The HSPC says than half of the deaths in that period as a result of Covid were unvaccinated.
34 percent of the Covid-19 related deaths in Ireland between April and the start of last month were fully vaccinated people.
Figures from the HPSC also show 70 percent of ICU admissions hadn't been vaccinated at all, and 20 percent were fully vaccinated.
Ben Finnegan reports:
"Between April 1st and September 1st this year there were 301 deaths in people who were Covid-positive.
Of those 103 - or 34% - were fully vaccinated, while 45 - or 15 percent - had received at least one jab.
The Health Protection Surveillence Centre figures show more than half of the deaths in that period as a result of Covid were unvaccinated.
In those people who were fully vaccinated and died, there were 58 men, and 45 women - while the youngest was 50 and the oldest - 97.
And 62 percent of those had an underlying condition.
In terms of ICU admissions during the same period 70 percent hadn't been vaccinated at all, and 20 percent were fully vaccinated.
There were 356 admissions in total.
In the patients who were fully vaccinated and admitted to ICU - 97 percent had an underlying condition - and a third passed away.
The youngest fully vaccinated person admitted was 30 and the oldest was 88."