A recent discovery of an antibody that works on more than one strains of Influenza Virus Type A. This article Provides detailed information about the same.
Two research papers are in the news recently. Nature Medicine: A group of Researchers tested a universal flu vaccine on mice and ferret. Science: A team tested similar universal flu vaccine on monkeys. The vaccine contained an antigen that could target multiple strains of Type A Influenza, with a possibility of one time, ideally once-in-a-lifetime flu shot instead of present day scenario of annual flu shots. Both results came positive. Infectious Disease Experts quote this as a pivotal discovery.Background
Influenza virus is responsible for a highly infectious (and might I add, very annoying!) disease called Influenza, or flu. Who hasn't been a victim of of this sneezing, coughing situation with near-full body-ache, medium to high grade fever and a runny nose ? Living in an open window house or a centrally climate controlled apartment, all of us have our fair share of getting infected.
Shaped roughly spherical with about 80 to 120 nanometres, Influenza virus has three major types, conveniently known as A, B and C. This virus is highly variable in its structure, mutating continuously. and at times infects multiple species. Virus uses HA (Hemagglutinin) to attach to pulmonary cells, seen as pinkish heads in the image. This HA portion is different for different strains of virus.
Type A is the most volatile of all three major types:
- It exhibits the shortest time-span for mutation and hence quickest mutation rate of all three.
- Wild Birds are its primary natural hosts. It makes its way into human species through the domestic poultry, often resulting in pandemics.
- Recent pandemics include subtype H5N1 Bird Flu of 2004 and subtype H1N1 Swine Flu in 2009.
The Flu Vaccine
From CDC of USA to NCDC of India, almost all national bodies of disease control and prevention recommend taking a flushot developed exclusively for that particular year. This flushot or Influenza Vaccine that are presently available as trivalent or tetravalent.
Trivalent : It contains antigen for two subtypes of A (H1N1 and H3N2) + antigen for one subtype of B. A total of 3 kinds of antigens.
Tetravalent: It contains all of above with antigen for another subtype of B. A total of 4 kinds of antigens.
While this can effectively protect against only a few strains, it helps control the symptoms and spreading of flu for all strains to a certain degree.
A limitation of Flu Vaccine is that they have to be developed every year to adapt major known mutations of Influenza Virus.
Because of this limitation, every year a lot of recurring research and development costs are associated with flu shots along with its manufacturing costs. Taking annual flu shots is considered a cost effective treatment only for senior citizens and kids, at least till the 2015 version of Flu Vaccine.
Method of Delivery
Flu Vaccines can be administered in two popular ways as on today:
Traditional method of injecting it and a recently popularized method of spraying as a nasal mist (intranasal). While flushots can be injected to any recipient 6 months and above, intranasal sprays are useful only for the age group of 2 to 49 years, of course with a doctor's advice, and avoiding situations such as pregnancy.
Universal Vaccine of Influenza
Since 1938, the vaccines and its antigens are prepared by targeting the HA portion, the head of virus. This limits a single antigen to work on only one strain of virus.
The methodology adapted to create Universal Vaccine targets stem of virus instead of the ever-changing HA portion. Ideally, one shot of such vaccine will generate antibodies to fight flu virus for a life time, instead of present practice of taking a shot every year.
It will be a welcome solution all across the globe and perhaps just as much important as discoveries of Edward Jenner's smallpox vaccine and Alexander Fleming's penicillin. Hopefully, Human Trials will soon begin and last for at least a decade before such vaccines will be available.
Some experts have served a concern that the Influenza Virus might begin to mutate in its stems in response to the vaccine rendering the universal flu vaccine useless.
Flu Seasons and Virus Strains Across the Globe
Influenza attacks are seasonal across the globe, changing according to climate and demographics of country. World Health Organization monitors and documents Influenza activity through GISRS. Sample results are collected from GISRS servers. This shows how different strains are active at different times in Asia, Europe and Americas.
A Universal Flu Medicine, if available, will unify the flu vaccine instead of cocktailing antigens for multiple strains and taking annually during the flu seasons.
India
Active Months: February to April.
Predominant virus strain : A, Subtype H1N1 and H3
Use of Flu shots: Very Little
United Kingdom
Active Months: December to June.
Predominant virus strain : A - Dec to March, B - March to June
Use of Flu shots: Moderate to High
France
Active Months: January to March.
Predominant virus strain : A, often not subtyped, Subtype H1N1 and type B
Use of Flu shots: Moderate
Germany
Active Months: February to April.
Predominant virus strain : A, Subtype H3 and B, subtype Yamagata Linage
Use of Flu shots: Very Little
USA
Active Months: November to April.
Predominant virus strain : A, Subtype H3 and B
Use of Flu shots: High
Canada
Active Months: November to April.
Predominant virus strain : A, Subtype H3, B
Use of Flu shots: High
Oman
Active Months: November to April.
Predominant virus strain : A, Subtype H1N1, B
Use of Flu shots: Moderate to High
With the hope the universal flu vaccine turns from a promising research to shear reality putting an end to billions of sufferings in form of sneezing and coughing, I believe this article helps grasping the importance of this recent development.
Content of this blog is for health awareness purposes only and should not be construed as a medical prescription or advice. Be advised to always consult your physician or pharmacist regarding medical conditions, medications or medical procedures.
- Friday, September 04, 2015
- 0 Comments
