Australians who receive the AstraZeneca vaccine have previously been told to wait 12 weeks between their first and second doses to maximise the jabs’ effectiveness.
However, greater Sydney’s worsening outbreak of the Delta variant of coronavirus has triggered a change of tune in the advice from health authorities.
New South Wales chief health officer, Dr Kerry Chant, is now pleading with anyone who has already received one dose of the AstraZeneca vaccine to talk to their doctor about cutting the interval period to six weeks. She said sacrificing “a bit of long-term protection” was warranted given the threat of the current outbreak.
If you live in greater Sydney, here’s everything you need to know about bringing forward your second AstraZeneca dose, what it means for immunity, boosters and availability.
Is the shorter interval advice for everyone?
The reduced interval only applies to people in greater Sydney, with the 12-week gap between doses still recommended for anyone outside that region.
This is because of the higher risk in greater Sydney with the virus circulating in the community. Chant said with the Delta variant, two doses were needed to protect most people against severe illness.
Chant stressed the importance of older residents in particular bringing forward their second dose given their increased susceptibility to severe illness from Covid.
She said elderly patients seeking to book vaccine appointments would be prioritised during the current outbreak.
At what stage should I get in touch with my GP to book an earlier appointment for my second dose?
Chant said as soon as four weeks had passed since the first dose, people should contact their GP to book a second dose, from six to eight weeks after their first shot.
If eight weeks had already passed people should contact their GP about bringing forward the second dose as soon as possible.
Where can I book an appointment for an earlier second dose?
Chant, along with the Royal Australian College of General Practitioners, has advised anyone in greater Sydney to first talk to their GP about bringing forward their second dose.
Earlier second doses can also be booked at state and federal-run vaccination clinics.
However, supply and booking availability issues have meant not every GP and vaccine hub participating in the rollout was in a position to bring forward appointments for second doses scheduled in the coming weeks, given the ongoing priority to administer first doses.
Sydney residents seeking to bring forward their second dose appointments to this week have told Guardian Australia they have been turned away by their local GP clinics. An RACGP spokesperson said that while some GPs in Sydney reported a surge in requests to bring forward second dose appointments on Monday, this was not the majority.
I want my second dose ASAP. Where do I have the best chance of booking it?
If you’ve tried calling your GP and they have said it’s fine to bring forward your second dose but that they don’t have availability, you have a few options.
The federal government’s vaccine eligibility checker is a good place to start, as this will show appointments at GPs, as well as state and federal clinics.
If you still haven’t been able to find an appointment, we’ve heard some people in Sydney have had success using the online GP booking website Hotdoc.
I still can’t seem to find a second dose appointment. What should I do?
There is a good chance booking availability may open up in the coming days, as vaccine supplies and new vaccination hubs come online in greater Sydney.
On Monday, the NSW government announced that its vaccination clinics would begin making the AstraZeneca vaccine available to people aged over 40, which should alleviate pressure on GP clinics.
However, Chant has stressed elderly residents would be prioritised for vaccine bookings in the state during the current outbreak, so your age might affect how easily you can bring forward your second dose.
I’m under 40 – how do I fit into all of this?
If you’re under 40, and not yet eligible for the Pfizer vaccine recommended for your age group, you’re able to talk to a GP about getting the AstraZeneca vaccine. If you do, you’re able to book your second dose in line with the shortened second dose interval window of six weeks that is now being encouraged in Sydney.
So there’s a trade-off here if I bring forward my dose. I know the government wants us to do this, but is this the right choice for me? Is it safe?
Guardian Australia’s medical editor, Melissa Davey, has read the research, spoken to the experts and written this comprehensive explainer about the effects of bringing forward a second dose, which you can read here.
In short, she writes that there is some concern that the shorter interval between doses will lead to less protection against the virus including variants, given the independent expert group Australian Technical Advisory Group on Immunisation advises that efficacy against symptomatic disease “ranges from about 62% to 73% with the higher efficacy seen after a longer interval” between doses.
But this efficacy is still fairly good when a second dose is given from around day 22 – about three weeks – after the first dose, at about 60%, Atagi said.
“Shortening the interval from 12 weeks to no less than four weeks between doses is acceptable and may be appropriate in certain circumstances, for example, imminent travel or anticipated risk of Covid-19 exposure,” the Atagi advice states.
How do booster shots play into this? Will they improve immunity for people who shorten their interval between AstraZeneca doses?
This is something authorities have pointed to as a way to reassure people concerned by a trade-off in long-term immunity.
On Monday, Chant said “clearly, having the vaccine within the six to eight weeks trades off the duration of protection that that vaccine might provide you but we know that into the future, we will be providing booster doses of various vaccines and what we want to do is protect you”.
The RACGP NSW chair, Associate Prof Charlotte Hespe, went further, saying GPs would probably look at which patients had brought forward their interval period between doses when looking to prioritise booster appointments once approved.
“We will definitely be looking at giving boosters for those who get it early,” she told Guardian Australia. “You will actually have a benefit from coming in early because we’ll keep you on that list.”
Is NSW’s advice here radical? Is this the first jurisdiction to administer the AstraZeneca vaccines with a shorter interval window than 12 weeks?
No, NSW is not the first here. In June, the UK made the decision to reduce the length of time between vaccine doses from 12 weeks to eight weeks because of the spread of the Delta variant.
