A “MODEST” CHANGE in people’s behaviour over the coming weeks would enough to “shift the balance” in transmission of Covid-19 in Ireland, according to a member of NPHET.

Prof Philip Nolan, who is also chair of the NPHET Irish Epidemiological Modelling Advisory Group, said the balance had “tipped in the wrong direction” but that change in behaviour would bring down the reproductive number of the virus, below 1.0, and start to suppress it once again.

The total number of cases in the past seven days have been up around a third on the previous week with public health officials confirming 2,180 new cases earlier today. 

There is also worry from the HSE about Ireland’s position as it heads into the winter, with fewer than 10% of the adult population unvaccinated, but those who have not been vaccinated make up about half of those hospitalised with Covid-19. Two- thirds of those are in ICU.

Nolan said on Twitter today that Ireland had been left in a “vulnerable position” following the vaccination of 16-30 year-olds in the summer, with high levels of infection still present among younger age groups while “increasing levels of social contact” were beginning to take place. 

“…This left us in a vulnerable position, with high levels of infection, and that delicate balance between very high levels of vaccine protection on the one hand, and increasing levels of social contact and risk of transmission on the other.

The increase over the last 10 days shows that this balance has tipped in the wrong direction: with high levels of circulating virus even a subtle change in the scale or nature of social contact can significantly shift the dynamics of viral transmission in the population. 6/16

— Professor Philip Nolan (@PhilipNolan_MU) October 16, 2021

“The increase over the last 10 days shows that this balance has tipped in the wrong direction: with high levels of circulating virus even a subtle change in the scale or nature of social contact can significantly shift the dynamics of viral transmission in the population.”

Nolan added: “This also means that a relatively modest adjustment in our individual and collective efforts to reduce risk of transmission should be enough to shift the balance in the opposite direction, bring effective reproduction number below 1.0 and start to suppress the virus again.”

Increasing infections

On why infections have been increasing, Nolan said this was complex but cited an increase in mixing indoors along with increased social contact.

He added that NPHET “do not believe [the rising case numbers are] connected to the reopening of schools”, citing a decrease in incidence in schoolchildren.

However, health officials do have data from the Economic Social Research Institute (ESRI) Social Activity Measure that mobility and social contact are increasing, Nolan said.

“A shift from outdoors to indoors may be playing a role,” he continued.