A 5-Minute History of the 2009 H1N1 Pandemic
Short on time?
We consolidate every article and add some fun visuals for our email subscribers. Click below to get our weekly articles delivered to your inbox every week!
TOPIC CONTEXT
Most weeks our team consolidates data from the left, right, and center to help you get answers to pivotal policy questions. In light of the COVID-19 outbreak - we are breaking out of our typical format to create a data hub for the latest updates on COVID-19.
KEY SOURCES
U.S. Center for Disease Control
World Health Organization
KEY THEMES
Health
Politics
We are breaking out of our traditional article format to deliver the data you need to contextualize the COVID-19 outbreak, which has impacted communities across the world.
Today, we're giving you the research behind the 2009 H1N1 Pandemic.
A word of caution:
It is tempting to compare previous pandemics with the current COVID-19 outbreak. However, that is not the intention of this article for several reasons including:
A word of caution: It is tempting to compare previous pandemics with the current COVID-19 outbreak. However, that is not the intention of this article for several reasons including:
H1N1 and COVID-19 are different: If you attempt to compare COVID-19 to the H1N1 pandemic, you will be comparing a different viruses with different epidemiological profiles (i.e. different rate of spread and mortality)
Our understanding of COVID-19 is evolving: Accurate information on COVID-19 cases and mortality rates are largely dependent on availability of testing, testing criteria, etc. Long story short, we're still learning about what we're dealing with here, and these viruses are always changing.
With that said, let's dive in...
The (H1N1)pdm09 virus strain was very different from other H1N1 viruses that were circulating at the time of the pandemic. CDC
Few young people had any existing immunity to the (H1N1)pdm09 virus, but nearly one-third of people over 60 years old had antibodies against this virus, likely from exposure to an older H1N1 virus earlier in their lives. CDC
In April 2009, the first patient was detected in California and 48 hours later the second case was identified over 130 miles away with no traceable connection between the patients. CDC
There was no vaccine to protect against influenza infection and no antibiotics to treat secondary bacterial infections.
On June 11th, 2009, the World Health Organization (WHO) declared the start of the first flu pandemic in 40 years. (Read more about the 1968 H3N2 Pandemic)
By mid-June all 50 states, the District of Colombia, Puerto Rico and the U.S. Virgin Islands had reported cases of 2009 H1N1 infection. CDC
The influenza peaked during May and June 2009 in the United States (U.S.), a few months after it's first detection. However, there was a second, smaller wave in fall of 2009 and the virus persisted at lower levels for several months in the Spring of 2010. CDC
One week after the first cases in the U.S., the CDC had reported cases to the WHO and activated their Emergency Operations Center to begin strengthening the nation's ability to detect and respond to public health threats. CDC
Between April 2009 and April 2010, CDC held 60 related media events – 39 press briefings and 22 telebriefings – reaching more than 35,000 participants. CDC
In May 2009, tests to detect 2009 H1N1 began to ship domestically and globally.
There were some disruptions to schools. In May 2009, the CDC recommended a 14 day dismissal in affected schools and childcare facilities with laboratory-confirmed cases of influenza A H1N1 virus. Peak school dismissal was in early May when 980 schools were dismissed.
There was no vaccine to protect against influenza infection and no antibiotics to treat secondary bacterial infections.
In September 2009, four influenza vaccine manufacturers received approval from the Food and Drug Administration for use of influenza A (H1N1) 2009 influenza vaccines in the prevention of influenza. CDC MMWR
While a monovalent (H1N1)pdm09 vaccine was produced, it was not available in large quantities until late November—after the peak of illness during which the second wave had come and gone in the United States. CDC MMWR
In August of 2009 WHO announced the end of H1N1 global influenza pandemic, roughly four months after the strain was detected. CDC
In the aftermath of the H1N1 pandemic, there is new, more detailed guidance on the use of non-pharmaceutical interventions to slow the spread of flu during a pandemic.
There is more capacity to make vaccines, and new vaccine technologies have been introduced (e.g., cell-grown and recombinant flu vaccines).
Progress in synthetic biology means that vaccine viruses can now be created in the lab using genetic sequencing data. CDC
CDC uses this technology to rapidly generate vaccine viruses against newly emerging avian and swine flu viruses that periodically cause illness in humans.
Globally, 80 percent of (H1N1)pdm09 virus-related deaths were estimated to have occurred in people younger than 65 years of age.
Usually, people 65 years and older represent 70 percent to 90 percent of seasonal influenza victims. CDC
From April 12, 2009 to April 10, 2010, CDC estimated there were 60.8 million cases, 274,304 hospitalizations, and 12,469 deaths in the U.S. due to the (H1N1)pdm09 virus. CDC
CDC estimated that 151,700 to 575,400 people worldwide died from (H1N1)pdm09 virus infection during the first year the virus circulated. CDC
When looking at the risk of a disease, terms like prevalence (measure of disease that allows us to determine a person's likelihood of having a disease), morbidity (another term for illness and is an important indicator for incidence of disease) and mortality (death from the disease) are important to understand before interpreting what you're reading. NY DOH
Influenza virus occurs annually, but changes in the virus makes it difficult to treat. This change can occur in 2 ways: antigenic drift and antigenic shift . CDC
Drift - these are very small changes in the genetic material.
Shift - these are very large and abrupt changes in the genetic material often due to a viral leap from one species to another (ex: animal to human). This is what occurred in both COVID19 and H1N1-09.
Swine flu has been around and is still around. It's the drifts and more often shifts that create problems for public health. CDC