As some technology companies have announced steps to combat the spread of vaccine misinformation, the American Medical Association (AMA) issued a letter to the CEOs of six of the country's leading social media and technology companies urging them to ensure their users have access to accurate, timely, scientifically-sound information on vaccines. The following letter was sent to the CEOs of Amazon, Facebook, Google, Pinterest, Twitter and YouTube.

The full text of the letter is below:

Dear CEOs of Leading Technology Companies,

At a time when vaccine-preventable diseases, particularly measles, are reemerging in the United States and threatening communities and public health, physicians across the country are troubled by reports of anti-vaccine related messages and advertisements targeting parents searching for vaccine information on your platforms. As physicians, we are concerned that the proliferation of this type of health-related misinformation will undermine sound science, further decrease vaccinations, and persuade people to make medical decisions that could spark the spread of easily preventable diseases.

With public health on the line and with social media serving as a leading source of information for the American people, we urge you to do your part to ensure that users have access to scientifically valid information on vaccinations, so they can make informed decisions about their families' health. We also urge you to make public your plans to ensure that users have access to accurate, timely, scientifically sound information on vaccines.

We applaud companies that have already taken action but encourage you to continue evaluating the impact of these policies and take further steps to address the issue as needed.

The overwhelming scientific evidence shows that vaccines are among the most effective and safest interventions to both prevent individual illness and protect public health. When immunization rates are high, people who cannot be protected directly by the vaccines are protected because they are not exposed to the disease. This includes children too young to receive vaccinations and people with medical contraindications.

The reductions we have seen in vaccination coverage threaten to erase many years of progress as nearly eliminated and preventable diseases return, resulting in illness, disability and death. In order to protect our communities' health, it is important that people be aware not just that these diseases still exist and can still debilitate and kill, but that vaccines are a safe, proven way to protect against them.

As evident from the measles outbreaks currently impacting communities in several states, when people decide not to be immunized as a matter of personal preference or misinformation, they put themselves and others at risk of disease. That is why it is extremely important that people who are searching for information about vaccination have access to accurate, evidence-based information grounded in science.