I/DW have held VGHCX/VGHAX for close to two decades and have been pleased with our overall results.
While this question comes up in many forums I'll just comment on why we keep it.
For us, it was a consistent "winner" over many years and worked out for the type of investing we do (long term - don't concentrate on short-term flux).
The expense ratio of VGHAX is 84% less than similar sector funds.
It does not only invest in Parma, but also medical supply companies, and research firms. Additionally, it adds a mix of both domestic and foreign held companies.
As far as possible changes to U.S. public health care laws? We don't look at it in a negative manner, at all. Remember (and speaking for VG's HC funds only), they do represent foreign companies - and foreign public health care "systems" - most unlike the current U.S. variety.
We also feel that if HC changes in the Parma area (e.g. sourcing drugs less expensively from another country), the expansion of drugs to those who cannot afford them will radically increase. What is lost in quality/high-price will be replaced by quantity in sales/usage.
Finally, we've always believed in investing in what we know, and what we use. As early boomers and even generally healthy at this time, our use of meds has increased over the years. I would suspect that use will increase radically for our remaining years, along with our boomer cohorts.
Our opinion, since you asked...