Merck Overstated Mumps Vaccine Effectiveness?

Two former Merck virologists are charging in a whistleblower lawsuit that the drugmaker used improper testing techniques and falsified test data, among other things, to fraudulently overstate the effectiveness of its mumps vaccines for which the federal government has paid hundreds of millions of dollars. As a result, the former Merck employees also maintain that mumps outbreaks continue to occur.

Merck obtained its original, exclusive license for a mumps vaccine in 1967 and, at the time, stated that effectiveness was 95 percent, which meant that at least 95 percent of those inoculated were considered immunized from the disease, according to the lawsuit. However, new efficacy testing began in the late 1990s as part of an effort to win licensing for a second-generation measles, mumps and rubella vaccine, or MMR-II.

To maintain and win government contracts, Merck needed to achieve at least 95 percent efficacy, and childhood vaccines are a big business for Merck. The drugmaker does not separately list sales for the MMR-II vaccine, but this product and two other childhood vaccines generated $1.2 billion last year, a 12 percent drop that reflects manufacturing issues that caused shortages of ProQuad, a valeant vaccine that combats MMR and chickenpox (see page 3 here and here).

The lawsuit, however, states Merck struggled to achieve efficacy levels for MMR-II and so did not test its vaccine for an ability to protect against a wild-type mumps virus, which is a strain of the virus that exists in nature and would confront a person in the real world. Instcad, the lawsuit charges, Merck tested children's blood for its capacity to neutralize an attenuated virus that was the same mumps strain with which children were already vaccinated.

"The use of the attenuated strain, as opposed to a virulent wild-type strain, subverted the fundamental purpose of the test which was to measure the vaccine's ability to provide protection against a disease-causing mumps virus that a child would actually face in real life," the lawsuit charges. "The end result of this deviation from the accepted gold standard test was that Merck's test overstated the vaccine's effectiveness" (here is the lawsuit).

And so, Merck managers allegedly devised a new methodology for performing mumps efficacy testing under what was called Protocol 007 and that was designed to attain a 95 percent rate, according to the lawsuit filed by Stephen Krahling and Joan Wlochowski. They worked for the drugmaker at its West Point, Pennsylvania, facility at the time this effort began in 2000 and also claim they were pressured to participate in falsifying data.

What exactly was done? Merck added animal antibodies to both the pre- and post-vaccination blood samples. The lawsuit acknowledges this is "not uncommon" and helps to identify and count human antibodies that otherwise might not be identifiable on their own. In this way, animal antibodies make it easier to see the animal antibodies and do not alter what is being measured. "However, Merck added animal antibodies for the singular purpose of altering the outcome of the test by boosting the amount of virus neutralization counted in the lab," the lawsuit charges.

How so? Merck allegedly included in "its seroconversion measure all virus neutralizations, regardless of whether they resulted from human antibodies or by their combination with the animal antibodies. This enhanced methodology allowed Merck to increase dramatically the recordable instances of mumps virus neutralization and to count those neutralizations toward seroconverslon and its measure of the vaccine's success," according to the lawsuit.

Along the way, the former Merck virologists claim their boss destroyed "garbage bags" full of evidence and cancelled a contract with a lab in Ohio because test results could not be replicated. And Krahling, in particular, charges that he was threatened with jail time by a human resources representative if he contacted the FDA, which the virologist had threatened to do after meetings with Merck vaccine managers did not assuage his concerns.

Nonetheless, he called the FDA, which visited the drugmaker and conducted an interview that resulted in a one-page deficiency report. Separately, Merck conducted an audit, which one Merck vaccine manager had promised Krahling would take place, but this was not done independently, according to the lawsuit. Meanwhile, both virologists were barred from the lab where they had been working and took other positions, although both left Merck by 2002.

The lawsuit, by the way, was originally filed in 2010, but was recently unsealed after the US Department of Justice declined to intervene, or join, the litigation. A Merck spokesman tells us this: "We think this lawsuit is completely without merit. Merck presented to the Justice Department to show these allegations these are factually false and the Department of Justice did its own two-year investigation and did not choose to join the lawsuit.

"FDA examined the issues raised in this lawsuit and were satisfied with results of their own investigation. We intend to vigorously defend against the allegations raised by the plaintiffs in this lawsuit," he adds. "And none of the allegations related to the safety of MMR-II, and we're confident it helps to protect against measles, mumps and rubella, as described in the labeling."

vaccine pic thx to lulu on flickr