common side effects after immunization also shapes community perceptions. Post-immunization adverse events, especially the rare occurrence of a child’s death, trigger apprehensions about vaccine quality and safety, shared by poor and wealthy parents alike. Addressing the unmet need of information on vaccines and treatment of common side effects among parents is fundamental for building trust. News reports on the rare post-vaccination side effects and deaths influence current measles and rubella campaigns much like the polio-eradication programme in the past.

In 2017, World Health Organisation reported about 110,000 deaths from measles worldwide, most children under the age of five. The United States reported 372 cases of measles in 2018, with no deaths, while India reported about 60,000 cases. Vaccine-hesitant parents in developing and developed countries alike are labeled as ignorant, backward, selfish, shameful and more. Yet little attention is directed to the various sociocultural, economic and political factors, and many health-system gaps shaping community and parental choices on vaccinations. Building trust in the health system takes time and requires catering to unmet socioeconomic and health needs of communities as well as seeking parental consent and addressing the many concerns around vaccines. Reducing inequities is essential for building trust in both emerging and advanced economies.

This article first appeared on Yale Global Online.