So-called pub­lic emer­gen­cies al­ways seem to hap­pen in T&T on Fri­day af­ter­noon. Last Fri­day was a par­tic­u­lar­ly in­aus­pi­cious one, last day of the month, pay­day, heavy rain, pro­lon­ga­tion of the SoE, the de­par­ture of the lat­est Amer­i­can war­ship 24 hours be­fore, the ar­rival of the newest Amer­i­can fes­ti­val, news from the Mi­a­mi Her­ald that the US was about to strike Venezuela, the no­tice that the T&T De­fence Force had been put on a State One Alert Lev­el and the po­lice be­ing ef­fec­tive­ly con­fined to bar­racks.

On Sat­ur­day, the T&T Guardian re­port­ed that Deputy Com­mis­sion­er of Po­lice Ju­nior Ben­jamin said “based on all that was shared on so­cial and tra­di­tion­al me­dia, the ex­ec­u­tive de­cid­ed to stop the leave of all of­fi­cers.”

This sug­gests that the po­lice de­cid­ed to stop the leave of all of­fi­cers based on some­thing pub­lished on so­cial and tra­di­tion­al me­dia.

I hope that in­ter­pre­ta­tion is wrong. I would hate to think that our se­cu­ri­ty forces make such se­ri­ous de­ci­sions, caus­ing pan­ic in the pop­u­la­tion, based on what they see in the me­dia.

Herd im­mu­ni­ty against pan­ic is ten­u­ous in T&T.

Re­lat­ed to herd im­mu­ni­ty, in­fec­tious dis­eases con­tin­ue to wreak hav­oc on chil­dren. Diph­the­ria, whoop­ing cough, tetanus, po­lio and measles are killing chil­dren right, left and cen­tre.

All are among the dis­eases that were relics of pre-vac­cine days but have resurged in re­cent years, with mass dis­place­ment dri­ven by cli­mate change and war. Dis­rup­tions in rou­tine im­mu­ni­sa­tion be­cause of COVID, its stress on glob­al health sys­tems and the ac­com­pa­ny­ing rise in vac­cine hes­i­tan­cy, have fu­elled their spread.

One that is not usu­al­ly dis­cussed is diph­the­ria. There are large diph­the­ria out­breaks in So­ma­lia, Su­dan, Yemen and Chad, and there have been near­ly 30,000 re­port­ed cas­es in Nige­ria in the last two years. We are talk­ing fig­ures in the thou­sands.

Diph­the­ria is caused by bac­te­ria that pro­duce a tox­in that kills cells in the throat and ton­sils, cre­at­ing a thick mem­brane of dead tis­sue that can grow large enough to block the air­way and cause suf­fo­ca­tion. It is par­tic­u­lar­ly dan­ger­ous in young chil­dren with small air­ways.

In the era be­fore a vac­cine to pre­vent or an­tibi­otics to treat diph­the­ria were avail­able, pae­di­a­tri­cians would let the nail on one of their lit­tle fin­gers grow long. This was used to cut an air­way through the diph­ther­ic mem­brane in an emer­gency.

So­ma­lia’s cur­rent diph­the­ria out­break has grown steadi­ly since it be­gan in 2023, with more than 2,000 cas­es re­port­ed. At the main hos­pi­tal in the cap­i­tal, Mo­gadishu, near­ly 1,000 pa­tients have been ad­mit­ted to the diph­the­ria ward this year, com­pared with 49 in 2024. Eighty per cent of them are chil­dren.

Near­er home, be­tween Ju­ly 2016 and 2019, Venezuela ex­pe­ri­enced a diph­the­ria out­break with over 1,700 cas­es and 160 deaths.

Diph­the­ria is not the on­ly in­fec­tious prob­lem in Venezuela. Be­tween Oc­to­ber and De­cem­ber, 2021, an out­break of yel­low fever, in­volv­ing 18 hu­man cas­es, was re­port­ed in Mon­a­gas, right across the Gulf of Paria from us.

We are at risk from con­ta­gious dis­eases and con­ta­gious pan­ic.

The prob­lem with both is the de­crease in herd im­mu­ni­ty, which is the per­cent­age of the pop­u­la­tion that needs to be vac­ci­nat­ed to pre­vent the ap­pear­ance of a dis­ease or so­cial pan­ic. This is called the herd im­mu­ni­ty thresh­old.

Herd im­mu­ni­ty against pan­ic is low here.

That per­cent­age of peo­ple who need to be im­mune in or­der to achieve herd im­mu­ni­ty varies with each dis­ease and pop­u­la­tion. In gen­er­al, med­i­cine tries for at least a 90 per cent herd im­mu­ni­ty lev­el but it varies from dis­ease to dis­ease. Be­cause measles is so con­ta­gious, herd im­mu­ni­ty against measles re­quires about 95per cent of a pop­u­la­tion to be vac­ci­nat­ed. The re­main­ing 5per cent will be pro­tect­ed by the fact that measles will not spread among those who are vac­ci­nat­ed.

How­ev­er, if a child with measles comes in­to a doc­tor’s of­fice and coughs once or twice, that’s that. The measles virus, un­like the COVID virus, can sur­vive up to two hours in an en­closed space and will in­fect any­one with­out im­mu­ni­ty, in­clud­ing that 5per cent.

Po­lio is an­oth­er that needs at least 95per cent of the pop­u­la­tion to be im­mu­nised to pre­vent an­oth­er po­lio out­break. Whoop­ing cough and yel­low fever are at 90per cent, and the oth­ers, diph­the­ria, mumps, Ger­man measles and chick­en­pox, are all be­tween 80 and 85per cent.

Tetanus is sin­gu­lar, in that herd pro­tec­tion does not func­tion here. Tetanus is not a trans­mis­si­ble, per­son-to-per­son dis­ease. You get tetanus from con­t­a­m­i­nat­ed sub­stances, a rusty nail etc., not a con­t­a­m­i­nat­ed per­son.

It’s not a nice thing to say but it must be said. Par­ents who choose not to im­mu­nise their child are de­pen­dent on oth­er par­ents im­mu­nis­ing their own chil­dren to achieve herd pro­tec­tion, so as to pro­tect their unim­mu­nised child.

How to pro­tect against pan­ic is some­thing else.