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.
هذه القصة مأخوذة من طبعة December 06, 2020 من THE WEEK.
ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.
بالفعل مشترك ? تسجيل الدخول
هذه القصة مأخوذة من طبعة December 06, 2020 من THE WEEK.
ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.
بالفعل مشترك? تسجيل الدخول
What Will It Take To Clean Up Delhi Air?
IT IS ASKED, year after year, why Delhi’s air remains unbreathable despite several interventions to reduce pollution.
Trump and the crisis of liberalism
Although Donald Trump's election to a non-consecutive second term to the US presidency is not unprecedented—Grover Cleveland had done it in 1893—it is nevertheless a watershed moment.
Men eye the woman's purse
A couple of months ago, I chanced upon a young 20-something man at my gym walking out with a women’s sling bag.
When trees hold hands
A filmmaker explores the human-nature connect through the living root bridges
Ms Gee & Gen Z
The vibrant Anuja Chauhan and her daughter Nayantara on the generational gap in romance writing
Vikram Seth-a suitable man
Our golden boy of literature was the star attraction at the recent Shillong Literary Festival in mysterious Meghalaya.
Superman bites the dust
When my granddaughter Kim was about three, I often took her to play in a nearby park.
OLD MAN AND THE SEA
Meet G. Govinda Menon, the 102-year-old engineer who had a key role in surveying the Vizhinjam coast in the 1940s, assessing its potential for an international port
Managing volatility: smarter equity choices in uncertain markets
THE INDIAN STOCK MARKET has delivered a strong 11 per cent CAGR over the past decade, with positive returns for eight straight years.
Investing in actively managed low-volatility portfolios keeps risks at bay
AFTER A ROARING bull market over the past year, equity markets in the recent months have gone into a correction mode as FIIs go on a selling spree. Volatility has risen and investment returns are hurt.
