JavaScript is disabled in your web browser or browser is too old to support JavaScript. Today almost all web pages contain JavaScript, a scripting programming language that runs on visitor's web browser. It makes web pages functional for specific purposes and if disabled for some reason, the content or the functionality of the web page can be limited or unavailable.

Wednesday, February 26, 2025

Is the Omicron subvariant BA.2 more transmissible?

by

1115 days ago
20220207
An illustration of two COVID viruses with legs and arms in a relay race. One is passing the baton to the other. [Muaz Kory/Al Jazeera]

An illustration of two COVID viruses with legs and arms in a relay race. One is passing the baton to the other. [Muaz Kory/Al Jazeera]

■ Could BA.2 pro­long the Omi­cron wave of the COVID pan­dem­ic? ■

 

DOC­TOR'S NOTE By Dr Amir Khan | Al Jazeera

 

(AL JAZEERA) — Since its emer­gence in late 2021, Omi­cron (or BA.1) has quick­ly be­come the dom­i­nant vari­ant of the COVID-19 virus. The mu­ta­tions it har­boured meant it was more trans­mis­si­ble than the Delta vari­ant, so was able to spread rapid­ly through pop­u­la­tions around the world. It has been found to con­fer a milder ill­ness than Delta – though milder should not be mis­tak­en for mild.

Sci­en­tists are now track­ing a sub­group of the Omi­cron vari­ant, known as BA.2, which was first iden­ti­fied in In­dia and South Africa in late De­cem­ber 2021. Since then, it has been found in the US and Eu­rope. The sub­vari­ant is thought to have 20 ad­di­tion­al mu­ta­tions on its spike pro­tein com­pared with BA.1, though sci­en­tists are not quite sure what this will mean for the course of the pan­dem­ic. So far, there is in­suf­fi­cient ev­i­dence to de­ter­mine whether BA.2 caus­es more se­vere ill­ness than BA.1.

The rea­son why some peo­ple re­fer to BA.2 as the “stealth” vari­ant is be­cause they claim it is not as easy to de­tect on PCR and lat­er­al flow tests. This is in fact not true; it can be de­tect­ed on both types of tests.

PCR tests look for three dif­fer­ent DNA se­quences when de­tect­ing the SARS-CoV-2 virus and will show a pos­i­tive re­sult if at least two se­quences are present. One of the se­quences the test looks for is the S-gene, which is found on the spike pro­tein. This is ab­sent in the BA.1 Omi­cron vari­ant and is known as the “S-gene dropout”; PCR tests will still re­turn a pos­i­tive re­sult as they will de­tect the oth­er two DNA se­quences they are de­signed to pick up. But the ab­sence of the S-gene means it was easy for sci­en­tists to dif­fer­en­ti­ate be­tween BA.1 Omi­cron and Delta, which had the S-gene present. Like Delta, the BA.2 Omi­cron vari­ant has the S-gene present, so it is hard­er for sci­en­tists to tell the dif­fer­ence be­tween BA.2 and Delta, hence the term “stealth” vari­ant. But in an­oth­er way, this might ac­tu­al­ly work in our favour: with Omi­cron now dom­i­nant and Delta quick­ly dis­ap­pear­ing, any PCR tests that de­tect the pres­ence of the S-gene go­ing for­ward are like­ly to be the BA.2 sub­vari­ant of Omi­cron.

This vari­ant has be­come dom­i­nant in Den­mark. The speed at which cas­es have risen there and in oth­er coun­tries like the UK sug­gests that BA.2 may be more trans­mis­si­ble and able to out­com­pete the BA.1 vari­ant. A re­cent study looked at the trans­mis­sion of Omi­cron sub­vari­ants in Dan­ish house­holds and found that the BA.2 sub­vari­ant is sub­stan­tial­ly more trans­mis­si­ble than the orig­i­nal vari­ant.

The study looked at house­holds in Den­mark who had one per­son test pos­i­tive for Omi­cron be­tween De­cem­ber 20, 2021 and Jan­u­ary 11, 2022. They had 2,122 peo­ple who were pos­i­tive with BA.2 and 6,419 peo­ple with BA.1. The re­searchers then fol­lowed these peo­ple to see if they passed on their sub­vari­ants of Omi­cron to oth­er mem­bers of their house­hold. They found that the BA.2 sub­vari­ant trans­mit­ted more in both un­vac­ci­nat­ed and vac­ci­nat­ed mem­bers of the house­hold when com­pared with the BA.1 sub­vari­ant. But they al­so found that peo­ple who were un­vac­ci­nat­ed were more like­ly to trans­mit BA.2 than those who were vac­ci­nat­ed.

Er­ic Topol, an Amer­i­can car­di­ol­o­gist and sci­en­tist, and founder of the Scripps Re­search Trans­la­tion­al In­sti­tute, said about the study that the BA.2 vari­ant find­ings sug­gest triple vac­ci­na­tion pro­tects well against symp­to­matic in­fec­tion, but he al­so warned that the in­creased trans­mis­si­bil­i­ty will like­ly pro­long the Omi­cron wave in some places.

The BA.2 lin­eage does not ap­pear to cause more se­vere dis­ease, so there is no rea­son to pan­ic. It is im­por­tant to note that it is not un­usu­al to have sub­groups of the same vari­ant – that is the na­ture of a virus that is able to mu­tate and which has as many hu­man hosts as Omi­cron does. Vac­cines still of­fer pro­tec­tion against se­ri­ous ill­ness and, ac­cord­ing to the study, al­so pro­tec­tion against trans­mis­sion, so it re­mains im­por­tant to take them up when of­fered.

An illustration of vaccine phials and a syringe, with the coronavirus seen in a magnifying glass.  [Jawahir Al-Naimi/Al Jazeera]

An illustration of vaccine phials and a syringe, with the coronavirus seen in a magnifying glass. [Jawahir Al-Naimi/Al Jazeera]

 

Per­son­al Sto­ry: The UK gov­ern­ment’s U-turn on NHS COVID vac­cine man­date

 

There has been much de­bate in re­cent weeks over the UK gov­ern­ment’s de­ci­sion to man­date COVID-19 vac­cines for all Na­tion­al Health Ser­vice (NHS) work­ers come April 1, 2022. Sajid Javid, the coun­try’s health sec­re­tary, stat­ed it was the “du­ty” of NHS staff to get vac­ci­nat­ed, ar­gu­ing it would keep them and their pa­tients safe.

But with an es­ti­mat­ed 77,000 NHS work­ers un­vac­ci­nat­ed, the gov­ern­ment de­cid­ed to back down.

Javid told the Health and So­cial Care Se­lect Com­mit­tee that it was right to “re­flect” on the pol­i­cy now that the Omi­cron vari­ant had sur­passed Delta, which was the dom­i­nant vari­ant when the pol­i­cy was ini­tial­ly an­nounced. The gov­ern­ment is now con­sid­er­ing re­mov­ing the vac­cine man­date for NHS work­ers.

Many who feel strong­ly that vac­cine man­dates are a breach of their hu­man rights will be re­joic­ing at this U-turn, but some peo­ple who are clin­i­cal­ly ex­treme­ly vul­ner­a­ble and may re­quire treat­ment from po­ten­tial­ly un­vac­ci­nat­ed NHS work­ers have been con­tact­ing me via so­cial me­dia to ex­press their dis­may at the de­ci­sion, with one say­ing that af­ter the UK had all but re­moved so­cial dis­tanc­ing mea­sures and mask-wear­ing, this was the “fi­nal straw” for her and she felt “aban­doned” by pol­i­cy­mak­ers.

I feel every­one of­fered the vac­cines should take them up, and I am triple vac­ci­nat­ed my­self, but I have al­ways main­tained that get­ting any med­ical in­ter­ven­tion, in­clud­ing the COVID-19 vac­cines, should be a choice. Tech­ni­cal­ly, the choice over hav­ing the vac­cines was not re­moved here, but the con­se­quences of not be­ing vac­ci­nat­ed meant po­ten­tial­ly be­com­ing un­em­ployed. The NHS is fac­ing what is prob­a­bly the most dif­fi­cult time in its his­to­ry, with a back­log of peo­ple need­ing treat­ment and staff suf­fer­ing from burnout. Los­ing 77,000 staff mem­bers would not be in the best in­ter­est of pa­tient care and would on­ly lead to fur­ther de­lays and added pres­sure on the vac­ci­nat­ed staff mem­bers left be­hind.

De­spite the U-turn, the ini­tial de­ci­sion to man­date vac­cines for NHS work­ers has caused con­sid­er­able stress to those who chose not to take up the vac­cines. I have spo­ken with one health­care as­sis­tant who was in tears af­ter re­ceiv­ing a let­ter from her hos­pi­tal telling her she faced dis­ci­pli­nary pro­ceed­ings and dis­missal if she did not take up the vac­cines as per gov­ern­ment guide­lines. She was so up­set by this that she took time off work due to the stress it caused. NHS em­ploy­ers were al­so put in a tough po­si­tion, forced in­to dif­fi­cult con­ver­sa­tions with their em­ploy­ees, who are of­ten al­so their col­leagues, that some­times had a neg­a­tive im­pact on their work­ing re­la­tion­ship.

Could all of this have been avoid­ed? In my opin­ion, yes. Of­ten those in ivory tow­ers make de­ci­sions with­out con­sult­ing those of us work­ing on the front line. Many of us know that forc­ing peo­ple to take up vac­cines on­ly serves to mar­gin­alise them fur­ther, and of­ten re-en­forces their be­lief that they are be­ing co­erced in­to hav­ing an in­ter­ven­tion they feel un­easy about for many rea­sons.

Ed­u­ca­tion has al­ways been key when it comes to vac­cines. Most peo­ple I have spo­ken to have read mis­in­for­ma­tion on­line about the vac­cines, and by hav­ing open and hon­est con­ver­sa­tions with them, we can pro­vide them with the cor­rect in­for­ma­tion so that they can make an in­formed choice. The vac­cines are not with­out their small risks, but the ben­e­fits they of­fer against se­ri­ous ill­ness from COVID-19 far out­weigh these risks and that is why I chose to take up mine.

COVID-19Health


Related articles

Sponsored

Weather

PORT OF SPAIN WEATHER

Sponsored