Out of the 67 countries surveyed, the European region was the most skeptical regarding vaccine safety, with France the most skeptical country in Europe.
Vaccines are considered by the scientific community and a majority of the public to be one of the greatest medical breakthroughs of the 20th century. Vaccines have been responsible for significantly reducing infections of many deadly diseases, and as a result, conditions such as diphtheria, polio, and tuberculosis are rarely thought about in developed countries today.
However, not everyone is convinced that vaccines are a good thing, with varying attitudes toward their safety and effectiveness.
Although people in this group are a minority, recent outbreaks of measles - a disease preventable by vaccination - demonstrates how negative attitudes toward vaccines can pose a problem for authorities.
A new study led by researchers from the Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine (LSHTM), and published in EBioMedicine, aimed to provide insights into rates of skepticism about vaccines and determine people's reasons for not trusting them.
Around 66,000 people were surveyed across 67 countries. Most individuals surveyed had positive attitudes toward immunization, but there were significant differences in the attitudes of those who had negative views.
Study noted varying vaccine attitudes worldwide
The European region had the majority of vaccine-skeptical countries, with France topping the list at 41 percent of people disagreeing that vaccines were safe - more than three times the global average of 12 percent.
Other countries with high levels of individuals concerned about the safety of vaccines included Bosnia and Herzegovina (36 percent), Russia (28 percent), Mongolia (27 percent), with Greece, Japan, and Ukraine at 25 percent.
The countries most confident in the safety of vaccines were found in the South East Asian region including Bangladesh (up to 1 percent of people with a negative view of vaccine safety), Saudi Arabia (1 percent), Argentina (1 percent), Indonesia (3 percent), and Thailand (6 percent).
As a whole, the European region had the most people - 15.8 percent - who disagreed that vaccines are safe, compared with the South East Asian region, with 4.4 percent of people disagreeing on the safety of vaccines.
In France, where the levels of people who disagreed on vaccine safety are especially high; researchers say this may be as a result of some controversies in the country over the last 20 years, including the suspected side effects of the Hepatitis B and HPV vaccines.
In other countries, some religious groups were skeptical of vaccines; however, the team found that no single religious group worldwide was more skeptical than others overall.
The investigation also found that older people - 65 and above - were generally more positive about vaccinations than people in other age groups.
Internet may escalate negative views on vaccination safety
Refusal to vaccinate may pose public health problems worldwide, such as causing diseases including polio, measles, and meningitis to make a comeback in countries where levels of infection have drastically reduced in recent decades.
Problems have also arisen with the Global Polio Eradication Initiative, leading the World Health Organization (WHO) to call for improved monitoring of vaccine confidence to prevent the problem becoming out of control and causing adverse health consequences.
The researchers note that the Internet has the potential to spread negative messages about vaccines rapidly and that authorities should not underestimate the effect this could have. They also hope that public health organizations can use this information to investigate causes for these negative attitudes and formulate responses.
"Our findings give an insight into public opinion about vaccines on an unprecedented scale. It is vital to global public health that we regularly monitor attitudes toward vaccines so that we can quickly identify countries or groups with declining confidence," says lead study author Dr. Heidi Larson from the LSHTM.
"We can then act swiftly to investigate what is driving the shift in attitudes. This gives us the best chance of preventing possible outbreaks of diseases like measles, polio, and meningitis which can cause illness, life-long disability, and death."
Dr. Heidi Larson
"It's striking that Europe stands out as the region most skeptical about vaccine safety. And, in a world where the Internet means beliefs and concerns about vaccines can be shared in an instant, we should not underestimate the influence this can have on other countries around the world," she concludes.
Larson and team also say that while the study could give indications of levels of confidence in effectiveness and safety of vaccines, it could not provide information about attitudes toward specific vaccines or the reasons for these attitudes. They hope that future surveys can provide this information and can use this study as a baseline for overall changes in attitudes.