E-Paper
D-G ICMR’s ‘influenza virus from same family as Sars-Cov-2’ comment incorrect
Flu-like symptoms can be caused by several viruses, including the influenza virus, rhinovirus, and even some coronaviruses other than Sars-CoV-2, which causes Covid-19. However, the influenza viruses and coronaviruses belong to two different families
Dr Balram Bhargava, director-general (D-G) of Indian Council of Medical Research (ICMR), has said that in theory, influenza vaccines could work against coronavirus disease (Covid-19) as they belong to the same family, but in practice the two viruses do not have any similarities.
“It is scientifically plausible that it may help because the virus belongs to the same family. However, there is no data or evidence to show that influenza vaccine will help. We know that in influenza vaccine the strain changes every year. It is highly unlikely that the vaccine will benefit in the treatment Covid-19 patients,” said Dr Bhargava.
Influenza viruses are of four types: A, B, C and D. Human influenza A and B viruses cause seasonal diseases.
According to the US Centre for Disease Control (CDC), influenza A viruses are known to cause flu pandemics. Usually, Influenza type C infections cause mild illness and are not known to cause human flu epidemics. Influenza D viruses primarily affect cattle and are not known to cause illness among humans.
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“Flu-like symptoms can be caused by several viruses, including the influenza virus, rhinovirus, and even some coronaviruses other than Sars-CoV-2, which causes Covid-19. However, the influenza viruses and coronaviruses belong to two different families. So far, there is no evidence that the flu shot might help against Covid-19. But, I have been receiving a lot of requests from the public because of growing fear and panic about the Covid-19 pandemic,” said Dr GC Khilnani, a former head of the department of pulmonology at the All India Institute of Medical Sciences (AIIMS) in New Delhi.
Influenza A viruses are divided into subtypes based on two proteins on the surface of the virus: hemagglutinin (H) and neuraminidase (N).
There are 18 different hemagglutinin subtypes and 11 different neuraminidase subtypes (H1 through H18 and N1 through N11, respectively).
Current subtypes of influenza A viruses that routinely circulate in humans include A(H1N1) and A(H3N2).
Influenza B viruses are not divided into subtypes, but instead are further classified into two lineages: B/Yamagata and B/Victoria.
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“One influenza A (H1N1), one influenza A (H3N2), and one or two influenza B viruses (depending on the vaccine) are included in each season’s influenza vaccines… Seasonal flu vaccines do not protect against influenza C or D viruses. Flu vaccines will not protect against infection and illness caused by other viruses that also can cause influenza-like symptoms,” said CDC.
Coronaviruses (CoVs) are members of the family Coronaviridae, which envelop viruses that possess extraordinarily large single-stranded RNA (ribonucleic acid) genomes.
According to a paper published in the International journal of biological sciences, titled, Sars-CoV-2, An Emerging Coronavirus that Causes a Global Threat, “Currently, at least seven coronavirus species are known to cause diseases in humans. The viruses of 229E, OC43, NL63 and HKU1 only cause common cold symptoms, which are mild. Severe illness can be caused by the remaining three viruses, namely Sars-CoV, which resulted in the outbreak of Sars in 2002 and 2003 3,4; the coronaviruses that are responsible the Middle East respiratory syndrome (Mers-CoV), which emerged in 2012 and remains in the circulation in camels 7; and Sars-CoV-2, the viruses emerged in December 2019 in Wuhan in central China... “
