Devexplains: Vaccine hesitancy

MANILA — The measles outbreak in the United States has reached its highest level since the disease was eliminated in the country in 2000. As of April 24, the U.S. Centers for Disease Control and Elimination announced cases were close to 700 across 22 states.

But the rising number of cases is not limited to the U.S. In Madagascar, which has not had a big measles outbreak since 2003, there have been over 118,000 infections and 1,700 deaths since the start of the outbreak in October 2018, according to a report by Save the Children. This accounts for much of the 700% increase in cases in the African region in the first quarter of 2019.

Katrina Kretsinger, a medical officer in the expanded immunization program at the World Health Organization in Geneva, Switzerland, calls the scenario “somewhat unprecedented.”

“Measles is an episodic disease, so we expect to see spikes, but it's unusual to see a spike in cases throughout the entire world,” she told Devex.

A number of cases have often been blamed on vaccine hesitancy in media reports, which the WHO defines as a “delay in acceptance or refusal of vaccines despite availability of vaccination services.” Vaccine hesitancy is regularly cited as one of the primary reasons for measles outbreaks, particularly in developed economies such as the U.S. where there’s a growing anti-vaccination movement. WHO has also identified vaccine hesitancy as one of the biggest global health threats of 2019.

But while it plays a part, experts say it’s not the entire reason for the spike in measles cases.

“WHO included hesitancy on the top 10 list because of its potential in some places to hinder the very real substantial progress the world has made in controlling vaccine-preventable diseases … [but it] is only one of many factors that contribute to under-vaccination … Vaccine hesitancy and refusal are not a complete explanation for all suboptimal coverage,” said Lisa Menning, WHO technical officer on immunization, vaccines, and biologicals.

The barriers to vaccination can vary between countries and between communities. Menning said factors such as missed opportunities, access, vaccine availability, and population movement can have an impact on low vaccination rates, and each factor’s degree of influence on vaccination rates vary per country.

While barriers to vaccination exist not just for measles, recently increased attention on this highly infectious disease reveal how these different factors have played a role in outbreaks in several countries.

In Madagascar, for example, only about 58% of infants have access or receive the vaccine against measles, leaving approximately half susceptible to the disease every year, according to Kretsinger. In Ukraine, where over 24,000 people have been infected in the first two months of 2019, previous shortages in vaccine supply have led to low vaccination rates in parts of the country, including in the worst-hit region of Lviv.

“We know that vaccination has drastically reduced illness and deaths caused by measles and many other diseases across the globe, and any resurgence of these diseases is an unacceptable step backwards,” Menning said.

Vaccine hesitancy and its impacts

Vaccine hesitancy isn’t new. Resistance to vaccines goes as far back as the 19th century, against the first vaccine developed for smallpox. Much of the concerns circled around safety and state intervention that some saw as impinging on civil liberties.

Today, similar concerns continue to exist in different parts of the world against vaccines — but aggravated by the presence of the internet and social media, where rumors and misinformation clash with facts.

In Pakistan, the government has recently suspended a polio vaccination drive after rumors of polio drops being harmful spread on social media, leaving frontline health workers vulnerable to attacks. Controversies and scandals surrounding vaccines, as in the case of the rabies vaccine in China in 2018, and the dengue vaccine in the Philippines in 2017, have also planted seeds of fear and mistrust in vaccines and state authorities amongst local communities.

In Japan, a 2013 research reported by the media that claimed harmful effects of the HPV vaccine, followed by a suspension by the government in proactively recommending the vaccine in the country’s national immunization program, have led to suspicion and decline in HPV vaccine coverage that persists today.

“Outbreaks of disease bring attention, as do other ideas and discussions that are related: fake news, social media regulation, populism,” Samantha Vanderslott, social sciences researcher at the Oxford Vaccine Group, told Devex.

But the skepticism over vaccines doesn’t always translate to low vaccination coverage, said Vanderslott, who co-authored a piece on vaccinations with Our World in Data founder Max Roser.

A study by The Vaccine Confidence Project in 2015 on vaccine perceptions across 67 countries revealed which places have the highest skepticism over vaccine safety. France topped the list, with 41% of survey respondents disagreeing that vaccines are safe.

Plotting that against World Bank data in 2016 on the share of children 12-23 months old immunized against diphtheria, pertussis, and tetanus in countries that were part of The Vaccine Confidence Project survey, Vanderslott and Roser found that despite high vaccine skepticism in France, immunization coverage of the three diseases remained high, or close to 100%. The same was true for Russia and Japan, where over 25% of survey respondents disagreed over vaccine safety.

“Even if populations are skeptical, it does not always mean that views are automatically translated into corresponding actions,” Vanderslott said.

Addressing vaccine hesitancy

The Strategic Advisory Group of Experts, or SAGE, a group of independent experts advising WHO on vaccines and immunizations, did a landscape analysis in 2013 looking at organizations working on the issue of vaccine hesitancy. It found multiple stakeholders from multilateral organizations such as United Nations agencies, academic institutions, philanthropic foundations, and government institutions working in that space.

But the analysis found that while many were starting to recognize the importance of the issue, very few were perceived to translate intentions into meaningful actions.

“Many organizations working on vaccines state in their mandates that they will work to promote the use and acceptance of vaccines among both the public and health professionals,” the SAGE analysis stated, and added that the mandates rarely specified how they will work to increase the demand of vaccines.

Most of the work done has been focused on addressing vaccine supply issues. The projects funded by the Bill & Melinda Gates Foundation, for example, are mostly focused on vaccine development, production, and safety, or health systems strengthening, according to the SAGE study.

In an interview on The Optimist, Violaine Mitchell, the Gates foundation’s deputy director for vaccine delivery, noted how the foundation is increasingly recognizing the lack of focus in addressing the demand side of vaccines and immunization.

“Have we and our partners been too supply side focused? Perhaps,” she said.

“Vaccine hesitancy or anti-vaccine sentiment is not an area we have focused on at the foundation, preferring to believe that good data, evidence and solid science speak for themselves. But increasingly, we need to draw on the lessons and growing literature of brain science and how people process information,” she said.

Anuradha Gupta, deputy CEO at Gavi, the Vaccine Alliance, a public-private partnership focused on increasing vaccination access in developing countries, shared similar views. Misinformation and rumors have a tendency to “travel much faster than good information” with the presence of social media, she said.

“Vaccine hesitancy is a challenge … and we are worried,” she told Devex. “I think that very deliberate, proactive strategies are required to really nip it in the bud because it can have a huge spillover effect.”

Michael Igoe contributed reporting to this story.