Saturday, June 17, 2017

Unexpected threat from low vaccination rates…no treatment available 

The return of a rare disease could be devastating. While a cure exists, it may not be not available.
Vaccines have been important elements of public health care, yet over the last decade we have witnessed vaccination rates decrease in various areas worldwide. In general, the reversing trend is in the industrialized world, leading to cases like the measles outbreaks in California in 2015 and Minnesota in 2017.
But there is an insidious downside hiding in lower vaccination rates — what if vaccination rates decrease and a pathogen, once thought eliminated, returns? In some cases the antitoxins used to combat the pathogen are no longer available, or if they exist, they are in restricted supply.
Basically, it is supply and demand. There’s no need for anti-sera production when disease incidence is repressed through routine immunization. Who creates an expensive solution to a non-problem? Simply put, no demand, no supply. Existing batches are produced in small labs in a few countries. Laws that have been instilled since diseases were well controlled, often prohibit the movement of blood-derived treatments across international lines. Sadly, sometimes a cure exists, but cannot be implemented.
This situation is highlighted in a case described in the January 13, 2017 issue of Science magazine. A three-year-old girl was admitted to a hospital in Antwerp, Belgium in March of 2016. She was diagnosed with having severe tonsillitis, but physicians noted an unusual thick layer of grey dead cells covering her throat. It was a hallmark symptom for diphtheria known as a “pseudomembrane”. Diphtheria is caused by the bacterium Corynebacterium diphtheriae. The initial symptoms present as a sore throat and fever, and can progress to blocking the lungs if left untreated. The exotoxin secreted by the bacteria can also cause damage to the heart and liver.
The disease is treated with antibiotics, and also an antitoxin produced in horses.
However there was no antitoxin available in Belgium to treat this patient. The European Centre for Disease Prevention and Control in Stockholm Sweden eventually was able to locate the treatment in The Netherlands. But it was too little too late, and the infected child died before the life-saving treatment could be administered.
There is a scattering of cases just like this each year. The antitoxin has a shelf life and is produced only in a few countries including Russia, Brazil, and India. A company called BulBio located in Bulgaria is the only producer within the European Union. Strict EU rules regarding importing blood-derived products means the whole EU has only one potential supplier.
In the USA all stores of the antitoxin expired in the 1990’s. When cases are reported, the antitoxin must be imported from Brazil.
To make matters worse, there is no incentive to make the antitoxin. It’s an expensive process to produce it from horses and doses are inconsistent from batch to batch, meaning a lot of pretesting and quality control are necessary before it may be distributed. To produce them in cell culture would require a new infrastructure and certifications, testing would have to be performed for safety, all which are extremely expensive which makes it a cost-prohibitive, bureaucratic nightmare for any company to undertake to develop a cure for a problem that happens a few times a year around the globe.
In the United States between 2004 and 2015, 2 cases of diphtheria were reported. But in places like Ukraine diphtheria vaccination rates hover below 50%. They are not alone. When a substantial outbreak occurs, where will the treatment come from? It is not a question of “if” — it is a question of “When?”
The diphtheria antitoxin issue raises an important and rarely discussed facet of the vaccination issue. When diseases have been strongly suppressed by routine vaccination, their remedies (all expensive to produce and with a shelf life) fall in short supply. The associated industries have been mothballed and new production techniques are not economically feasible.
The case of diphtheria underscores another reason why vaccination is important. When a defeated disease re-emerges, the cure you or your family critically needs may not be available.