COVID testing in New Zealand: What you need to know

For people who are unvaccinated, health professionals or businesses who need to test employees frequently, rapid antigen tests (RATs) offer a convenient alternative to community testing centres. But how do RATs compare to RT-PCR testing, how effective are they and how long you have to wait for a result? Also, is it accepted for travelling to New Zealand or needed when leaving the country?

To answer these questions, we spoke to two experts in this field: Dr Larisa Labzin, an IMB fellow and NHMRC CJ Martin fellow at the Institute for Molecular Bioscience at The University of Queensland; and Mimi Ho, clinical supervisor and policy advisor (Rapid Antigen Test & Rapid Antibody Test) at Global Healthworkz.

Here’s everything New Zealanders need to know about COVID rapid antigen testing under the current rules.

What is a rapid antigen test?

Rapid antigen tests, also known as RATs, are essentially a screening tool that helps detect COVID-19 in people without any symptoms (asymptomatic) or to regularly monitor infection for high-risk people.

The test involves collecting a saliva sample or nasal swab and placing it into a chemical solution. “How it works is sort of similar to a pregnancy test,” Dr Labzin told Finder. “Essentially our immune system makes antibodies that are specific to different viruses. So if you’ve got some of that antigen present, the test will recognise it and alert you with a colour change.”

The main benefit of a RAT is that you can see the results within 30 minutes. Another benefit is that the test only requires putting a swab partway up your nose, rather than down your throat.

“With some rapid antigen testing kits, you don’t have to put a swab in your throat because the particles still exist in our saliva,” explained Mimi Ho. “You just expel a few drops on the test case itself. The test case will be able to detect whether we have the virus or not.”

Here’s a video demonstration of a testing kit:

Disclaimer: For information purposes only. Tests may be different.

How do rapid antigen tests differ from RT-PCR tests?

A rapid antigen test is designed with speed and simplicity in mind. In short, it delivers quick results. By contrast, a Reverse Transcription Polymerase Chain Reaction (RT-PCR) test requires a medical professional and needs to be sent to a lab for analysis. Results can take 48 hours or longer in some cases.

“[Rapid antigen testing] is good because it’s quick and rapid but there are issues around the specificity of it so the chances of getting a false negative are higher,” Dr Labzin explained.

“Now that we’re moving towards a ‘living with COVID’ scenario instead of zero cases, they have a lot more use.”

Rapid antigen test vs PCR test

Here are the main differences between PCR tests (the type you receive at clinics) and rapid antigen tests (the type that are available for on the spot testing).

Nucleic acid-based testing (PCR tests)

Molecular or nucleic acid-based tests (also known as PCR tests) are the most accurate way to test for COVID-19 and are usually carried out by specialised laboratories.

• How it works. It detects the presence of SARS-CoV-2 genetic material (RNA) in respiratory samples to determine if COVID-19 is present.
• What it tests. It tests for a current COVID-19 infection (usually within 1-2 days).
• How samples are collected. Samples are collected through a nose, throat or oral swab.
• How long it takes. It usually takes 1-2 days to process the results.

Antigen-based testing (rapid tests)

Antigen tests are rapid COVID-19 tests that produce quick results when you test for COVID-19 at a doctor’s office, pharmacies or in workplace/academic settings.

• How it works. Samples are placed in an extraction buffer or reagent and tested for the presence of SARS-CoV-2-specific virus proteins (also called antigens).
• What it tests. It tests for a current COVID-19 infection (usually within 15 minutes).
• How samples are collected. Samples are collected through a nose, throat or oral swab.
• How long it takes. It usually takes 15 minutes to an hour to process the results.

How much does rapid antigen testing cost in New Zealand?

COVID-19 supervised rapid antigen testing is available for free in New Zealand at participating pharmacies for unvaccinated asymptomatic people who are required to show a negative RAT for domestic travel during the core summer period.

Businesses wishing to test employees beyond mandatory community testing will have to pay for RATs themselves.

These are the four rapid antigen tests that have been approved by the Ministry of Health:

• SARS-CoV-2 Rapid Antigen Test
• PanBio COVID-19 Ag Rapid
• CareStart COVID-19 Antigen
• CLINITEST® Rapid COVID-19 Antigen Test

What are the current rules surrounding rapid antigen testing?

In an effort to ease the pressure being felt by the healthcare system due to massive testing demands, the government is introducing RATs to support the pandemic response. RATs do not replace vaccination, PCR testing, mask wearing, social distancing or washing of hands.

Currently rapid antigen tests are being used for:

• unvaccinated people travelling domestically
• those in high-risk settings , e.g. hospitals
• point of arrival travellers from overseas
• returnees from managed isolation facilities
• businesses requiring additional testing

Rapid antigen tests and overseas travel

RAT tests are not accepted for travel into New Zealand. A negative PCR test is required within two days of inbound travel to New Zealand. In terms of departing New Zealand, you currently don’t need to provide a negative PCR test at check-in to meet requirements.

However, some countries and airlines do require a pre-departure PCR test result before you will be allowed to board, so make sure to do the necessary research before any trip.