Why does drug resistance readily evolve but vaccine resistance does not? | The Royal Society

Source: Why does drug resistance readily evolve but vaccine resistance does not? | Proceedings of the Royal Society of London B: Biological Sciences, by David A. Kennedy, Andrew F. Read

Time to first detection of human pathogens resistant to vaccines and antimicrobial drugs. Viral vaccines are labelled in purple, bacterial vaccines are labelled in green. Blue ‘x’s denote the first observations of resistance, with lines starting at product introduction (except for smallpox vaccination which began much earlier). Note that in all cases, substantial public health gains continued to accrue beyond the initial appearance of resistance.

Why is drug resistance common and vaccine resistance rare? Drugs and vaccines both impose substantial pressure on pathogen populations to evolve resistance and indeed, drug resistance typically emerges soon after the introduction of a drug. But vaccine resistance has only rarely emerged. Using well-established principles of population genetics and evolutionary ecology, we argue that two key differences between vaccines and drugs explain why vaccines have so far proved more robust against evolution than drugs. First, vaccines tend to work prophylactically while drugs tend to work therapeutically. Second, vaccines tend to induce immune responses against multiple targets on a pathogen while drugs tend to target very few. Consequently, pathogen populations generate less variation for vaccine resistance than they do for drug resistance, and selection has fewer opportunities to act on that variation. When vaccine resistance has evolved, these generalities have been violated. With careful forethought, it may be possible to identify vaccines at risk of failure even before they are introduced.

Post-apocalyptic life in American health care

Source: Post-apocalyptic life in American health care, by David Chapman

There is, in fact, no system. There are systems, but mostly they don’t talk to each other. I have to do that.

The hospital doctor on rounds said “Well, this is typical, especially with Anthem. It’s costing them several thousand dollars a day to keep her here, versus a few hundred dollars a day in a SNF, but it might take a week for them to figure out which local SNF they cover. Don’t worry, they’ll sort it out eventually.”

Hospitals can still operate modern material technologies (like an MRI) just fine. It’s social technologies that have broken down and reverted to a medieval level.

Systematic social relationships involve formally-defined roles and responsibilities. That is, “professionalism.” But across medical organizations, there are none. Who do you call at Anthem to find out if they’ll cover an out-of-state SNF stay? No one knows.

A central research topic in ethnomethodology is the relationship between formal rationality (such as an insurance company’s 1600 pages of unworkable rules) and “mere reasonableness,” which is what people mostly use to get a job done. The disjunction between electronic patient records and calling around town to try to find out who wrote a biopsy report that arrived by fax seems sufficiently extreme that it may produce a qualitatively new way of being.

In 2018 you don’t need to exercise more—you need to move more

Source: In 2018 you don’t need to exercise more—you need to move more

In our fervor for high intensity exercise, we seem to forget about exercise’s older, more elemental sibling: movement.

“We can grasp sedentary behavior as it relates to exercise because it’s easy to see the difference between exercising one hour a day and not exercising one hour a day,” Bowman writes. But few of us contemplate the “difference between exercising one hour a day and not exercising the other twenty-three.”

The Big Vitamin D Mistake

Source: The Big Vitamin D Mistake, Papadimitriou DT. J Prev Med Public Health. 2017.

J Prev Med Public Health. 2017 Jul;50(4):278-281. doi: 10.3961/jpmph.16.111. Epub 2017 May 10.

A statistical error in the estimation of the recommended dietary allowance (RDA) for vitamin D was recently discovered … The largest meta-analysis ever conducted of studies published between 1966 and 2013 showed that 25-hydroxyvitamin D levels <75 nmol/L may be too low for safety and associated with higher all-cause mortality, demolishing the previously presumed U-shape curve of mortality associated with vitamin D levels. Since all-disease mortality is reduced to 1.0 with serum vitamin D levels ≥100 nmol/L, we call public health authorities to consider designating as the RDA at least three-fourths of the levels proposed by the Endocrine Society Expert Committee as safe upper tolerable daily intake doses.