Covid-19 reminded us of the threat of respiratory viruses. It is not the first pandemic to be caused by a respiratory virus and it is not likely to be the last. Influenza viruses are thought to have the potential to cause pandemics in the future.
According to the World Health Organization, 2.9 lakh to 6.5 lakh deaths occur during every flu season. As such, strategies preventing and treating influenza virus infections have become a major area of research.
There are four influenza viruses—A, B, C and D. Only A, B and C infect humans. C infections in humans are infrequent and mild. A and B infections can be severe, making them a public health problem.
Influenza viruses have a single-stranded segmented RNA genome. Influenza A and B have eight genes, each encoding for a different protein essential for the virus’s ability to infect and reproduce in humans. Out of these eight proteins, hemagglutinin (HA) and neuraminidase (NA) are on the surface of the virus.
HA is responsible for entry of the virus into our respiratory system. After replication, the new viral particles are released from the infected cell with the help of NA. Our immune system clears the infection by making antibodies. However, these antibodies are specific to the HA or NA and will either provide only partial protection or no protection against an influenza virus with different HA or NA.
Influenza A viruses cause both pandemics and seasonal influenza virus epidemics. Influenza A viruses are categorised into subtypes based on what HA and NA they have. There are 18 distinct HAs and 11 NAs found in nature, and, theoretically, viruses with any combinations of these are possible. For example, Influenza A H1N1 has type 1 HA and type 1 NA.
This story is from the December 06, 2020 edition of THE WEEK.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the December 06, 2020 edition of THE WEEK.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 8,500+ magazines and newspapers.
Already a subscriber? Sign In
There Is A Wind Blowing Against The BJP, And It Will Only Pick Up Speed
Interview - Akhilesh Yadav, Former Chief Minister, Uttar Pradesh
Between hospital and home
Transitional care centres can add a lot to India's health care system
EFFORT VS EFFECT
The government's attempts to ensure quality drugs is evident, but how well new policies can be monitored on the ground remains to be seen
A way to let go of fear
Accepting the use of adult diapers is a journey with various stages-denial, concealment, rejection and reluctance
Mandeeps & a miracle
Two strangers, one deadly disease and an act of kindness. How Mandeep Mann saved Mandeep Singh, an acute leukaemia patient, by donating his stem cells
The A, B, C of cosmetic surgery
Between eight to 10 lakh cosmetic surgeries happen in India every year. Who is an ideal candidate, and what are the risks and results you can expect?
Vaccines and meningitis
In sub-Saharan Africa, from Senegal in the west to Ethiopia in the east, and encompassing the northern part of Nigeria, there exists a region known as the African Meningitis Belt (AMB).
Celebrating diversity and inclusivity
As Indians battle it out in our nation's 18th general election, it is again time for voters to reflect on the \"Idea of India\"-or rather, on two duelling ideas of India that are now before us and between which the nation must choose at the ballot box.
Defendant: an Hermès handbag
When Hermès was hit with a class-action lawsuit last month for \"antitrust\" activities, it didn't see it coming. Most of the luxury world has all eyes on this suit, filed by two interested consumers who claim they were denied a purchase, and whether it would go to trial.
A legacy, bound
Amal Allana's biography of her father, Ebrahim Alkazi, is as much personal as it is historical