Flu Vaccine Mismatch: Maybe Use Match.com or eHarmony Next Time?

Yesterday the CDC released an alert that described an unfortunate phenomenon that has occurred with this year's flu season: a vaccine mismatch. This is not a surprising development as mismatches are known to happen as predicting flu strains can be very difficult given flu's ability to shift and drift.  But when such mismatches occur they can be expected to diminish the 60% effectiveness of the vaccine.

What happened this year was that the H3N2 strain included in the vaccine does not match over half of the H3N2 strains isolated thus far. If H3N2 strains were only predicted to be a minor part of this year's flu season this fact might not much a difference, but it looks like we might be in for an H3N2 dominant season so this could become very significant. In general, H3N2 seasons tend to be more severe than those dominated by other strains so we may be in for a rough winter.

The mismatched strain, which first appeared in March 2014, has already been slated for inclusion in the upcoming vaccine for the Southern Hemisphere, whose flu season is the mirror image of the Northern Hemisphere's season. But, given the lead time needed to make flu vaccines, it's not something that could have been incorporated into this season's Northern Hemisphere vaccine.  

It's important to remember that, despite the mismatch, the flu vaccine is something that everyone should still received as this mismatch is only for 1 of 4 strains and the other strains will certainly cause disease this season. 

The only way to eliminate the chances of future mismatches is the development of a universal flu vaccine that targets a part of the virus that does not change. That would be a true game changer. 

Hockey Players with Swollen Faces: Puck, Fist, or Mumps?

Professional sports teams, because of the close contact amongst players, are always ripe for outbreaks of contagious diseases. In the recent past MRSA has been one organism associated with sports-related outbreaks (see the St. Louis Rams).  Today, the NHL is now facing an outbreak of mumps that has plagued several teams. 

Mumps is a viral disease and is generally preventable through vaccination. It is one of the "M's" in the MMR vaccination. This vaccine, like many others, is due to the genius of Maurice Hilleman--one of the true heroes of infectious disease. It is known for causing characteristic swelling of the salivary glands but can also meningitis or orchitis (inflammation of the testicles).

However, over the past several years we've seen large outbreaks of mumps occur in certain population that are somewhat dense such as amongst college students. Interestingly, these outbreaks are occurring in relatively highly vaccinated groups of individuals (vs. measles, for example). 

So why are these outbreaks occurring? When a vaccine fails I think of one of two causes: the pathogen has mutated or the immunity induced by the vaccine has fallen below a protective threshold. While the strains causing these outbreaks (G) is different than the vaccine strain (A), G strain outbreaks are halted by the A strain vaccine. So strain disparity doesn't seem to be the explanation. There has been some suggestion that a third booster dose of the vaccine can bring outbreaks to a halt supporting the waning immunity theory.

Another factor is something called "exposure pressure." Since these outbreaks are occurring in specific "closed" populations could it be that the amount of exposure an adequately vaccinated individual has to the virus in these outbreak settings overwhelms the immune system?

My hypothesis is that it is probably waning immunity coupled to exposure pressure that explains these outbreaks. Outside of outbreak settings mumps has become much less common and any natural boosting of vaccine immunity from exposure to natural cases is no longer present, allowing antibody levels to fall. Those with waning immunity are simply unable to resist the virus when faced with the exposure pressure in a closed population in which mumps is being harbored.

There are reports that some teams are moving forward with booster doses, which should stem the outbreak. But, it remains important to understand more fully why these outbreaks continue to occur and whether universal 3rd boosters should be considered for certain populations.

A Biosecurity Lesson Courtesy of Castle

The plot of the latest episode of Castle was ripped right from a bioterrorism scenario and was well worth watching. The episode weaved together various elements that are all very real concerns including:

• The theft of a deadly pathogen from a laboratory
• The deliberate infection of someone via a novel device
• The anticipation of that person spreading the pathogen
• Stockpiling of vaccines

To fill in the blanks, a vial of H5N1 avian influenza goes missing, a man is infected via his asthma inhaler, individuals on the subway with this man are exposed, and stockpiled vaccine is administered to contacts.

I was pleasantly surprised that most of the science was right and there was an acknowledgment of the realm of biosecurity on such a popular television show, illustrating that the general public has not only understanding of these issues but also an appreciation. 

A Hepatitis C Lesson Inspired by Ice Cube

I have a serious obsession with infectious diseases and constantly search for references everywhere. My latest find: the movie Ride Along. This comedy is about a police officer (played by Ice Cube, who I once saw in concert) and an aspiring police officer (played by Kevin Hart). The infectious disease reference occurs in a scene in which the police officer questions the neophyte's resolve asking him how he would react if he were stuck with a hepatitis C needle. 

Hepatitis C is and injection drug use are indelibly linked: 90% of new infections are due to this risk factor. Needle exchange programs are the cornerstone of hepatitis C prevention and it is unfortunate, that despite the unequivocal evidence that supports them, political opposition exists. In Pittsburgh, we are luck to have an organization called Prevention Point Pittsburgh, whose board I serve on, that provides needle exchange and disposal services. Pennsylvania also allows needles to be sold without a prescription, another key component to hepatitis C prevention. 

Clean needles lead to a lowering of hepatitis C incidence and prevalence. This translates into a lower chance that a discarded needle will be contaminated with hepatitis C. 

Until a vaccine is developed for hepatitis C clean materials with which to inject drugs, coupled with extensive testing, are the primary means of prevention. 

Ebola in Semen: A Worry for Nymphomaniacs, Not A Basis for Detention

Countries all around the globe are now conducting some sort of entry screening of travelers from Ebola-afflicted nations. These processes will involve temperature checks and a survey of symptoms coupled to a risk-assessment based on the person's activities. It is non-invasive and if suspicion is aroused, more testing is performed. Individuals who are flagged may be escorted to a room that has the requisite medical equipment present. 

Right now, I am trying to imagine the case of the man in India who was taken to a room that, perhaps, was strewn not with thermometers, but with Playboy magazines as part of an "enhanced" screening program that must be in place there.

The man in question had survived Ebola in Liberia but is now under detention. He is not under this order because of the presence of any lingering symptoms of Ebola, however. He clearly passed exit screening when he embarked on his trip and had not developed any new symptoms upon arrival. 

He is being detained because his semen tested positive for Ebola -- something that we know can occur for up to 3 months after infection. Such a condition is remedied by safe sex counseling and is not a basis for isolation or detention.

I can't imagine the protocol details that are in place that are used to elicit the requisite body fluid or what the rationale for detention may be (unless it is only used for nymphomaniacs).

Hopefully, he gets to keep his "reading" material for it may be months before his semen tests negative. 

Such actions divert important resources and feed the irrational panic surrounding this virus.