By Elizabeth Sitotombe
JUST as the world was calming down, with talk of COVID-19 variants dying down, a new version of the Delta variant has been discovered in the UK and is believed to be driving a surge in COVID-19 cases in the country.
AY.4.2, also called ‘Delta Plus’, is estimated to account for about 11 percent of cases in the UK and has now been classed as a Variant Under Investigation (VUI) amid concerns of its high transmissibity.
The Delta variant is more transmissible than the previous coronavirus strains.
According to WHO, the AY.4.2 has been discovered in at least 42 other countries, including India, Poland, Japan and Germany.
In Portugal, nine cases of the sub-variant have been detected.
Russia and Israel have also reported cases of the sub-variant.
As of October 20, there were 15 120 cases of the sub-variant detected in the UK and rising.
Of late, the UK has recorded one of the highest number of new cases in any country, only coming second to the US.
According to a senior researcher in the UK: “It is possible that the AY.4.2 variant will spread widely, the new variant could even replace Delta eventually, although the process is likely to be slow.”
What do we know about this variant?
AY.4.2 is a descendant of the Delta variant of SARS-CoV-2.
Scientists say AY.4.2 carries two characteristic mutations in the spike — Y145H and A222V— both of which have been found in various other coronavirus lineages since the beginning of the pandemic.
Reports from the UK indicate a ‘growth rate of 17 percent for AY.4.2 compared to other circulating variants’ and a ‘secondary attack rate’ of 124 percent for household contacts compared to 11,1 percent for Delta.
According to WHO epidemiological update, an increase in AY.4.2 sequence submissions has been observed since July 2021 while, as of October 25, over 26 000 AY.4.2 sequences have been uploaded to GISAID from 42 countries.
During a technical briefing, the UK Health Security Agency said the AY.4.2 had a modestly increased transmissibility rate in comparison to Delta and this could be due to a biological mutation in the virus or to epidemiological context, such as being introduced into an area or population subgroup with high existing levels of transmission.
Should we be concerned about AY4.2?
Scientists across countries, including South Africa, have agreed that this variant is more infectious.
However, neither of the mutation Y145H and A222V is in the receptor binding domain, which is the part of the spike that binds to a particular receptor on humans’ cells to affect them, thus suggesting that the mutations are unlikely to cause a major increase in transmissibility or help the virus evade the immune system.
In an interview with CNBC, Christina Pagel, director of the Clinical Operational Research Unit at University College of London said: “Delta compared to Alpha was around 60 percent more transmissible, it was doubling every week.
This is going up by a percent or two per week – it is much, much slower.
So, in that sense, it is not a big disaster like delta was.
It will probably replace Delta over the next few months. But there is no sign it’s more vaccine-resistant, so at the moment I wouldn’t be panicking about it.”
The variant needs to be monitored and carefully controlled.
Are vaccines effective against this variant?
According to scientists, it is unlikely that the Delta Plus variant can evade all vaccine-related immunity.
There is no evidence that the sub-lineage AY.4.2 impacts the effectiveness of our current vaccines or therapeutics.
Vaccinations offer a high level of protection against severe illness with COVID-19.
Although COVID-19 infections have been rising again across the UK, the number of hospitalisations and deaths has remained well below the levels seen in earlier waves, and experts attribute this success to the vaccination programme.
To date, 240 million cases and more than 4,9 million deaths have been recorded across the globe.
Zim and a looming Fourth Wave
According to health experts, the dreaded Fourth Wave might hit the country by year-end and will likely be, ‘more serious’.
As of October 31 2021, Government had vaccinated 38 percent of the target 60 percent against COVID-19.
Government recently announced the vaccination of teenagers aged 16 and 17 as specialist pediatricians recommend the Sinovac COVID-19 vaccine.
The country remains under Level Two Lockdown and, in view of a potential Fourth Wave, the public is urged to continue to exercise caution.
Wearing a mask, avoiding less ventilated areas, sanitising and, above all, getting vaccinated is the way to go.
As long as there are unvaccinated people, the virus will continue to evolve.
Let us all be responsible.