By Joseph Hazan,M.D., FACOG
More new facts are emerging in
the quest to conquer the flu virus.
Initially, the H1N1 virus appeared
in 1918
as it spawned the most dangerous
pandemic on record.
This strain of virus in its weakened
form returned every year for about
30 years until it reassorted its genetic
structure and appeared as the Asian flu
pandemic in 1957.
This reassortment was due to a patient
who was infected with both the H1N1 and
H2N2 avian virus came up with a new
immunological type of virus which resulted
from the reassortment of the genes of those
two viruses.
This was the initial emergence of the new
H2N2 virus.
This pandemic in 1957 was not as
widespread or severe as the one in
1918, “the Spanish influenza”.
Later, in 1968 the ” Hong Kong flu”
emerged when a patient who had the
seasonal H2N2 virus was also infected
with the H3 avian, “bird” flu.
This was not as severe as the 1918 flu either.
Subsequently, the H3N2 and H1N1
combinations have appeared
since the 70’s.
The yearly flu vaccines target those
two viruses and the influenza B virus.
However, the H5N1 avian, “bird” flu
started in 1997 and starting in
Hong Kong caused 433 human cases
with 262 fatalities.
The current H1N1″ so called
-swine flue- started in 1998 in the U.S.
It was first detected in pigs.
This virus has the genetic make up
of genes from the human, bird and swine
flu viruses.
Pigs can catch viral illness from
humans and birds.
This Spring this virus resurfaced in
Mexico and is
found to be highly transmissible and
virulent.
It spread from Mexico to California
and by June it became a pandemic.
It infects the young and pregnant
women appear more vulnerable.
The high mortality rate among the
young appears to be due to the strong
immune response the young people are
able to mount,resulting in
a “cytokine storm”
which could be an immune response
that devastates the host.
Finally, the long awaited H1N1
vaccine has now arrived and will
be available starting this week.
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