With the president’s declaration at last night’s presser that closing the border with Mexico would be useless because the H1N1 virus is already here, and the adamant rejection of border closing by Joe Biden this morning and Secretary Napolitano’s refusal to even seriously entertain the possibility that such a closure should happen before a Senate committee yesterday, the Obama Adminstration is committed to allowing free entry of any mutation of the H1N1 that occurs in Mexico into the U.S.
“We need to be prepared to close the border with Mexico if the swine flu outbreak escalates further,” Senator John McCain told Secretary Napolitano. “I hope you’ll continue to revisit this issue of whether we need to close the border or not.”
McCain is clearly right. A CDC history of the Spanish flu –the influenza epidemic of 1918-1919– details that three “waves” of the disease rolled across the world, and mutations seemed to have occurred along the way. Refusing to undertake stricter border controls simply denies the reality that new and deadlier strains could emerge from the original epicenter of the outbreak which is Mexico. To borrow and correct the president’s analogy: Some horses have escaped the barn, but there may be many, many more horses still inside. Doesn’t it make sense to shut the door on them, or to at least close those doors enough so that only a few escape every now and then? From the CDC’s study:
In the 1918-1919 pandemic, a first or spring wave began in March 1918 and spread unevenly through the United States, Europe, and possibly Asia over the next 6 months (Figure 1). Illness rates were high, but death rates in most locales were not appreciably above normal. A second or fall wave spread globally from September to November 1918 and was highly fatal. In many nations, a third wave occurred in early 1919 (21). Clinical similarities led contemporary observers to conclude initially that they were observing the same disease in the successive waves. The milder forms of illness in all 3 waves were identical and typical of influenza seen in the 1889 pandemic and in prior interpandemic years. In retrospect, even the rapid progressions from uncomplicated influenza infections to fatal pneumonia, a hallmark of the 1918-1919 fall and winter waves, had been noted in the relatively few severe spring wave cases. The differences between the waves thus seemed to be primarily in the much higher frequency of complicated, severe, and fatal cases in the last 2 waves.
But 3 extensive pandemic waves of influenza within 1 year, occurring in rapid succession, with only the briefest of quiescent intervals between them, was unprecedented. The occurrence, and to some extent the severity, of recurrent annual outbreaks, are driven by viral antigenic drift, with an antigenic variant virus emerging to become dominant approximately every 2 to 3 years. Without such drift, circulating human influenza viruses would presumably disappear once herd immunity had reached a critical threshold at which further virus spread was sufficiently limited. The timing and spacing of influenza epidemics in interpandemic years have been subjects of speculation for decades. Factors believed to be responsible include partial herd immunity limiting virus spread in all but the most favorable circumstances, which include lower environmental temperatures and human nasal temperatures (beneficial to thermolabile viruses such as influenza), optimal humidity, increased crowding indoors, and imperfect ventilation due to closed windows and suboptimal airflow.
However, such factors cannot explain the 3 pandemic waves of 1918-1919, which occurred in the spring-summer, summer-fall, and winter (of the Northern Hemisphere), respectively. The first 2 waves occurred at a time of year normally unfavorable to influenza virus spread. The second wave caused simultaneous outbreaks in the Northern and Southern Hemispheres from September to November. Furthermore, the interwave periods were so brief as to be almost undetectable in some locales. Reconciling epidemiologically the steep drop in cases in the first and second waves with the sharp rises in cases of the second and third waves is difficult. Assuming even transient postinfection immunity, how could susceptible persons be too few to sustain transmission at 1 point and yet enough to start a new explosive pandemic wave a few weeks later? Could the virus have mutated profoundly and almost simultaneously around the world, in the short periods between the successive waves? Acquiring viral drift sufficient to produce new influenza strains capable of escaping population immunity is believed to take years of global circulation, not weeks of local circulation. And having occurred, such mutated viruses normally take months to spread around the world.
If the president wants to explain that the costs of shutting down the border are too high, that would be different. But it is simply not true that the United States would be just as exposed to the pandemic with an open versus a closed or partially closed border. Evey day that he does not act is another day of open invitation to the original virus or any of its mutations to make the trip north. France understands this, and is pressing the EU to suspend flight rom Mexico even though the flu is already on the European continent. Argentina and Cuba have already suspended flights from Mexico.
Has the president considered that not closing down the borders increases the risk that these and other countries will soon be restricting flights from America into their country. If we continue to define ourselves as “just like Mexico” vis-a-vis the H1N1, then the rest of the world can be expected to treat us accordingly.