Vaccine hesitancy growing in parts of world as people doubt effectiveness, Lancet study says

Study in 'The Lancet' finds more people hesitant about trusting vaccines in countries like Pakistan, Indonesia, South Korea. France, India, Mexico show more confidence.

Representational image for a vaccine | Pixabay

New Delhi: A new study published in the medical journal The Lancet has found increasing vaccine hesitancy in many parts of the world, at a time when a Covid-19 vaccine is eagerly awaited.

The study explored the acceptance levels of vaccines and how they have changed in 149 countries between 2015 and 2019.

“Between November 2015 and December 2019, we estimate that confidence in the importance, safety, and effectiveness of vaccines fell in Afghanistan, Indonesia, Pakistan, the Philippines, and South Korea,” stated the study, conducted by researchers from the London School of Hygiene & Tropical Medicine, University of Washington, Imperial College London and the University of Antwerp.

“We found significant increases in respondents strongly disagreeing that vaccines are safe between 2015 and 2019 in six countries: Afghanistan, Azerbaijan, Indonesia, Nigeria, Pakistan, and Serbia. We find signs that confidence has improved between 2018 and 2019 in some EU member states, including Finland, France, Ireland, and Italy, with recent losses detected in Poland,” the researchers said.

Vaccines are commonly regarded as one of the most cost-effective public health measures, but in many countries across the world, there is an increase in vaccine hesitancy — experts say the success of vaccines has contributed to this, as people do not remember the severity of the diseases they prevent.

Among the most prominent in a long list of vaccine-hesitant celebrities is tennis star Novak Djokovic, who had said in an online chat in April this year: “Personally, I am opposed to vaccination and I wouldn’t want to be forced by someone to take a vaccine in order to be able to travel.”

Misinformation, exploitation for political purposes

The study is based on data from over 2,84,000 adults (over 18 years of age), who were asked if they view vaccines as important, safe, and effective. In countries like France, India, Mexico, Poland, Romania and Thailand, vaccine confidence increased across all three elements between 2015 and 2019.

“It is vital with new and emerging disease threats such as the Covid-19 pandemic that we regularly monitor public attitudes to quickly identify countries and groups with declining confidence, so we can help guide where we need to build trust to optimise uptake of new life-saving vaccines,” said Prof. Heidi Larson from the London School of Hygiene & Tropical Medicine, who led the research.

“One of the main threats to the resilience of vaccination programmes globally is the rapid and global spread of misinformation. When there is a large drop in vaccination coverage, it is often because there’s an unproven vaccine safety scare seeding doubt and distrust. Sometimes there is a genuine small risk that gets rapidly spread and amplified to appear to be a much larger risk,” Larson said.

“There are also cases where vaccine debates have been purposefully polarised, exploiting the doubting public and system weaknesses for political purposes, while waning vaccine confidence in other places may be influenced by a general distrust in government and scientific elites,” she added.

The study documented how local factors — such as the scare about the dengue vaccine dengvaxia in the Philippines in 2017 — and local anti-vaccine groups in Poland affected popular confidence in vaccines.

Japan ranked among the countries with the lowest vaccine confidence in the world. This might be linked to the human papillomavirus (HPV) vaccine safety scares that started in 2013. The Japanese ministry of health, labour and welfare decided to suspend proactive recommendation of the HPV vaccine in June 2013.

Resurgence of diseases like measles, diphtheria

Rising vaccine hesitancy all over the world has led to a resurgence in diseases that were long thought to have gone away. In 2019, the USA reported over 1,200 measles cases, the most in that country since 1992.

According to the Centres for Disease Control and Prevention (CDC), “the majority of cases were among people who were not vaccinated against measles. Measles is more likely to spread and cause outbreaks in US communities where groups of people are unvaccinated”.

India, too has seen an example of this, with an outbreak of diphtheria in Delhi in 2018, despite the fact that it is one of the oldest vaccines in India’s immunisation programme.

The Expanded Programme on Immunisation in 1978 was, in fact, launched with BCG (for tuberculosis), DPT (for diphtheria, pertussis, tetanus), and cholera vaccines.

After the Delhi diphtheria outbreak, the government of India commissioned a study on vaccine hesitancy by the Immunisation Technical Support Unit under the health ministry, in association with GAVI, the Vaccine Alliance.