On Saturday, the world recognized World AIDS Day. Since it was first recognized as a cause of death in the United States, the CDC reports that 507,351 people have died from HIV disease. Worldwide, over 35 million people have died of HIV.

But, there is cause for hope.

From 2010 to 2015 the estimated rate of HIV infections in the United States declined by eight percent. More telling, during nearly the same period, 2011 to 2015, the number of new HIV diagnoses fell by five percent.

Paramount to this progress has been the research and development of new and cutting-edge treatments. Since the first antiretroviral drive, AZT, was released in 1987, the medical community has responded to this threat with incredible speed. Today, treatments can help individuals living with HIV suppress viral levels to the point that the virus is undetectable and they have “effectively no risk of transmitting HIV.” Similarly, medicines are available for individuals at risk of contracting HIV which can reduce the risk of HIV transmission by up to 90 percent, according to the CDC.

However, this preventative treatment is not as readily available in other developed nations, due to their socialized healthcare systems.

In the United Kingdom, this preventative medicine is heavily regulated and controlled by the National Health Service due to the country’s single-payer system. In single-payer systems, governments have only two options to control the cost of care: deny or ration it. When it comes to this HIV prevention medication, the NHS has done both.

Though the medication was available in the United States in 2012, the U.K. health system did not begin prescribing it until 2016, after losing a court battle in which they argued they should not have to cover the medication. In the U.K., this delayed access resulted in numerous HIV infections which will now cost the health system even more in long term care and associated costs. In fact, even as the U.K. system is now required to prescribe the medication, the health system has capped access to the medication, here again displaying the downfalls of socialized systems.

In the U.K., rather than increase competition and choice for patients, their system can only restrict care. The end result: patients and public health suffers.

We have vocally opposed policies in this country that we believe threaten our market-based healthcare system, while also calling out drivers of cost that increase the burden on families all across the United States.

Recently, U.S. Department of Health and Human Services Secretary Alex Azar proposed another such policy, which would use the prices in countries with socialized medicine to set prices in our Medicare Part B program, creating a de facto price cap. This plan will not only have immediate negative consequences in terms of access to cutting edge medicine, but will curtail research and development of new cures for numerous diseases, creating long-term consequences for our collective, global health.

Just as in the United Kingdom, which is one country the policy would use as a reference, these countries can only deny or ration care to control costs. Bringing those same policies to the U.S. is a mistake and would dramatically curtail research and development into new cures and medications. It’s why we joined with over 50 other groups and activists to publicly request that Sec. Azar oppose this proposal and preserve America’s innovative environment.

Instead of further skewing or capping our healthcare market, leadership in Washington should look for how to increase competition and transparency to create accountability and bring down prices.

Today’s medications can not only dramatically reduce the rate of new HIV infections but have also improved the quality of life for millions living with HIV across the world. We must protect this progress and this innovation. Sec. Azar’s proposal does the opposite, and World AIDS Day reminds us of why it’s vital he reject that policy.