The highly contagious COVID-19 – the disease caused by the deadly novel coronavirus – was declared a pandemic by the World Health Organization (WHO) on March 11. This was the first time a disease was declared a pandemic since the 2009 H1N1 swine flu.
The coronavirus pandemic displays symptoms akin to previous outbreaks such as the SARS and swine flu but is remarkably distinct from them in effect. Pointing out the primary difference between COVID-19 and other flu-related pandemics, WHO Director-General Tedros Adhanom Ghebreyesus says this is the first time a pandemic has been sparked by a coronavirus.
History of pandemics
The first recorded pandemic is believed to be flu-related too. It possibly broke out somewhere in Asia back in 1580.
The 1918 Spanish flu is considered the deadliest pandemic to date. It was an avian flu carried by the H1N1 virus, which killed 40-50 million people. However, those were difficult times -- the World War I was being fought, living conditions were tough and medical care was not still as advanced.
Frequently Asked Questions
A vaccine works by mimicking a natural infection. A vaccine not only induces immune response to protect people from any future COVID-19 infection, but also helps quickly build herd immunity to put an end to the pandemic. Herd immunity occurs when a sufficient percentage of a population becomes immune to a disease, making the spread of disease from person to person unlikely. The good news is that SARS-CoV-2 virus has been fairly stable, which increases the viability of a vaccine.
There are broadly four types of vaccine — one, a vaccine based on the whole virus (this could be either inactivated, or an attenuated [weakened] virus vaccine); two, a non-replicating viral vector vaccine that uses a benign virus as vector that carries the antigen of SARS-CoV; three, nucleic-acid vaccines that have genetic material like DNA and RNA of antigens like spike protein given to a person, helping human cells decode genetic material and produce the vaccine; and four, protein subunit vaccine wherein the recombinant proteins of SARS-COV-2 along with an adjuvant (booster) is given as a vaccine.
Vaccine development is a long, complex process. Unlike drugs that are given to people with a diseased, vaccines are given to healthy people and also vulnerable sections such as children, pregnant women and the elderly. So rigorous tests are compulsory. History says that the fastest time it took to develop a vaccine is five years, but it usually takes double or sometimes triple that time.
Later, in the late 1950s, another flu strain was detected in China’s Yunnan, which claimed more than one million lives. A few years from that, the Hong Kong flu pandemic killed somewhere between 500,000 to two million people.
Then came the 2009 H1N1 pandemic, which has so far killed about six million people.
The Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) were two coronavirus outbreaks that took place in the past 20 years. However, the novel coronavirus-induced COVID-19 has proved deadlier than both. SARS killed 916 people while 858 people died of MERS.
How is COVID-19 different from other major outbreaks?
The COVID-19 is caused by a coronavirus while the 1918 flu pandemic was caused by an influenza virus.
In the case of SARS, people became infectious at a stage when they got really very sick. But, in the case of COVID-19, people who do not display any symptom may also be carrying the deadly pathogen. Medics and researchers have also noted that several coronavirus cases would eventually go undocumented altogether because no symptom will be experienced or would be too mild. These would be the people who would become potential carriers exposing thousands of people to the virus, whom it may affect far more severely and even kill. This is why, despite having a low fatality rate, COVID-19 has killed more people than SARS or MERS – both of which had a far higher mortality rate.
As for the 2009 flu, the pandemic primarily affected children and youth while 80 percent of the deaths recorded were people aged below 65 years. But, in novel coronavirus infections, the highest percentage of deaths were among people aged above 65 years. Besides, the H1N1 virus was far less contagious than the novel coronavirus.More than 500,000 suspected cases of Zika virus were reported in 2015 and 2016, but only 18 people died of it. It was transmitted primarily through mosquitoes, unlike the coronavirus that spreads through respiratory fluids such as mucus or saliva.