Concern as new BA.2.75 variant of Omicron poses risk of winter wave

Keeping watch

The current wave is fuelled by the BA.5 and BA.4 version of Omicron.

It followed BA.1 and BA.2 which caused a major rise in infections earlier this year.

Now, there is increasing worry around another member of the Omicron family, BA.2.75, although there is also caution around causing false alarm.

It has been found in around 10 states in India.

A small number of cases have been sequenced in some other countries so far including the UK, Canada, the US, Japan, Germany, Australia and New Zealand.

Reasons to worry

There are several strong reasons to keep this under close watch and investigate if it will be the variant behind another autumn or winter surge.

As we know from bitter experience in Ireland, when a new sub-lineage of Omicron evolves it is more infectious.

New variants have come and gone but new offsprings of Omicron have staying power.

If BA.2.75 is not the next one to cause trouble, the manner in which the second-generation Omicron versions are evolving suggests another will.

The data on BA.2.75 is limited so far but the basis for concern is that this version of Omicron could have more mutations beyond BA.5 which would make it better at attaching to human cells.

It could make it easier to get around immunity from previous infection and vaccination.

Thomas Peacock, a scientist at Imperial College in London, said the variant is worth “keeping a close eye on”.

More severe

The big question is whether it is more severe and capable of making people who catch it very sick.

More investigation is needed but we already know Omicron is less severe than previous strains because it is less likely to attack the lungs, and targets the upper airways more.

While keeping vigilant of a potential new enemy down the tracks, the BA.5 and BA.4 summer wave here continues to cause a rise in infections, although there are signs the pace is slowing.

Signs of hope

The positivity rate for people taking PCR tests yesterday fell to 39.5pc compared to 41.02pc last Friday. However, the seven-day positivity rate is up from 36.2pc to 37.3pc.

This week and next will tell a lot but the incline could be slow. There is also some hope to be drawn from admissions of Covid-19 patients to hospital. There were 885 Covid-19 patients in hospital yesterday morning, up from 826 on Sunday but this rate of admission also looks like slowing.

The number of patients with Covid-19 in intensive care remains stable at 33.

It continues to infect and re-infect causing disruption to the workplace which is not on the scale of the BA.2 wave earlier this year, but still akin to regular winter respiratory infections and flu.

Based on the experience in Portugal, which was the first country in Europe to see this wave, it will take time before this wave substantially subsides. It means Ireland could soon be over the worst but burdened by a leisurely drop in infections and hospitalisations.

It could mean a relative reprieve for much of August allowing time for hospitals to make inroads into waiting-list backlogs and for the general population to be at reduced risk of infection.

It will also allow for planning to roll out more booster shots in the autumn and hopefully for businesses to plan around the kind of hybrid working they envisage during the autumn and winter months, as well as hospitality and entertainment venues to invest in ventilation systems before the great migration indoors again.

Other threats

Covid-19 will be a dominant infectious disease threat for some time to come but increasingly, focus is also on the emergence of other viruses. The monkeypox virus will have to be handled in the coming months along with the standard winter risks.

A new report from the Health Protection Surveillance Centre yesterday found a shift in seasonality in respiratory syncytial virus (RSV) affecting children last summer and throughout 2021 and 2022. It began early in July and August compared to previous seasons when an increase would be seen in October.

It came to an early end in January this year, compared to previous seasons when it would normally have plateaued at the end of February. The normal seasonality was interrupted in 2020 due to factors such as the closure of childcare facilities which reduced its circulation.

The early resurgence in the summer of 2021 followed a relaxation of public health measures and personal behaviours. It points to the need for continued surveillance and close monitoring of RSV throughout the summer to determine if Covid-19 has changed its pattern of spread.

Meanwhile, it was announced yesterday that Ireland is expected to get more vaccines to prevent monkeypox which has so far led to 39 cases here.