|Policy Guidelines for the Development and Promotion of Open Access, UNESCO|
Your options are to drive to a medical school library and copy it... or contact one of the authors and "beg" them to send you a copy (for free)... or buy it from the publisher for $15 to as much as $100 per article.
For those belonging to other scientific disciplines like physics, many of the research articles are available for free as part of the Open Access movement. If you look at the graph, you can see that Clinical Medicine is quite pathetic when it comes free literature.
There is some movement to make medical papers more available, especially when the National Institute of Health in 2008 mandated that any research funded through its grants must be made freely available to the public one year after publication (given it was paid for with taxpayer money). Also, the Gates Foundation has similarly mandated by 2017 that any research funded through its grants must be made publicly available immediately. However, more needs to be done...
As long as medical schools and healthcare organizations are willing to pay big bucks to purchase these expensive journals, I am doubtful that much else will become free for anybody to read.
Of course, there has also been research in how to make scientific publications available for free which you can read more about here.