Shortly after the FDA granted approval for Shingrix in 2017, the Centers for Disease Control recommended it over the older shingles vaccine, Zostavax. Reports of serious side effects from Zostavax have also resulted in a growing demand for Shingrix – and now, patients looking to receive a shingles vaccine are finding it difficult to get.
Zostavax was first approved in 2006 and is basically a larger-than-normal dosage of regular chickenpox vaccines such as Varivax or Varilrix. It is what is known as an “attenuated vaccine,” meaning that it is essentially the live virus itself, altered in such a way as to make it less virulent. Ideally, such a vaccine contains the virus strong enough to activate the immune system and “train” it to recognize it, but weak enough that it can be overcome easily by bodily defenses.
Shingrix, on the other hand, is a “recombinant vaccine.” Such vaccines are produced by joining DNA molecules from different species. Shingrix contains a genetically-altered form of the varicella virus glycoprotein (the substance that allows them to bind to other molecules) but does not contain the live virus. Unlike Zostavax, which is administered in a single injection, Shingrix vaccination requires two dosages, spaced 2 to 6 months apart.
It also has fewer, less frequent side effects and greater efficacy (98 percent versus 51 percent for Zostavax). Now, a little over 2 years after its approval, pharmacies are experiencing shortages as demand for Shingrix grows. The reason is that the manufacturer, GlaxoSmithKline (GSK), has put limits on the amount that health care agencies are permitted to order.
Is something nefarious going on? Is this an attempt by GSK to create an artificial shortage and milk its new product for maximum profits? Given the history and behavior of Big Pharma, such suspicions are understandable and well-founded – but this is not necessarily the case for GSK and Shingrix.
The fact appears to be simply that the company was unprepared for such immediate demand, and currently lacks the resources and facilities to fulfill that demand. This problem was noted in July of 2018, when a company spokesperson told Reuters, “The arrival of Shingrix has been met with an unprecedented level of demand…healthcare professionals are vaccinating with Shingrix at a rate many times that of prior years, so ordering limits and intermittent shipping delays should be expected.”
A drug store owner in North Carolina said, “[GSK] spent money to advertise a product, and then they could not meet the demand with everyone needing to get the injection.” He added, “Zostavax is no longer recommended or even used. I haven’t seen a prescription for it in a long time.”
Currently, the waiting period for Shingrix is between six and nine months. As the general population gets older (zoster vaccine is recommended for all persons age 50 and over), the situation is expected to get worse.
According to GSK, shortages of Shingrix will continue for at least four more years. By then, the company plans to have a new bioreactor facility online for meeting the growing demand.