KEVON FELMINE
kevon.felmine@guardian.co.tt
While sci­en­tists project 12-18 months be­fore they can de­liv­er a COVID-19 vac­cine to the world, there re­mains un­cer­tain­ty over its ef­fec­tive­ness and when it will reach T&T.
At yes­ter­day's Min­istry of Health COVID-19 up­date, Dr Chris­tine Car­ring­ton, Pro­fes­sor of Mol­e­c­u­lar Ge­net­ics and Vi­rol­o­gy at the Uni­ver­si­ty of the West In­dies, said the avail­abil­i­ty of a vac­cine in T&T would de­pend on the pro­duc­tion rates and quan­ti­ties.

"An ef­fec­tive vac­cine against SARS-CoV-2 may like­ly be the on­ly long term so­lu­tion to con­trol­ling the COVID-19 pan­dem­ic. To date, there are over 125 vac­cines in de­vel­op­ment and the lev­el of these have reached the stage of clin­i­cal tri­als, mean­ing that they are be­ing test­ed in hu­mans," Car­ring­ton said.
"Vac­cine de­vel­op­ment is a long and com­plex process, in­volv­ing pre­clin­i­cal lab­o­ra­to­ry stud­ies, an­i­mal stud­ies, then sev­er­al lev­els of what we call phas­es of clin­i­cal tri­als, in­volv­ing vac­ci­na­tion and the sub­se­quent chal­lenge of peo­ple with the virus. If a vac­cine is proven to be safe and ef­fec­tive af­ter all of this, then there are dif­fi­cul­ties tran­si­tion­ing to man­u­fac­tur­ers. Man­u­fac­tur­ing has to be done on a large scale un­der the very strict con­di­tion and fi­nal­ly you move to dis­tri­b­u­tion."

Ac­cord­ing to Na­tion­al Ge­o­graph­ic, the mumps vac­cine is con­sid­ered the fastest ever ap­proved, tak­ing four years from col­lect­ing vi­ral sam­ples to li­cens­ing a drug in 1967.
Last month, African Union chair­man Cyril Ramaphosa called for any COVID-19 vac­cine that is de­vel­oped to be made patent-free, pro­duced at scale and made avail­able at no cost glob­al­ly.
At a World Health Or­gan­i­sa­tion's (WHO) World Health As­sem­bly held last month, a unan­i­mous res­o­lu­tion was passed by the 194 WHO mem­ber states, call­ing on the Di­rec­tor-Gen­er­al Tedros Ghe­breye­sus to rapid­ly iden­ti­fy and pro­vide op­tions for scal­ing up the de­vel­op­ment, man­u­fac­ture and dis­tri­b­u­tion ca­pac­i­ties need­ed for pro­vid­ing ac­cess to COVID-19 di­ag­nos­tics, ther­a­peu­tics, med­i­cines and vac­cines.
Car­ring­ton said vac­cine de­vel­op­ment av­er­ages about 10-15 years but for COVID-19 there are col­lab­o­ra­tions be­tween pri­vate and pub­lic en­ti­ties to speed up the out­come.
"Even at this ac­cel­er­at­ed rate, many ex­perts be­lieve that it will be about 18 months be­fore a vac­cine is ready for roll­out," she said.
Car­ring­ton said there was op­ti­mism that one of the vac­cines un­der clin­i­cal tri­als will be ready be­fore the year ends.

The Uni­verisi­ty of Ox­ford's AZD1222 SARS-CoV-2 vac­cine is tout­ed as the most ad­vanced, she said. For­mer­ly called ChA­dOx1, it is the weak­ened ver­sion of an ade­n­ovirus (com­mon cold). Car­ring­ton said this caus­es in­fec­tions in chim­panzees but was mod­i­fied so that it could not mul­ti­ply in hu­man cells.

"Ini­tial hu­man tri­als show that it is safe and well-tol­er­at­ed and trig­gers a strong im­mune re­sponse that is able to recog­nise SARS-CoV-2. An­i­mal stud­ies show that al­though vac­ci­nat­ed an­i­mals can still be in­fect­ed by SARS-CoV-2, the lev­el of virus is low­er than in un­vac­ci­nat­ed an­i­mals. The vac­ci­nat­ed an­i­mals did not de­vel­op pneu­mo­nia, so there is some lev­el of pro­tec­tion," Car­ring­ton ex­plained.
A phase three clin­i­cal tri­al in­volv­ing 10,000 UK vol­un­teers will now de­ter­mine whether peo­ple who re­ceived AZD1222 vac­cines are less like­ly to con­tract COVID-19 or de­vel­op symp­toms against those who were giv­en non-COVID-19 vac­cines, she said. The re­sults are ex­pect­ed in Au­gust.
How­ev­er, Car­ring­ton said with in­fec­tions slow­ing down in the UK, there is a con­cern about whether there are enough in­fect­ed peo­ple for re­searchers to de­ter­mine the dif­fer­ence be­tween the two groups. Even be­fore those re­sults re­turn, the Coali­tion for Epi­dem­ic Pre­pared­ness and In­no­va­tions and As­traZeneca are prepar­ing to pro­duce 2 bil­lion dos­es of the vac­cine. This in­cludes 400 mil­lion from the US and UK and 1 bil­lion dos­es for low and mid­dle-in­come coun­tries.
"If the vac­cine is proven to be safe and ef­fec­tive, the first dos­es are an­tic­i­pat­ed to be avail­able lat­er this year and the first 300 mil­lion ready by Ju­ly next year." 
Chi­na's CanSi­no Bi­o­log­ics and the US's Mod­er­na are al­so de­vel­op­ing sim­i­lar vac­cines that have been well tol­er­at­ed so far.
While a COVID-19 vac­cine will go a long way to help­ing coun­tries to re­turn to nor­mal­cy, Health Min­is­ter Ter­rence Deyals­ingh not­ed that an­ti-vaxxers ex­ist in T&T. Deyals­ingh said there were even an­ti-vaxxers in the Par­lia­ment.

In 2019, WHO list­ed vac­cine hes­i­tan­cy as one of 10 threats to glob­al health.

But Car­ring­ton said once there are enough peo­ple vac­ci­nat­ed in a pop­u­la­tion, the chance of an out­break is low as there would be "herd im­mu­ni­ty." 
How­ev­er, she ac­knowl­edged that for some vac­cines, those who are im­muno­com­pro­mised, very young or old, may not be able to be vac­ci­nat­ed. Some peo­ple al­so de­vel­op al­ler­gic re­ac­tions to vac­cines.

As for pre­pared­ness, Deyals­ingh said it was too ear­ly to de­ter­mine how the vac­ci­na­tion would roll out as the min­istry would have to know the var­i­ous pro­to­cols for stor­ing and dis­pens­ing. Once a vac­cine is de­vel­oped, he said the min­istry would work with the Pan Amer­i­can Health Or­gan­i­sa­tion to vac­ci­nate the pop­u­la­tions.