Anti-vax movement among top 10 global health threats for 2019, World Health Organization says

The anti-vaccination movement made the list of the World Health Organization's top threats to global health in 2019. The organization said some people's reluctance or refusal to vaccinate threatens to reverse progress made against a host of preventable diseases.

"Vaccination is one of the most cost-effective ways of avoiding disease — it currently prevents 2-3 million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved," WHO said in a statement.

The effects of what WHO called "vaccine hesitancy" are already significant. For example, cases of measles have surged 30 percent worldwide in recent years, despite an effective vaccine that can prevent it. WHO noted that some countries that were close to eliminating the disease have seen a resurgence. 

The reasons why some people choose not to vaccinate are complex, WHO said, citing "complacency, inconvenience in accessing vaccines, and lack of confidence" as the main factors. Even though decades of medical research has proven vaccines are both safe and effective, skeptics continue to spread misinformation online.

In the United States, approximately 100,000 young children have not been vaccinated against any of the 14 potentially serious diseases for which vaccines are recommended, according to a report released last year by the Centers for Disease Control and Prevention. While most American children are routinely vaccinated, the number who have received no vaccines by the age of 2 is slowly creeping up.

Worldwide, WHO plans to ramp up its work in 2019 to eliminate cervical cancer by increasing use of the HPV vaccine. The organization also hopes this is the year the transmission of poliovirus is finally stopped in its last two holdouts, Afghanistan and Pakistan. Last year, fewer than 30 cases of polio were reported in both countries.

WHO also warns of the dangers of influenza — a century after the 1918 flu pandemic killed millions of people around the globe. "The world will face another influenza pandemic — the only thing we don't know is when it will hit and how severe it will be," the report states. The authors stress the importance of getting a flu shot each year for the best protection against the virus.

Another disease that made WHO's list of global health threats is Ebola, which caused two separate outbreaks in the Democratic Republic of the Congo in 2018.

While much of WHO's list focused on infectious disease, it also included the increasing prevalence of noncommunicable diseases like diabetes, cancer and heart disease. These types of conditions, linked to lifestyle factors like obesity, alcohol and tobacco use, are "collectively responsible for over 70% of all deaths worldwide, or 41 million people," the report said.

Climate change, pollution and health

A different type of health threat is posed by climate change and air pollution, which also made the list of biggest concerns.

Globally, nine out of 10 people breathe polluted air every day. Pollutants in the air can penetrate respiratory and circulatory systems, damaging the lungs, heart and brain and causing an estimated 7 million premature deaths every year from diseases such as cancer, stroke, heart and lung disease.

Additionally, WHO predicts that between 2030 and 2050 climate change is expected to cause 250,000 additional deaths per year, from malnutrition, malaria, diarrhea and heat stress.

The report warns that even if all the commitments made by countries for the Paris Agreement are met, the world is still on a course to warm by more than 3°C this century. Even half that amount of warming would be more than enough to cause widespread risks to health, livelihoods, and food security, according to U.N. climate experts.