Explainer - The arrival of the Omicron variant of Covid-19 into New Zealand has meant the gap between the second vaccine dose and booster has been shortened even further - originally six months going to four months in early January 2022, and then reduced to three months in early February.
Photo: RNZ / Angus Dreaver, Nick Monro / AFP
The timing of the rollout had previously caused some confusion about when people should go and how it all works.
The government made its latest decision on the interval after advice from the Vaccine Technical Advisory Group. It meant more people would be able eligible to get their booster before Omicron took hold in the community.
There's also a difference between booster doses and third primary doses. (Note: For most people, a primary course is two doses, for some people a primary course could be three doses.)
RNZ is here to clear it all up.
What is the booster dose?
The Pfizer booster vaccine dose is generally being used in New Zealand, even if you had a different vaccine for your primary course.
AstraZeneca boosters are also available on prescription, but only four months after the second dose. Prescriptions can be obtained at the vaccinating AstraZeneca clinic or before the vaccine appointment with a doctor. It is free to visit the doctor for an AstraZeneca booster prescription.
The booster is different to the third primary dose recommended for people who are immunocompromised.
People eligible for a third primary dose can access a booster dose three months after receiving their third primary dose.
When can you get your booster?
In early December, the government announced it would shorten the required gap between the second dose and booster, from six months to four months. In early February, the interval was further reduced to three months, or 93 days.
You can check when you are due for a booster by visiting mycovidrecord.nz or your purple Covid-19 Vaccine appointment card if you have one.
If you have already booked your booster dose with a four-month gap, you can keep your original appointment, or change it. Although, the government has advised people not to delay getting it, to reduce the risk of Omicron as it spreads in the community.
The Ministry of Health has said there are plenty of booster doses available and no one would miss out.
Where to go to get a booster
You can find locations for walk-in and drive-through vaccination places by clicking here.
Appointment slots have been available from 17 January via Book My Vaccine online.
If you cannot book online, you can call the Covid-19 Vaccination Healthline on 0800 28 29 26 (8am to 8pm, seven days a week).
Interpretation services, and text, email and NZ Relay options for deaf and hearing impaired are available if you need them via the 0800 number.
There is also a specialist team for disabled people (option 2 on the 0800 number).
You can also make an appointment with your doctor if they are providing Covid-19 vaccines.
Who is eligible for the Covid-19 vaccine booster?
Healthcare and border workers have been the priority for booster doses since large numbers of people in those industries had their primary doses earlier than the rest of the population.
When you arrive for your booster, the date of your last dose will be checked in the booking system to ensure you have gone through the required interval period.
People aged five years and older have been able to get their primary Covid-19 vaccine courses, but the booster dose is currently only available for those aged 18 years and above.
Advice from the Covid Vaccine Technical Advisory Group is expected in mid-February on when 12 to 17 year olds would be able to get booster doses "if the scientific advice supports booster doses in some, or all, of this age group", the government said on its Covid-19 website.
The booster vaccine can be given at any stage of pregnancy, at least 3 months after the primary course.
In a pamphlet from the ministry early in December, the ministry had recommended that those who had their full primary course during pregnancy to wait until after the baby is born to get the booster dose. However, in a statement to RNZ on 7 January, the ministry has clarified that advice has changed for pregnant women following review from the College of Obstetricians and guidance issued by the Australian Technical Advisory Group on Immunisation.
"Pregnant people are at high risk for severe outcomes from Covid-19 infection, and those who are unvaccinated are more likely to have complications during pregnancy if they contract Covid-19," the ministry said in a media release.
The ministry advised that pregnant women should discuss the timing of their booster with their midwife, obstetrician or general practitioner.
If you had your Covid-19 vaccination overseas, you can get still get the booster for free once you have gone through the required interval from your last dose.
Potential side effects of boosters
You may experience some side effects with the booster similar to the primary course of the vaccine, according to the Ministry of Health.
These include muscle aches, pain at the injection site, headaches, nausea, and feeling tired or fatigued. For most people, these tend to be mild effects and don't last long.
Read more: Mythbusting booster recovery tips
Some side effects are more serious but very rare, like a severe allergic reaction or an inflammation of the heart (myocarditis). You can find out more on the different serious side effects from Pfizer and AstraZeneca's Covid-19 vaccines by clicking here.
If you develop difficulty breathing, a racing heart, chest pain or feel faint immediately or in the days after the vaccine, you should seek medical attention.
If you're unsure about your symptoms or if they get worse, call Healthline: 0800 358 5453.
If you have had a severe or immediate allergic reaction to any vaccine or injection in the past, tell your vaccinator. Serious allergic reactions do happen but are extremely rare.
An online reporting form for adverse events following immunisation with Covid-19 vaccines is now available.
Director-General of Health Ashley Bloomfield said New Zealand Covid-19 vaccination data so far was similar to that overseas; we had not seen an increase in side effects, and overall adverse events after each additional vaccination had declined.
Vaccine passes for boosters
You do not need to have a booster to be certified as 'fully vaccinated' for My Vaccine Pass or an International Travel Vaccination Certificate. Your My Vaccine Pass will remain valid, even if you do not get a booster dose.
If you do get a booster dose, it will be added to My Covid Record and you can create another pass.
Is it mandatory to have a Covid-19 vaccine booster?
Early in December, the government announced Cabinet agreed in principle that where workers are required to be vaccinated, this mandate will now extend to booster doses.
The addition to the order came into effect on 23 January 2022 and means border and MIQ workforces, health and disability workforces, as well as those involved with the border or health or MIQ from Corrections, police, defence, and fire and emergency will be required to have their booster by 15 February, 2022, if eligible.
For police and fire and emergency workforces who are involved with education, they are required to have the booster by 1 March 2022. The same date applies for the education workforce.
For all these workers, a booster dose is mandated six months (183 days) from the end of their primary vaccination course. Although, as with the rest of the eligible population, they will also be eligible for a booster three months after their primary vaccine course.
How effective is the booster against Covid-19?
The Ministry of Health said data from Pfizer showed that a booster dose was 95.6 percent effective against the coronavirus, including the Delta variant, compared to those who did not receive a booster.
The ministry said evidence showed that after six months of a full vaccination course, protection against Covid-19 was reduced and so a 'top up' vaccine would help boost immunity against the virus.
"We already know that booster vaccinations significantly lift an individual's immunity, reducing the spread and the severity of Covid-19.
"Data is emerging now that booster doses of Pfizer provide better protection than two doses do when it comes to the Omicron variant."
The UK Health Security Agency (UKHSA) analysed more than 600,000 confirmed and suspected cases of the Omicron variant up to 29 December in England and found a booster vaccine is 88 percent effective at preventing people ending up in hospital with Covid-19.
The data confirms that two doses of the AstraZeneca, Pfizer or Moderna vaccines offers little protection against being infected with Omicron.
Why has the time between the second dose and booster been shortened?
Before the highly infectious Omicron variant arrived in the community, Covid-19 Response Minister Chris Hipkins had said it was expected that every case coming into New Zealand's border would be of the variant.
The government hopes having widespread administration of the Covid-19 vaccine booster will help decrease the risk of transmission and minimise the impact on the healthcare system.
"Don't think getting a booster is just about keeping yourself safe," said Prime Minister Jacinda Ardern. "It's about ensuring our hospital and health system is not overwhelmed so those you love and everyone in our community who needs our hospitals can get the care they need."
Hipkins said the change in interval would give a chance for people, especially Māori, to receive a booster and increase their protection before Omicron took hold.
Ministry of Health Chief Science Advisor Ian Town said bringing it forward to three months, which had been done in the United Kingdom and in many Australian states, meant New Zealand could get the level of antibodies at a peak before it was facing widespread transmission of Omicron.
There did not appear to be any downside to reducing the interval to three months, he said.
Director-General of Health Dr Ashley Bloomfield said speeding up the booster rollout was a key part of the country's response to Omicron.
*This story was updated on 7 January, 2022, 18 January, 2022, and 7 February, 2022 as per Ministry of Health updates and government decisions.