However, in addition to the COVID-19 pandemic, we’ve also experienced another pandemic relatively recently: the 2009 H1N1 influenza pandemic.
You may be curious how these two pandemics compare with each other. Keep reading as we break down their similarities and differences below.
Before we go on to compare the two pandemics in more detail, here are some fast facts about each of them.
|2009 H1N1 Influenza||COVID-19|
|Year started – year ended||2009–2010||2020–present|
|Worldwide deaths||about 284,000 in the first 12 months||about 2,000,000 in the first 12 months|
|Virus||2009 H1N1 influenza virus||SARS-CoV-2 coronavirus|
|Transmission||respiratory droplets and aerosols, contact with contaminated surfaces, asymptomatic spread||respiratory droplets and aerosols, contact with contaminated surfaces, asymptomatic spread|
|Contagiousness||less contagious than COVID-19, contagious from 1 day before symptoms begin until 5 to 7 days after becoming sick||more contagious than 2009 H1N1 influenza, contagious from 2 days before symptoms begin until 10 days after testing positive|
|Symptoms||fever and chills, fatigue, cough, body aches and pains, headache, sore throat, runny or stuffy nose, digestive symptoms like diarrhea and vomiting||similar symptoms to 2009 H1N1 influenza, but also includes loss of smell and taste|
|Symptom onset||sudden after 1 to 4 days||gradual after 2 to 14 days|
|Age group most impacted||people younger than 30||adults over age 30|
|Illness severity||94–98 percent mild||80 percent mild, 20 percent severe or critical|
|Risk factors||being 65 years or older, being younger than 5 years old, being pregnant, having certain underlying health conditions||being 65 years or older, being pregnant, having certain underlying health conditions|
|Complications||pneumonia, worsening of underlying health conditions, secondary bacterial infections, respiratory failure, inflammation of tissues of the heart, brain, or muscles, injury to the kidneys or liver, acute respiratory distress syndrome (ARDS), sepsis||same complications as 2009 H1N1 influenza, but also includes: |
long-haul COVID-19, blood clots, multisystem inflammatory syndrome in children (MIS-C)
|Treatments||supportive care, FDA-approved antiviral medications like oseltamivir (Tamiflu)||supportive care, FDA-approved antiviral remdesivir (Veklury), various treatments under Emergency Use Authorization|
|Vaccines||several vaccines developed||several vaccines developed|
Let’s look at some of the similarities between the 2009 H1N1 influenza and COVID-19 pandemics.
Both 2009 H1N1 influenza and COVID-19 can be transmitted in similar ways. These include:
- Respiratory droplets and aerosols. These are tiny droplets that are made when a person who has the virus talks, sneezes, or coughs. If you inhale these droplets or aerosol particles, you can contract the virus.
- Contaminated objects. Respiratory droplets containing virus can land on things like countertops and doorknobs. You can contract the virus by touching these things and then touching your mouth, nose, or eyes.
It’s also possible for a person to pass both viruses when they don’t have any symptoms. This is called asymptomatic transmission.
Both 2009 H1N1 influenza and COVID-19 are respiratory infections that share many symptoms in common. These can include:
- fever and chills
- body aches and pains
- sore throat
- runny or stuffy nose
- digestive symptoms like diarrhea and vomiting
One symptom that’s unique to COVID-19 is loss of smell and taste.
The 2009 H1N1 influenza and COVID-19 can range from mild to severe. In both pandemics, certain groups were at an increased risk for severe illness.
The groups at risk for complications from 2009 H1N1 influenza and COVID-19 have significant overlap. They include:
- adults aged 65 and over
- pregnant people
- those with certain types of underlying health conditions
Underlying health conditions that can contribute to complications include:
- chronic lung diseases, such as asthma, chronic obstructive pulmonary disorder (COPD), and cystic fibrosis
- developmental disorders like Down syndrome
- heart disease, including heart failure or coronary artery disease
- kidney disease
- liver disease
- neurological conditions, such as stroke and dementia
- sickle cell disease
- weakened immune system due to cancer treatments, HIV/AIDS, or immunosuppressive drugs
Additional high risk groups for the 2009 H1N1 influenza
Some additional groups that were at a
- children under the age of 5
- people under the age of 19 who were receiving long-term aspirin therapy
Additional high risk groups for COVID-19
Additionally, people with the following underlying health conditions are at a
Both 2009 H1N1 influenza and COVID-19 can lead to similar complications, including:
- worsening of underlying health conditions
- secondary bacterial infections
- respiratory failure
- inflammation of tissues of the heart, brain, or muscles
- injury to the kidneys or liver
- acute respiratory distress syndrome (ARDS)
COVID-19 also has a few additional complications, including:
After the emergence of 2009 H1N1 influenza and COVID-19, efforts were quickly made to develop a vaccine.
Over the course of the 2009 H1N1 influenza pandemic,
According to the
- mRNA (Pfizer-BioNTech, Moderna)
- viral vectors (Johnson & Johnson, Oxford-AstraZeneca)
- protein subunits (Novavax)
Three vaccines are currently authorized by the FDA for emergency use in the United States. These include the vaccines produced by:
Now let’s explore the differences between the two pandemics.
The type of virus
The 2009 H1N1 pandemic was caused by an influenza virus. Influenza viruses are part of the viral family Orthomyxoviridae. Their genetic material consists of eight separate strands of RNA.
This specific influenza virus jumped to humans from pigs in 2009, hence its moniker “swine flu.” It actually contains RNA strands of human, swine, and avian origin. How does this happen?
Pigs can get several different types of influenza virus. When this happens, the RNA strands from the different viruses can mix together through a process called reassortment. This can create a unique influenza virus, such as the 2009 H1N1 virus.
COVID-19 is caused by a coronavirus from the viral family Coronaviridae. Its genetic material consists of a single strand of RNA. The specific virus that causes COVID-19 is called SARS-CoV-2.
The exact origin of SARS-CoV-2 is still unknown. A recently released report from the
COVID-19 has caused significantly more deaths worldwide. It’s estimated that about
As with 2009 H1N1 influenza, deaths due to COVID-19 will continue during and after the pandemic. At the time of writing, COVID-19 has caused almost 3,000,000 deaths worldwide. Over 500,000 deaths have occurred in the United States.
COVID-19 is more contagious than 2009 H1N1 influenza. This means that COVID-19 can spread more easily between individuals.
So, one person who’s developed COVID-19 may potentially transmit the virus to three other people. Meanwhile, a person that has 2009 H1N1 influenza may pass it to between one to two other people.
The period of contagiousness between the two viruses can also vary:
- Flu: A person who has
the flucan typically pass the virus from 1 day before symptoms start until 5 to 7 days after becoming ill.
COVID-19can be passed about 2 days before symptoms start. Whether or not symptoms are present, a person can pass the virus for up to 10 days after testing positive.
Flu, including the 2009 H1N1 flu, and COVID-19 differ when it comes to symptom onset:
- Flu: The incubation period for flu can range from
1 to 4 days. When symptoms occur, they often come on suddenly.
- COVID-19: COVID-19 has a longer incubation period, ranging from
2 to 14 days, although many people develop symptoms 5 daysafter contracting the virus. Symptoms typically appear more gradually.
Age group most impacted
The two pandemics also differed in the age groups that were most impacted:
- 2009 H1N1 influenza: People
under the age of 30were most impacted by the 2009 H1N1 influenza pandemic. It’s believed that this is due to pre-existing influenza immunity in older people.
- COVID-19: Adults aged 30 and over have been most impacted by the COVID-19 pandemic. Generally speaking, fewer and less severe cases have been observed in younger people.
It’s estimated that between
A higher percentage of people who develop COVID-19 have severe illness. The
The treatment for 2009 H1N1 influenza included supportive care and antiviral medications. Supportive care involves:
- getting enough rest
- drinking plenty of fluids
- using over-the-counter (OTC) medications like acetaminophen (Tylenol), ibuprofen (Advil, Motrin), and naproxen (Aleve) to ease symptoms like fever and pain
When COVID-19 first emerged, however, we didn’t know of any treatments that were effective against it. Over time, various therapies have either been approved by the FDA or authorized for emergency use.
Mild to moderate COVID-19 is often treated with supportive care. Additional treatments are also available to people who are hospitalized or at a high risk of serious illness. These can include:
- remdesivir (Veklury), the only FDA-approved antiviral treatment for COVID-19
- SARS-CoV-2-neutralizing antibodies
- dexamethasone, a type of steroid medication
- COVID-19 convalescent plasma
We’ve experienced two different pandemics in the 21st century: the 2009 H1N1 influenza pandemic and the COVID-19 pandemic. There are various similarities and differences between these two pandemics.
Although they’re caused by different viruses, both 2009 H1N1 influenza and COVID-19 are respiratory illnesses that are transmitted in the same way. There’s also a lot of overlap in symptoms, complications, and risk factors for serious illness.
However, COVID-19 is more likely to cause serious illness than 2009 H1N1 influenza and has led to more deaths worldwide. It’s also more contagious than 2009 H1N1 influenza.
While effective treatments weren’t known at the beginning of the COVID-19 pandemic, we now have several that are available. Additionally, as in the 2009 H1N1 influenza pandemic, vaccines have been rapidly developed for COVID-19.