Past generations of professional hockey players were never at risk of mumps outbreaks. Today's players are, and tomorrow's will be, along with adults generally. These outbreaks -- which the media portray as coming out of the blue -- don't surprise anyone in medical circles who has been paying attention. Mumps outbreaks among aduIts have long been predicted by public health experts. Ironically, the mumps vaccine itself makes these outbreaks inevitable.
A century ago, before sanitation and public health improvements, mumps was a risky disease. By the 1950s, it had become largely benign, a childhood disease that especially hit five- to nine-year-olds, and almost everyone by their late teens. Once infected, children obtained lifetime immunity, making mumps rare in adulthood.
Because mumps was dangerous in adults -- complications can include sterility in males and, in pregnant women, the loss of the child -- public health authorities in the 1950s and 1960s predicted that the mumps vaccine then being proposed would backfire.
Mumps and other once-perilous childhood diseases "have been brought under control and there is cause to rejoice in the fact ... that epidemics are becoming scarce," Dr. E. H. Lossing, the chief of epidemiology at the federal government's Department of Health and Welfare, wrote in 1955.
Mumps no longer remained "of sufficient gravity in terms of morbidity, mortality or disability to justify universal and probably repeated vaccination. Unless lifelong immunity is conferred by the primary vaccination, which seems unlikely, should the attack merely be postponed to older ages when economic loss and risk of complications are greater?"
Dr. Lossing was prescient on all counts. The mumps vaccine does not confer children with lifelong immunity, repeated vaccinations have become the rule, and mumps has become an adult disease that threatens to be costlier in terms of both time off work and health. But mumps vaccination has turned out to be even iffier than Dr. Lossing might have imagined, because the mumps vaccine is a staggering underperformer.
For one thing, the vaccine is a dud with many, accomplishing no good at all. "Right off the bat, when you give it to 100 people, 15 won't respond," states Dr. Gregory Poland, head of the Mayo Clinic's Vaccine Research Group, one of the world's largest and most authoritative. Even when the vaccine does take, its full benefit often doesn't last long -- just one or two years before the level of antibodies drops below the level required to protect against mumps, according to a study in the Journal of Infectious Diseases. By the eighth year, the antibody levels have plummeted to just one third the level required for protection.
Our individual genetic makeup is a factor, possibly explaining why even fully vaccinated super-fit athletes like Sidney Crosby can become infected. "There are some people who carry specific forms of immune function genes so that they don't respond or they respond poorly to a vaccine," Dr. Poland explained. Crosby appears to have overcome his bout with mumps, as most do, but genetic predispositions can sometimes lead to tragedy. To date, the U.S. government's Vaccine Injury Compensation Program has received 962 claims for serious injuries involving mumps vaccines, 58 of them causing deaths, and granted compensation in 371 claims.
Sometimes the problem isn't with the person but with the vaccine. According to a 2012 study by the Office of Inspector General of the U.S. Department of Health and Human Services, children's vaccines managed by 76 per cent of vaccine providers "were exposed to inappropriate temperatures for at least five cumulative hours [which] can reduce vaccine potency and efficacy." Vaccines "are only as good as their storage and administration," Dr. Poland said.
The mumps vaccine may suffer from another problem, too -- scientific misconduct. In September, a U.S. District Court found plausible claims that pharmaceutical giant Merck falsified data and otherwise engaged in fraudulent activities in order to win U.S. Food and Drug Act approval -- and a monopoly in the U.S. market -- for its mumps vaccine. Merck will as a result be appearing in at least two federal court cases to defend itself: United States v. Merck & Co and Chatom Primary Care v Merck & Co, a class action suit by doctors and medical practices who claim they were sold an overpriced and defective product.
Both court cases stem from two former Merck scientists-turned-whistleblowers who participated in the falsifications first hand and, according to court documents, were ordered by Merck to keep silent about the test results, which showed the vaccine to be less effective than needed to be licensed. The falsified, fraudulently robust results discouraged competing manufacturers from entering the mumps market, preventing a truly efficacious vaccine from being developed and making Merck a monopoly provider. The court documents also state that Merck expected increased outbreaks of mumps over time because its vaccine would fail.
As it turned out, outbreaks among the vaccinated came: 2006 saw more than 6,500 cases in the U.S. Midwest -- the largest in 20 years -- with 84 per cent of the young adults afflicted having had two doses of the mumps vaccine. In 2009, 5,000 cases occurred, again among those with a high vaccination rate.
Mumps outbreaks, in fact, occur continually, most of them small and unreported. In the first 11 months of 2014, the outbreaks in the U.S. added up to 1,078 cases of mumps. They are attracting attention today only because NHL players are involved. And they will attract attention in future because mumps will more and more become an adult worry.
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