The Needle vs. The Nose

Of vaccine delivery methods, the needle is the one that brings the most apprehension to adults and children alike. Few alternate methods are currently available and include oral (e.g. oral polio vaccine) and, importantly for influenza, nasal mist. 

The nasal mist flu vaccine not only is easier to administer, not only does it mimic the means in which influenza sets up infection, it is a live but weakened--not killed--version of the flu. Data show that this version of the vaccine is preferred for children as it provides the more robust immunity than the ordinary vaccine. 

It was recently reported that the pioneering innovator who developed this vaccine, Hunein Maasab, died.

Commenting on his breakthrough vaccine, Dr. Maasab said: "I feel in a sense that I have accomplished my life’s dream." The secondary consequence of pursuing his life's dream--as it is for all innovators--was the bequest of a life-enhancing augmentation of man's armamenetarium against infectious disease. Thank you, Dr. Maasab.

Syphilis: Got an App for that?

It's often said--not without reason--that technology is the solution to infectious disease.

However, microbes can exploit that very technology to find routes into the body. Witness prosthetic joint infections, for example. 

The fact is that just as we use technology to enhance our lives, so do microbes. 

Case in point: the exploitation of hook-up apps by syphilis. By facilitating sexual encounters such apps also facilitate syphilis transmission. 

Talk about a 21st century problem.

Herpes: Creeping into Everything

A fascinating look at how infectious disease can adversely impact cognitive development was recently published in the Journal of Infectious Diseases. In this study, cognitive function was studied in three age groups: children, adults aged 20-59, and older adults. The study assessed the effect that two herpes viruses (HSV-1 and CMV) had on performance. 

The study found in children that seropositivity for HSV-1 was correlated to lower reading and spatial reasoning schools. In adults aged 20-59, seropositivity to HSV-1 and CMV was correlated to impaired coding speed and seropositivity to CMV was correlated to impaired learning and recall. In older adults, seropositivity to HSV-1 was linked to impaired immediate memory.

The implications of this study are that infection with these pathogens have wide-ranging effects that can substantially alter one's functional capacity. Indeed, both of these pathogens may have roles in Alzheimer's Disease as well. Preventing infection with these ubiquitous pathogens may prove difficult in the absence of a vaccine, however.

Mumps: Don't Call it a Comeback

In the midst of news regarding measles and pertussis, two diseases enjoying resurgences due to lack of immunity from lax vaccination attitudes (see this Pittsburgh Tribune Review article), mumps also appears to be making a comeback. In fact, however, the 2014 outbreaks at Fordham and Ohio universities are part of a trend that began in the US around 2006.

In contrast to the other vaccine preventable diseases, mumps appears to be somewhat mysterious in that it occurs in highly vaccinated populations and not in those lacking immunity. Such outbreaks didn't occur pre-2006 which leads to several questions: 

1. Has the mumps virus strain changed to a point where it is somewhat less likely to be stopped by the current vaccine's induced antibodies?
2. Do crowded conditions at college campuses somehow overwhelm immunity?
3. Are there super spreaders who shed high amounts of virus? 

Overall, though mumps is a much less virulent disease than measles and has less individual--and public health--import. 

Should Pneumococcal Meningitis Prompt a Public Health Response?

Here in Pittsburgh a 6 year old boy died from bacterial meningitis this week. There was some interest from the media and the county health department held a press conference to announce some of the specifics of the case, including the important fact that the culprit organism was treptococcus pneumoniae (the pneumococcus). As such, no major public health intervention--such as antibiotic prophylaxis--was needed. 

However, children dying of invasive pneumococcal disease is not something that should be considered commonplace in light of the availability of pneumococcal vaccines. The really are two pneumococcal vaccines that are relevant: the traditional 23-valent pneumococcal polysaccharide vaccine targeted primarily at the elderly and 13-valent (formerly 7) pneumococcal conjugate vaccine targeted primarily at children. 

While an important question will be whether the child was vaccinated and if the specific pneumococcus isolated was a vaccine serotype, I wonder what the pneumococcal vaccine rate is in his neighborhood. 

I think about this because of an innovative approach employed in Philadelphia for a similar problem that I once heard about in a lecture. In Philadelphia, rates of invasive pneumococcal disease are mapped with vaccination rates. Such an approach uncovers areas in which vaccine--which reduces carriage rate as well as infections--should be prioritized. The approach is reminiscent of the surveillance and containment approach used to eradicate smallpox.