Adenovirus
A large family of viruses that can cause respiratory illness, pink eye, or gastroenteritis.
What causes Adenovirus?
Adenovirus illness is caused by infection with one of many human adenoviruses. Depending on the type, the virus can spread through close contact, respiratory droplets, contaminated hands or surfaces, or contact with infected stool.
Symptoms and what to notice
Fever, sore throat, cough, runny nose, pink eye, or diarrhea and vomiting, depending on the virus type.
How long can it last?
Often several days to about two weeks; severe illness can last longer.
How serious is Adenovirus?
Usually mild, but pneumonia and other severe complications can occur, especially in people with weakened immune systems.
Treatment and management
Usually rest, fluids, and symptom care. Severe cases need medical assessment; there is no routine adenovirus-specific antiviral treatment.
Vaccine name, eligibility, doses, and cost
Product: Adenovirus Type 4 and Type 7 Vaccine, Live, Oral (no trade name). It is a one-time oral dose of two tablets for eligible U.S. military personnel ages 17–50 and is not available to the general public.
Approximate U.S. cost: The vaccine is not available to the U.S. general public, so there is no meaningful consumer retail price. Eligible military personnel receive it through the Department of Defense.
Official U.S. guidance
Adenovirus Disease: History, Symptoms, Transmission, Treatment, Prevention, and Vaccine Information
Adenovirus disease refers to illnesses caused by a large group of viruses known as human adenoviruses, or HAdVs. These viruses are extremely common and can infect people of almost any age. Most infections are mild and may look like an ordinary cold, sore throat, stomach infection, or pink eye. However, adenoviruses are capable of causing pneumonia, severe eye infections, gastrointestinal disease, bladder inflammation, and, in uncommon cases, serious neurological or widespread infection.
Unlike viruses that primarily attack one organ system, adenoviruses can infect several parts of the body. The respiratory tract, eyes, gastrointestinal tract, urinary tract, and lymphoid tissues can all be affected. This wide tissue range helps explain why two people infected with different adenovirus types can experience very different illnesses.
Adenovirus infections occur throughout the year rather than following one strict seasonal pattern. Most people recover without specific medical treatment, but infants, people with weakened immune systems, and people with certain heart or lung conditions can develop more serious disease.
Important: This article is for general education and is not a substitute for diagnosis or treatment from a qualified healthcare professional.
What Is an Adenovirus?
Adenoviruses belong to the Adenoviridae family. Human adenoviruses are non-enveloped viruses containing linear, double-stranded DNA.
Being non-enveloped is important from an infection-control perspective. Many viruses have a fragile fatty outer envelope that can be relatively easily disrupted. Adenoviruses do not have this envelope and can therefore remain comparatively stable in the environment and can resist some commonly used disinfectants.
The virus has an outer protein shell called a capsid. Important structural proteins include hexon, penton, and fiber proteins. The fiber structures help the virus attach to receptors on human cells, allowing the virus to enter the cell and begin infection.
Human adenoviruses are currently classified into seven species, A through G, with more than 100 genotypes recognized as genomic sequencing has expanded scientists' understanding of the group. Modern classification increasingly relies on genomic characteristics rather than the older serotype-only system.
Adenovirus Quick Facts
| Feature | Information |
|---|---|
| Virus family | Adenoviridae |
| Genetic material | Double-stranded DNA |
| Viral envelope | None |
| Human adenovirus species | A through G |
| Main illnesses | Respiratory infection, conjunctivitis, gastroenteritis |
| Other possible illnesses | Pneumonia, cystitis, hepatitis, neurological disease |
| Common transmission | Respiratory secretions, direct contact, contaminated surfaces, fecal-oral transmission |
| Water transmission | Possible, especially inadequately chlorinated pools |
| Typical respiratory incubation | Approximately 2 to 14 days |
| Typical enteric incubation | Approximately 3 to 10 days |
| Specific routine antiviral treatment | None FDA-approved |
| Civilian vaccine in the U.S. | No |
| U.S. military vaccine | Live oral vaccine against types 4 and 7 |
| Occurrence | Year-round |
The History of Adenovirus Disease
The history of adenovirus is closely connected with the development of modern virology and tissue-culture techniques.
1953: The First Discovery
The story began in 1953, when Wallace P. Rowe and colleagues were studying tissue obtained from human adenoids.
Researchers noticed that cells from surgically removed adenoids sometimes began degenerating spontaneously after they had been maintained in tissue culture. Further investigation showed that an infectious agent was responsible.
Rowe and colleagues published their discovery in December 1953 in a paper titled Isolation of a Cytopathogenic Agent from Human Adenoids Undergoing Spontaneous Degeneration in Tissue Culture.
The organism was initially described as an adenoid degeneration agent.
This discovery also helped reveal something important about adenovirus biology: these viruses can persist in lymphoid tissues such as the adenoids and tonsils.
1954: Adenoviruses Become Recognized as Respiratory Pathogens
Within a short period, researchers connected these newly discovered viruses with respiratory illnesses, pharyngitis, and conjunctivitis.
A major 1954 publication described what researchers called adenoidal-pharyngeal-conjunctival agents, helping establish this group of viruses as causes of human respiratory disease.
Different research teams initially used several names, including:
- Adenoid degenerative viruses
- Adenoidal-pharyngeal-conjunctival viruses
- Respiratory illness viruses
- Acute respiratory disease viruses
As evidence accumulated, scientists recognized that these apparently different agents belonged to the same major viral group.
1956: The Name "Adenovirus" Is Adopted
On May 25, 1956, researchers studying these viruses agreed to use the name adenovirus.
The proposed group name was published in Science in July 1956. The name refers to the adenoid tissue from which members of the virus group had originally been isolated.
Military Outbreaks Reveal the Importance of Adenovirus
Adenovirus soon became particularly important in military medicine.
Military recruits frequently live, sleep, eat, and train in close contact. These conditions allow respiratory viruses to spread efficiently.
During the 1950s and 1960s, adenovirus types 4 and 7 were major causes of acute respiratory disease among U.S. military trainees. Outbreaks sometimes resulted in large numbers of recruits becoming ill or requiring hospitalization.
Research into these outbreaks eventually helped drive the development of adenovirus vaccines.
1971: Routine Military Vaccination Begins
The U.S. military began routine use of live oral vaccines against adenovirus types 4 and 7 in 1971.
The vaccination program dramatically reduced adenovirus-associated acute respiratory disease among military recruits.
1990s: Vaccine Production Ends
The sole manufacturer eventually stopped vaccine production. Supplies became increasingly limited during the 1990s and were exhausted by 1999.
After routine vaccination disappeared, adenovirus respiratory disease returned to military training centers, demonstrating how effectively the vaccine had been suppressing types 4 and 7 disease.
2011: Adenovirus Vaccination Returns
A replacement adenovirus type 4 and type 7 vaccine received FDA approval in March 2011.
Routine use among U.S. military recruits resumed later that year. Surveillance subsequently documented a major decrease in adenovirus-associated febrile respiratory illness.
The vaccine remains a specialized military vaccine rather than a routine vaccine for civilians.
What Types of Adenovirus Cause Disease?
Different adenovirus types tend to have different tissue preferences, although these associations are not absolute.
Respiratory Adenovirus
Types frequently associated with acute respiratory disease include:
- Type 1
- Type 2
- Type 3
- Type 4
- Type 7
- Type 14
Types 4, 7, and 14 have been associated with outbreaks in crowded or congregate environments. Types 4 and 7 have also been associated with particularly severe outcomes in some circumstances.
Eye Infections
Adenoviruses can cause several forms of conjunctivitis.
Types associated with epidemic keratoconjunctivitis, a highly contagious infection involving the conjunctiva and sometimes the cornea, include:
- Type 8
- Type 19
- Type 37
- Type 53
- Type 54
Epidemic keratoconjunctivitis can be considerably more serious than ordinary mild pink eye because the cornea may become involved.
Gastrointestinal Adenovirus
Types 40 and 41 are known as important enteric adenoviruses and are associated particularly with gastroenteritis in children.
Symptoms can include diarrhea, vomiting, nausea, abdominal discomfort, and fever.
How Does Adenovirus Infect the Body?
Infection begins when adenovirus reaches susceptible cells, usually within a mucosal surface such as the:
- Nose
- Throat
- Airways
- Eyes
- Gastrointestinal tract
Viral fiber proteins interact with receptors on the surface of host cells. The virus enters the cell, releases its DNA, and uses the cellular environment to replicate.
New virus particles are produced and released, allowing infection to spread to neighboring cells.
The immune system usually controls the infection. However, adenovirus has another important biological characteristic: it can sometimes persist in the body.
Adenoviruses have been found to remain in lymphoid tissues such as the tonsils and adenoids without causing obvious symptoms. Persistent or latent virus becomes particularly important in people with severe immune suppression, in whom reactivation can occasionally contribute to serious disease.
How Does Adenovirus Spread?
Adenovirus can spread in several ways.
Respiratory Secretions
An infected person may release virus-containing respiratory particles when coughing or sneezing.
Close contact increases transmission risk.
Direct Personal Contact
Transmission can occur through close contact such as touching hands contaminated with respiratory or eye secretions.
Contaminated Objects and Surfaces
A person may touch an object contaminated with adenovirus and then touch the:
- Eyes
- Nose
- Mouth
The relative environmental stability of adenovirus makes contaminated surfaces particularly relevant in outbreak settings.
Fecal-Oral Transmission
Some adenoviruses can be transmitted through infected stool.
This route is especially important during:
- Diaper changing
- Inadequate handwashing
- Childcare activities
- Gastrointestinal outbreaks
Swimming Pools and Water
Adenovirus can occasionally spread through contaminated water.
Poorly chlorinated swimming pools have been associated with outbreaks, particularly illnesses involving conjunctivitis. Maintaining appropriate chlorine levels helps reduce this risk.
What Is the Incubation Period?
The incubation period is the time between exposure to the virus and development of symptoms.
It varies depending on the adenovirus type and the disease produced.
For many respiratory adenovirus infections, symptoms may appear approximately 2 to 14 days after exposure. Gastrointestinal adenovirus infections may have an incubation period of approximately 3 to 10 days.
How Long Is a Person Contagious?
There is no simple fixed contagious period that applies to every adenovirus infection.
People are particularly capable of spreading adenovirus while they are actively ill, but viral shedding can continue after symptoms improve.
CDC notes that some infected people, especially those with weakened immune systems, may continue shedding adenovirus for weeks or longer, even when symptoms are no longer present.
This prolonged shedding partly explains why infection-control measures remain important after apparent recovery in high-risk environments.
What Are the Symptoms of Adenovirus Disease?
Symptoms depend heavily on which part of the body is infected.
Respiratory Symptoms
Respiratory adenovirus disease may cause:
- Fever
- Runny or stuffy nose
- Sore throat
- Cough
- Headache
- Fatigue
- Swollen lymph nodes
- Bronchitis
Some infections resemble influenza or other common viral respiratory illnesses.
Pneumonia
Adenovirus can infect the lungs and cause pneumonia.
Possible symptoms include:
- Fever
- Persistent cough
- Rapid breathing
- Shortness of breath
- Chest discomfort
- Low oxygen levels in severe disease
Severe adenovirus pneumonia is uncommon in healthy people but can occur.
Conjunctivitis
Adenovirus is a common viral cause of pink eye.
Symptoms may include:
- Redness
- Irritation
- Watery eyes
- Tearing
- Swollen eyelids
- Gritty or foreign-body sensation
Some adenoviruses cause epidemic keratoconjunctivitis, in which the cornea can also become inflamed.
Eye pain, sensitivity to light, or reduced vision should receive prompt medical evaluation.
Pharyngoconjunctival Fever
A characteristic adenovirus syndrome called pharyngoconjunctival fever combines:
- Fever
- Sore throat
- Conjunctivitis
It has sometimes been associated with swimming-related outbreaks.
Gastroenteritis
Enteric adenoviruses can cause:
- Watery diarrhea
- Nausea
- Vomiting
- Abdominal pain
- Fever
Young children may be particularly vulnerable to dehydration during gastrointestinal illness.
Bladder Disease
Adenovirus can occasionally cause hemorrhagic cystitis, meaning inflammation of the bladder that can be accompanied by blood in the urine.
Symptoms can include:
- Painful urination
- Frequent urination
- Urinary urgency
- Blood in the urine
- Lower abdominal discomfort
Neurological Disease
Neurological complications are uncommon but have been documented.
Possible manifestations include inflammation affecting the brain or central nervous system.
CDC lists neurologic disease as a less common manifestation of adenovirus infection.
Who Is Most at Risk of Severe Adenovirus Disease?
Anyone can become infected, but certain groups have a higher risk of complications.
Young Children
Children experience many adenovirus infections because they have not yet developed immunity against multiple adenovirus types.
People With Weakened Immune Systems
Severe disease is particularly important in people whose immune systems are impaired by conditions or treatments such as:
- Organ transplantation
- Stem cell transplantation
- Cancer treatment
- Certain immune-suppressing medications
- Serious immune deficiencies
In these patients, adenovirus can sometimes spread beyond the original site of infection and produce disseminated disease.
People With Heart or Lung Disease
CDC identifies people with existing respiratory or cardiac disease as being at increased risk of developing severe adenovirus illness.
People Living in Congregate Settings
Transmission can increase wherever large numbers of people spend substantial time together, including:
- Military training centers
- Dormitories
- Schools
- Childcare facilities
- Residential institutions
What Complications Can Adenovirus Cause?
Most infections resolve without lasting consequences.
Possible complications, however, include:
- Severe pneumonia
- Respiratory failure
- Dehydration
- Severe keratoconjunctivitis
- Corneal complications
- Hemorrhagic cystitis
- Hepatitis
- Meningoencephalitis
- Disseminated adenovirus infection
The risk of severe or disseminated infection is much higher in significantly immunocompromised patients.
How Is Adenovirus Diagnosed?
Many uncomplicated cases do not require laboratory confirmation because symptoms resemble other self-limited viral infections.
Testing becomes more useful when:
- Illness is severe
- A patient is hospitalized
- The patient is immunocompromised
- An outbreak is suspected
- Identifying the pathogen could influence clinical or infection-control decisions
PCR Testing
Polymerase chain reaction, or PCR, is one of the most commonly available methods for detecting adenovirus.
Many hospitals use multiplex respiratory or gastrointestinal PCR panels capable of simultaneously testing for adenovirus and several other pathogens.
Antigen Testing
Certain laboratories can identify adenovirus antigens.
Viral Culture
Adenovirus can also be grown in cell culture, although culture is less commonly used for routine diagnosis today.
Genomic Sequencing and Typing
Specialized laboratories can determine the adenovirus type using partial or complete genomic sequencing.
Typing is especially useful during outbreak investigations rather than routine uncomplicated infections.
CDC recommends choosing specimens according to the patient's clinical presentation and notes that molecular methods such as NAAT or PCR are central laboratory tools.
How Is Adenovirus Disease Treated?
For most people, treatment is supportive.
There is currently no FDA-approved antiviral medication specifically for routine adenovirus treatment.
Supportive care may include:
- Adequate fluids
- Rest
- Fever control
- Appropriate pain relief
- Monitoring for breathing problems
- Monitoring for dehydration
Antibiotics do not treat adenoviruses because antibiotics work against bacteria, not viruses.
A healthcare professional should determine whether symptoms might instead be caused by a bacterial infection that requires different treatment.
Severe Adenovirus Infection
Hospitalized or severely immunocompromised patients require a different level of management.
Care may involve:
- Oxygen therapy
- Intravenous fluids
- Respiratory support
- Management of organ complications
- Specialist infectious-disease consultation
Certain antiviral medications have been studied or used in selected severe cases, particularly among immunocompromised patients, but this is specialist treatment. It should not be interpreted as routine therapy for ordinary adenovirus infections.
CDC recommends infectious-disease consultation for hospitalized patients with severe adenovirus infection.
Is There an Adenovirus Vaccine?
Yes, but its availability is highly restricted.
Adenovirus Vaccine for the U.S. Military
The United States has a live oral vaccine against:
- Adenovirus type 4
- Adenovirus type 7
The vaccine is approved for eligible U.S. military populations aged 17 through 50 years.
A complete dose consists of two tablets taken orally:
- One type 4 tablet
- One type 7 tablet
The tablets must be swallowed whole rather than chewed or crushed.
Is There an Adenovirus Vaccine for the General Public?
No.
As of the current CDC guidance, there is no adenovirus vaccine routinely available to the general U.S. population.
The military vaccine is not approved for general civilian use.
Is There a Brand Name?
The FDA lists the product as Adenovirus Type 4 and Type 7 Vaccine, Live, Oral and does not list a conventional trade name.
Why Is the Vaccine Mainly Used by the Military?
Military recruits have historically faced unusually high adenovirus transmission because of:
- Close living quarters
- Group training
- Shared facilities
- Large numbers of susceptible young adults arriving at the same location
Types 4 and 7 caused major outbreaks in this population, making targeted vaccination particularly valuable.
How Can Adenovirus Infection Be Prevented?
Because most civilians do not have access to an adenovirus vaccine, prevention primarily depends on reducing transmission.
Wash Hands Properly
Wash hands regularly with soap and water, especially:
- After using the bathroom
- After changing diapers
- Before eating
- Before preparing food
- After caring for someone who is sick
Avoid Touching the Face
Avoid touching the eyes, nose, and mouth with unwashed hands.
Reduce Close Contact While Sick
People with respiratory symptoms should limit close contact with others when practical.
Do Not Share Personal Items
Avoid sharing objects that may contact the eyes, face, or respiratory secretions, such as:
- Towels
- Washcloths
- Eye cosmetics
- Eye drops
- Drinking containers
Clean Shared Surfaces
Good environmental cleaning is particularly important during outbreaks because adenoviruses can be relatively resistant in the environment.
Maintain Proper Swimming Pool Chlorination
Correct pool disinfection reduces the risk of water-associated adenovirus outbreaks. CDC specifically emphasizes maintaining adequate chlorine levels to help prevent adenoviral conjunctivitis outbreaks.
Adenovirus Outbreaks and Public Health Surveillance
Adenovirus differs from influenza and several other respiratory infections because it does not have one predictable annual season. Outbreaks can occur at any time of year.
In the United States, adenovirus infection is not a nationally notifiable disease, which means every diagnosed case does not have to be reported to CDC.
This makes the true number of infections difficult to determine.
CDC uses systems including the National Respiratory and Enteric Virus Surveillance System, or NREVSS, to monitor laboratory adenovirus activity.
The National Adenovirus Type Reporting System, or NATRS, collects information on typed adenovirus specimens and helps researchers understand which types are circulating.
CDC surveillance covering 2017 through 2023 found that adenovirus types 1, 2, 3, 4, 7, and 14 accounted for the large majority of typed specimens reported to NATRS during that period.
Because NATRS is a passive system involving a limited number of participating laboratories, these data should not be interpreted as representing every adenovirus infection in the United States.
Can You Get Adenovirus More Than Once?
Yes.
Adenovirus is not a single virus type. Numerous different human adenoviruses circulate.
Immunity following infection with one type does not necessarily provide complete protection against all other adenovirus types.
A person can therefore experience adenovirus infection more than once during life.
Is Adenovirus the Same as the Common Cold?
Not exactly.
Adenovirus can cause symptoms that look like a common cold, but many different viruses can produce cold-like illnesses.
Adenovirus is only one possible cause.
It can also cause illnesses that ordinary cold viruses usually do not cause, including:
- Gastroenteritis
- Epidemic keratoconjunctivitis
- Hemorrhagic cystitis
- Severe pneumonia in susceptible people
Adenovirus and Adenoviral Vectors Are Not the Same Thing
The word "adenovirus" is also encountered in discussions of vaccines, gene therapy, and biomedical research.
Scientists can modify adenoviruses so they act as vectors, meaning delivery vehicles that transport selected genetic material into cells.
These engineered adenoviral vectors are different from naturally acquired adenovirus disease. The ability of adenoviruses to efficiently enter human cells is one reason researchers have studied them extensively for biotechnology and medical applications.
When Should Someone Seek Medical Care?
Medical evaluation should be considered when adenovirus-like illness is severe, persistent, or occurs in a person at increased risk of complications.
Seek prompt medical attention for symptoms such as:
- Difficulty breathing
- Severe shortness of breath
- Bluish or grayish lips or skin
- Severe chest pain
- Signs of significant dehydration
- Inability to keep fluids down
- Very low urine output
- Unusual sleepiness or difficulty waking
- Confusion
- Seizures
- Blood in the urine
- Severe eye pain
- Sensitivity to light
- Reduced or changing vision
- Rapidly worsening illness
Parents and caregivers should seek medical advice promptly when an infant or young child appears seriously ill, has difficulty breathing, cannot maintain hydration, or becomes unusually sleepy or difficult to wake.
People with major immune suppression should contact their healthcare team earlier because adenovirus can behave differently in this population.
Frequently Asked Questions About Adenovirus
Is adenovirus dangerous?
Usually not. Most infections are mild and resolve without specific treatment. Severe disease can occur, particularly in infants, immunocompromised people, and people with underlying respiratory or cardiac disease.
Can adenovirus cause pneumonia?
Yes. Adenovirus can cause viral pneumonia and occasionally severe lower respiratory disease.
Can adenovirus cause diarrhea?
Yes. Adenovirus types 40 and 41 are particularly associated with gastroenteritis.
Can adenovirus cause pink eye?
Yes. Adenoviruses are important causes of viral conjunctivitis and epidemic keratoconjunctivitis.
Can adenovirus spread through swimming pools?
Yes, although this is less common than person-to-person transmission. Inadequately chlorinated pools can contribute to outbreaks.
Do antibiotics cure adenovirus?
No. Adenovirus is a virus, so antibiotics do not directly treat the infection.
Is there medicine that kills adenovirus?
There is no FDA-approved antiviral medication for routine treatment of adenovirus infection. Most cases are treated with supportive care.
Does everyone with adenovirus have symptoms?
No. Adenovirus infections can be asymptomatic. Detecting adenovirus does not always prove that adenovirus is responsible for every symptom a patient is experiencing.
Can someone spread adenovirus after recovering?
Yes. Viral shedding can continue after symptoms resolve and may last much longer in certain people, particularly those with impaired immune systems.
Is adenovirus seasonal?
Not strictly. Adenovirus disease and outbreaks can occur throughout the year.
Is an adenovirus vaccine available?
A live oral vaccine against types 4 and 7 is available for eligible U.S. military personnel. There is currently no adenovirus vaccine routinely available to the general public in the United States.
The Larger Significance of Adenovirus
Adenovirus occupies an unusual position in infectious-disease history.
It began as an unexpected laboratory finding in children's adenoid tissue in 1953. Within only a few years, scientists recognized that this was not a single obscure virus but a broad family of human pathogens capable of causing respiratory, ocular, gastrointestinal, urinary, and systemic disease.
Military outbreaks subsequently demonstrated the virus's ability to spread rapidly through crowded populations and helped drive the development of one of the more specialized vaccines used in modern medicine.
Today, advanced molecular testing and genomic sequencing continue to reveal additional adenovirus genotypes and provide a clearer picture of how these viruses evolve and circulate. More than seven decades after its discovery, adenovirus remains both a common cause of everyday illness and an important pathogen in outbreak investigations and immunocompromised patients.
For most healthy individuals, infection remains temporary and self-limited. The greatest clinical importance lies in recognizing the situations in which an apparently ordinary viral illness may become more serious, particularly severe respiratory disease, significant dehydration, eye involvement, or infection in a person with substantial immune suppression.
Information reviewed against CDC and FDA guidance available through September 2026.