With COVID-19 still circulating and flu season hitting hard in Australia, Rapid Antigen Tests (RATs) remain an important line of defence — whether for home use, workplace screening, or clinical settings.
But did you know that not all RATs test for the same thing?
There are now multiple types of tests available:
- COVID-only tests
- 3-in-1 tests (COVID + Flu A and B)
- 4-in-1 tests (COVID + Flu A and B+ RSV)
- 5-in-1 tests (COVID + Flu A and B+ RSV+ ADV)
Let’s dive into each type and help you choose the best one for your needs.
What Is a Rapid Antigen Test?
A Rapid Antigen Test (RAT) is a quick diagnostic test that detects specific proteins (antigens) from the surface of a virus — such as SARS-CoV-2 (COVID-19). These tests are designed for self-use and provide results faster than traditional laboratory tests like PCR.
Important thing to Note:
RATs don’t just randomly detect “any virus” — they only detect the specific virus they are programmed to look for.
So:
- A COVID test looks for the antigen of the COVID-19 virus (SARS-CoV-2).
- A Flu test looks for influenza virus antigen.
- A combined test can look for multiple viruses at once (Influenza A/B+COVID-19)— but only if it’s designed that way.
How do they do that?
They use special antibodies that are designed to find and attach specific viral antigens — unique proteins found on the surface of a virus.
- If the virus is present in your sample, the antibodies bind to its antigen, triggering a chemical reaction that produces a visible line on the test strip (positive result).
- If the virus isn’t there, there's no binding, and the test shows negative.
Types of COVID-19 Rapid Antigen Tests
Different RAT kits vary not just in format (e.g. nasal swab vs saliva), but also in the number of viruses or infections they test for. That’s where the "in-1" terminology comes in.
| Type | What It Detects | Best For |
| COVID-19 Only | Detects COVID-19 only | Simple cases of suspected COVID exposure |
| 3-in-1 | Detects COVID-19 + Influenza A/B | Cold & flu season, unsure if symptoms are COVID |
| 4-in-1 | Detects COVID-19, Flu A/B, and RSV | Families with babies, elderly, or high-risk |
| 5-in-1 | Detects COVID-19, Flu A, Flu B, RSV, ADV | Advanced home care, aged care, or school settings |
COVID‑19 Only Tests
Why it still matters now
COVID‑19 activity is currently moderate, with hospital admissions rising in recent weeks Booster uptake in Australia has slumped (only ~6% in the past six months), and a new subvariant NB.1.8.1 is spreading fast.
Best for:
People who simply need to know if they have COVID‑19, especially:
- Those showing COVID‑specific symptoms (e.g. loss of taste/smell)
- Individuals over 65 or with pre‑existing conditions, to decide about boosters or treatment
- People preparing for travel or returning to work
What to think about:
COVID‑only tests are the most affordable and give fast results. They're great if you're confident it’s COVID and not another virus. But they won’t detect flu or RSV, which are currently spreading too.
3‑in‑1 Tests: COVID + Flu A/B
Why it makes sense now
Australia is seeing a record surge in flu, with over 80,000 cases by May, driven mostly by children. Flu notifications have outpaced COVID in many regions. Vaccination rates are low (only ~25% of Aussie adults, and even less in children) .
Best for:
- Parents and families during flu season
- Anyone wanting to know if a fever or cough is flu or COVID
- People in schools, workplaces, or care settings
What to think about:
More cost than a single COVID test, but helps avoid unnecessary isolation if it’s just flu. Smart choice for clarity and convenience.
4‑in‑1 Tests: COVID + Flu A/B + RSV
Why it fits now
RSV is currently high across NSW and Queensland. In QLD alone, there have been 14,600+ cases and 1,724 hospitalisations in infants this year.
Best for:
- Parents with young children or babies
- Aged‑care and childcare providers wanting wider coverage
- Households with both the young and elderly present
What to think about:
More expensive but offers strong peace of mind knowing RSV is covered—especially when infants or grandparents are at home.
5‑in‑1 Tests: COVID + Flu A + Flu B + RSV + ADV (Adenovirus)
Why it’s relevant
Adenovirus (ADV) isn’t making headlines, but it’s a known culprit behind respiratory illnesses, especially in kids. With Sydney and Melbourne currently seeing high cases of flu, RSV, and COVID, having a broad-spectrum test helps reduce guesswork and risk.
Best for:
- Large families, especially with kids or elderly
- Residential care, school camps, or communal living environments
- Those wanting the most detailed and proactive health check
What to think about:
It’s the priciest option, but if you’re facing multiple potential infections—especially during winter—it’s the ultimate one‑swab answer.
Choosing the Right Test: What Matters?
- When deciding which Rapid Antigen Test to buy, here are some important factors to think about:
- Symptoms – If you only suspect COVID, a single test may be enough. But if symptoms are flu-like or affect multiple people, a multi-virus test is better.
- Who’s in your home? – If you live with babies, elderly parents, or high-risk individuals, choose a test that also includes RSV.
- Your budget – COVID-only tests are cheaper, but multi-infection kits offer more value by avoiding uncertainty and extra appointments.
- Environment – If you work in healthcare, education, or community care, multi-detection kits are recommended for quick and accurate triage.
- Peace of mind – If you want to make the most informed decision quickly, a 3-in-1, 4-in-1 or 5-in-1 test offers extra peace of mind.
Where Can I Buy These Tests in Australia?
You can find a wide selection of COVID-19 RAT kits, including multi-virus detection kits, on MedCart’s Rapid Test Page. We offer:
- ARTG-listed test kits
- Bulk packs for workplaces or events
- Free shipping options for select orders
FAQs
Are multi-infection RATs approved in Australia?
Yes, but only if ARTG listed. Always check the ARTG number to confirm it’s TGA-compliant.
Can I use a 5-in-1 test at home?
Yes, if it's a self-test version. Some multi-diagnostic tests are intended for professional use only, so check the label.
Do these tests work on asymptomatic people?
They are most effective when symptoms are present. However, some may still detect viruses in asymptomatic carriers — check the product label.
References
- Therapeutic Goods Administration (TGA) Australia. www.tga.gov.au – Accessed July 2025
- Department of Health Australia – COVID-19 Testing Guidance. Updated June 2025
- CDC – Understanding Antigen Tests for COVID-19 and RSV. June 2025
- WHO: Antigen-detection in the diagnosis of SARS-CoV-2 infection. March 2023
⚠️ Disclaimer:
This article is for informational purposes only. Always follow instructions provided with the test kit. For medical concerns, consult a healthcare professional.
