Annual doses of the coronavirus vaccine may be required to boost immunity, the chief clinical officer has said.
Dr Colm Henry said that Health Information and Quality Authority (Hiqa) studies into the subject of immunity had shown persistent levels of antibodies for six months, with some decline after that point.
The prospect of autumn boosters or annual vaccinations has already been raised in other jurisdictions, and Dr Henry said it “may well” be the case that they will be required here.
The news comes as HSE Director-General Paul Reid voiced his frustration over vaccine supply lines, with the first-quarter target now reduced to 1.1 million from an initial 1.7 million.
Dr Henry told the Oireachtas Health Committee: “Hiqa have surveyed the question of immunity, whether it’s natural or vaccine-induced immunity, and we do see that there’s evidence of persistent antibodies for up to six months, with some waning after.
“So the question for all countries for booster dose is one that’s outstanding internationally, and one that’s not answered yet.
“It may well be that we’ll be looking at annual doses depending on what the evidence shows in time.”
Last month UK Prime Minister Boris Johnson said autumn booster jabs may well be needed to fight the emergence of new variants.
The HSE website currently states that “the need for and timing of booster doses has not been established” and that no additional doses are recommended at this time.
Meanwhile, Mr Reid said issues over vaccine supply lines had arisen four times in the last three weeks.
Mr Reid said: “Our first quarter has been an experience of high levels of frustration on supply issues, to be frank, from the HSE’s perspective.
“Certainly Pfizer has been more stable, but we did have one change to their supply line. Moderna of late, unstable, and certainly AstraZeneca being unstable.
“It has been a very frustrating quarter overall for supply lines.”
Mr Reid noted it had been an EU-wide issue and that a “higher level of predictability” was anticipated in quarter two.
He said because around 175,000 doses scheduled for delivery in the first quarter will only arrive at the very end of March, the 1.2 million target will “probably drift into the first week of April”.
“So realistically we’re looking at about 1.1 million, probably going into 1.2 in the first week of April,” he added.
He said the HSE’s operating plan had changed between 15 and 17 times, either because of changes to supply, prioritisation, sequencing or the types of vaccines to be utilised.
He added: “We’ve adjusted every time to whatever the issue is, the supply chain issue or any of them. So the delivery of it is not impacted, to the end of the quarter from an efficiency or an operational perspective.
“The delivery of it, if it is to be impacted, will be impacted by supply.”
The HSE remains hopeful the supply issues will ease in quarter two, with 3.8 million doses targeted.
That figure includes 600,000 of the single-dose Johnson and Johnson vaccine, which is still subject to approval by the European Medicines Agency.
