COVID-19 vs Flu vs RSV vs Adenovirus: Symptoms, Differences and 5-in-1 Respiratory Testing

Fever, cough, sore throat, nasal congestion and fatigue are common symptoms of respiratory infections. The challenge is that COVID-19, influenza A, influenza B, respiratory syncytial virus (RSV), adenovirus and other respiratory pathogens can cause similar symptoms.

So how can they be distinguished?

In many cases, symptoms alone cannot reliably identify the specific pathogen. Several respiratory viruses can circulate at the same time, creating overlapping clinical presentations and making respiratory testing an important part of surveillance and, where appropriate, individual assessment. ECDC's European respiratory virus surveillance framework specifically monitors influenza, SARS-CoV-2 and RSV as major respiratory viruses circulating in the EU/EEA, while also recognizing other respiratory pathogens such as adenoviruses.

For healthcare providers, pharmacies, diagnostic companies and IVD distributors, this creates a practical question:

Can one respiratory test detect several common pathogens from a single specimen?

A multiplex respiratory antigen test is one approach.

Why Are COVID-19, Flu, RSV and Adenovirus Difficult to Distinguish?

Respiratory infections often share common symptoms.

A person experiencing:

• fever

• cough

• sore throat

• nasal congestion

• fatigue

could potentially have influenza, COVID-19, RSV, adenovirus or another respiratory infection.

ECDC has highlighted the co-circulation of multiple respiratory pathogens in Europe and the resulting pressure on healthcare systems. Its current integrated respiratory-virus surveillance approach covers influenza, SARS-CoV-2 and RSV, while broader respiratory surveillance also considers additional viral pathogens.

This leads to an important diagnostic principle:

Similar symptoms do not necessarily mean the same pathogen.

Testing can therefore provide additional information when pathogen identification is relevant to the intended clinical or testing context.

COVID-19 vs Flu vs RSV vs Adenovirus: Key Differences

This comparison is intended for general education. Symptoms vary between individuals and cannot by themselves establish which pathogen is responsible.

ECDC's surveillance work demonstrates why multiple respiratory pathogens need to be considered together rather than viewed in isolation.

1. SARS-CoV-2 — The Virus That Causes COVID-19

SARS-CoV-2 is the virus responsible for COVID-19.

Respiratory symptoms associated with COVID-19 can overlap with those of influenza, RSV and other respiratory infections. This overlap means that symptoms alone may not always distinguish COVID-19 from another respiratory infection.

ECDC continues to include SARS-CoV-2 as one of the core pathogens in its integrated respiratory-virus surveillance system for Europe.

For respiratory diagnostic manufacturers and healthcare businesses, SARS-CoV-2 remains an important target within multiplex respiratory testing strategies.

2. Influenza A

Influenza A is one of the major influenza virus types responsible for seasonal influenza.

Common symptoms can include:

• fever

• cough

• sore throat

• fatigue

• headache

• muscle or body aches

Influenza viruses remain a central component of ECDC's European respiratory-virus surveillance programme. ECDC's surveillance framework integrates epidemiological and virological information on influenza and other respiratory viruses to support public-health decision-making.

Rapid antigen testing is one available approach for influenza detection, alongside molecular methods.

3. Influenza B

Influenza B can produce symptoms that are similar to influenza A.

Because the symptoms of influenza A and influenza B overlap, a test that distinguishes both types can provide more specific information than a generic influenza result.

Including Influenza A and Influenza B in the same panel therefore expands influenza coverage without requiring separate tests for each type.

4. Respiratory Syncytial Virus — RSV

RSV is an important respiratory virus that can cause illness across different age groups.

Common symptoms may include:

• runny nose

• nasal congestion

• cough

• fever

• wheezing

RSV is specifically included in ECDC's integrated European respiratory-virus surveillance system because of its public-health relevance and circulation alongside other respiratory pathogens.

The overlap between RSV symptoms and other respiratory infections is one reason that pathogen-specific testing may be useful in appropriate circumstances.

5. Adenovirus

Adenoviruses are a group of viruses associated with a variety of clinical presentations.

Some adenovirus types can cause respiratory infections characterized by:

• fever

• sore throat

• cough

• congestion

Adenoviruses may also cause other syndromes depending on the virus type and affected body system.

ECDC has identified adenovirus among respiratory pathogens that may circulate alongside other respiratory viruses, although adenovirus is not part of the same core routine surveillance group as influenza, SARS-CoV-2 and RSV in the EU/EEA.

This distinction is important: not every respiratory pathogen is monitored through exactly the same surveillance system.

Can One Nasal Swab Test for Multiple Respiratory Viruses?

Yes.

A multiplex respiratory test is designed to detect multiple pathogen targets from the same respiratory specimen.

Instead of:

One specimen → one pathogen

a multiplex test uses:

One specimen → multiple pathogen targets

ECDC's current respiratory surveillance framework reflects the fact that multiple viruses can circulate simultaneously across Europe. Integrated surveillance combines information from different sources to provide a broader picture of respiratory-virus activity.

At the diagnostic-product level, multiplex testing applies the same broad concept: multiple targets can be incorporated into one testing panel.

What Is a 5-in-1 Respiratory Antigen Test?

A 5-in-1 respiratory antigen test is a multiplex rapid test designed to detect five respiratory pathogen antigens within one test panel.

The BioTeke 5-in-1 Multiple Respiratory Multipathogen Antigen Test Kit targets:

SARS-CoV-2 + Influenza A + Influenza B + RSV + Adenovirus

BioTeke specifies human anterior nasal swab specimens, a lateral-flow immunoassay (LFIA) format and a 15–20 minute time to result. The product is listed by BioTeke as an EU IVDR CE-marked self-test under EU Regulation 2017/746.

Five Pathogens. One Test Panel.

The product combines five respiratory targets that can be associated with overlapping respiratory symptoms:

1. SARS-CoV-2

2. Influenza A

3. Influenza B

4. RSV

5. Adenovirus

This allows the five targets to be evaluated within a single testing workflow.

How Does the BioTeke 5-in-1 Test Work?

BioTeke's product uses a lateral-flow immunoassay based on an immunochromatographic double-antibody sandwich method.

The intended specimen is an anterior nasal swab. After specimen treatment according to the product instructions for use, the sample is applied to the test cassette. The assay is designed to detect antigen from the five targeted respiratory pathogens and generate the corresponding test signal.

The workflow can be simplified as:

Anterior nasal swab

↓

Sample preparation

↓

One multiplex test cassette

↓

Five pathogen targets

↓

Results in 15–20 minutes

This workflow is particularly relevant to decentralized settings where rapid testing and a simple operational process are important considerations.

Why Test Five Respiratory Pathogens in One Panel?

The key value of multiplex testing is broader coverage within a single testing event.

Consider a person presenting with fever and cough.

Potential causes include:

COVID-19

Influenza A

Influenza B

RSV

Adenovirus

A single-target test evaluates only one possibility.

A five-target panel evaluates all five targets included in the assay.

This does not mean that every respiratory illness is caused by one of these five viruses. Rather, it provides broader coverage of the specific pathogens included in the test.

For distributors and healthcare businesses, that broader coverage can make the product proposition easier to understand:

One test panel. Five respiratory pathogen targets.

5-in-1 Respiratory Test vs Separate Single-Target Tests

A multiplex panel can also simplify how a respiratory testing portfolio is presented.

Separate testing approach

COVID-19 test

• Flu A test

• Flu B test

• RSV test

• Adenovirus test

Multiplex approach

One 5-in-1 respiratory test panel

The operational advantages will vary by setting, test design, regulatory requirements and procurement model. However, multiplex testing can reduce the need to manage multiple separate test formats when the same five targets are required.

This is particularly relevant for:

• pharmacies

• primary-care settings

• diagnostic distributors

• healthcare businesses

• retail healthcare channels

• respiratory-testing programmes

Antigen Testing vs Molecular Testing

A five-target antigen test and a molecular respiratory panel are different technologies.

Antigen Testing

Antigen tests detect pathogen proteins.

Typical characteristics include:

• rapid results

• relatively simple workflow

• potential use in decentralized environments

• no need for complex molecular amplification equipment

The exact performance depends on the specific assay.

Molecular Testing

Molecular methods detect pathogen genetic material.

They are generally more analytically sensitive than antigen tests, but may require more complex equipment, laboratory processes or sample handling.

ECDC's laboratory and surveillance materials recognize multiple testing approaches within respiratory-virus monitoring and laboratory characterization.

Therefore, antigen and molecular tests should not be presented as interchangeable technologies.

The appropriate method depends on the intended use, required sensitivity, testing environment, turnaround time and applicable regulatory or clinical requirements.

Why Multiplex Respiratory Testing Matters in Europe

Europe's respiratory-virus situation is not defined by one pathogen.

ECDC's European Respiratory Virus Surveillance Summary (ERVISS) integrates information on influenza, RSV and SARS-CoV-2 across the EU/EEA and WHO European Region. The agency's 2026 surveillance guidance also emphasizes integrated respiratory-virus surveillance as a way to understand changing patterns of respiratory illness and support public-health action.

ECDC has additionally noted that other pathogens, including adenoviruses, may co-circulate with these viruses.

For diagnostic companies, this creates a strong rationale for considering multiplex respiratory testing rather than designing a portfolio around only one respiratory pathogen.

Who Can Benefit From a 5-in-1 Respiratory Antigen Test?

Pharmacies

A multi-target panel may provide a broader respiratory-testing option within a decentralized setting, where permitted by local regulations.

Clinics

Clinics may benefit from a compact respiratory-testing solution when several viral causes have overlapping presentations.

IVD Distributors

Distributors can offer a differentiated respiratory product covering five pathogen targets rather than marketing only single-pathogen assays.

Retail and Self-Testing Channels

Where self-testing is authorized, a five-target respiratory test can provide broader testing coverage within one product.

Healthcare and Diagnostic Companies

Organizations expanding their respiratory-test portfolio may consider multiplex products as part of a broader rapid-testing strategy.

The suitability of the product for a particular market depends on local regulatory authorization, intended use and market requirements.

BioTeke 5-in-1 Respiratory Antigen Test: Product Overview

Product specifications above are based on BioTeke's current product portfolio.

BioTeke currently presents the five-target test as part of its broader respiratory rapid-test portfolio, alongside 3-in-1, 4-in-1, 6-in-1, 7-in-1, 8-in-1 and 10-in-1.

What Does the BioTeke 5-in-1 Test Detect?

The panel detects antigens associated with five respiratory pathogens:

SARS-CoV-2

The virus responsible for COVID-19.

Influenza A

A major influenza virus type associated with seasonal influenza.

Influenza B

Another major influenza virus type that can cause influenza-like illness.

RSV

A respiratory virus included in ECDC's core European respiratory-virus surveillance programme.

Adenovirus

A group of viruses that can cause respiratory illness among other clinical syndromes.

The five-target configuration is designed to address a practical problem:

different respiratory pathogens can produce similar symptoms.

What Are the Limitations of a Rapid Antigen Test?

A negative rapid antigen result does not automatically exclude infection.

Performance can be influenced by factors such as:

• timing of testing

• specimen collection quality

• pathogen level in the specimen

• assay characteristics

• stage of infection

The performance of an antigen assay should therefore be evaluated using the specific product's technical documentation and intended use rather than generalized assumptions about all rapid tests.

For BioTeke's product, users should follow the applicable instructions for use and local requirements.

A rapid antigen test is a diagnostic testing tool; it should not be described as universally replacing molecular testing or clinical assessment.

Frequently Asked Questions

Can COVID-19, influenza and RSV cause similar symptoms?

Yes. Respiratory infections can have overlapping symptoms, including fever, cough, congestion and fatigue. ECDC monitors influenza, SARS-CoV-2 and RSV together within its integrated respiratory-virus surveillance approach because these pathogens contribute to the broader respiratory disease picture in Europe.

Can one test detect COVID-19, flu, RSV and adenovirus?

Yes. A multiplex assay can be designed to detect multiple pathogen targets from one respiratory specimen. The exact targets depend on the individual product.

What does the BioTeke 5-in-1 test detect?

It detects SARS-CoV-2, Influenza A, Influenza B, RSV and Adenovirus antigens from an anterior nasal swab specimen.

How long does the BioTeke 5-in-1 test take?

BioTeke's current product documentation states a 15–20 minute time to result.

Is the BioTeke 5-in-1 test a PCR test?

No. It is a multiplex antigen test using lateral-flow immunoassay technology.

Does a negative antigen result completely rule out infection?

No. Antigen tests have different analytical characteristics from molecular tests, and a negative result should be interpreted according to the product instructions and relevant clinical or regulatory guidance.

Who should consider a 5-in-1 respiratory antigen test?

Potential commercial users include pharmacies, clinics, diagnostic distributors, retailers and healthcare businesses, subject to the product's authorized intended use and applicable local regulations.

Conclusion: Five Respiratory Pathogens in One Testing Panel

COVID-19, influenza A, influenza B, RSV and adenovirus can produce overlapping respiratory symptoms. At the population level, ECDC's European surveillance framework reflects the importance of monitoring multiple respiratory pathogens together rather than focusing on one virus in isolation.

For decentralized respiratory testing, a multiplex antigen approach can provide broader pathogen coverage within one testing workflow.

The BioTeke 5-in-1 Multiple Respiratory Multipathogen Antigen Test Kit combines detection of:

SARS-CoV-2 + Influenza A + Influenza B + RSV + Adenovirus

using an anterior nasal swab and a lateral-flow immunoassay format, with a stated 15–20 minute time to result. BioTeke currently lists the product as an EU IVDR CE-marked self-test.

For distributors, pharmacies, diagnostic companies and healthcare partners, the five-target configuration offers a straightforward product proposition:

One test panel. Five respiratory pathogen targets. Rapid results.

BioTeke provides respiratory rapid-testing solutions for international healthcare and IVD markets. For information about the 5-in-1 test, technical documentation, regulatory documentation, packaging requirements or distribution opportunities, contact the BioTeke team.