In a first, WHO recommends quadrivalent influenza vaccine

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Mains Paper 2: Governance | Issues relating to development and management of Social Sector/Services relating to Health, Education, Human Resources.

The following things are important from UPSC perspective:

Prelims Level: Influenza Strain Types,  H#N# Subtypes

Mains level: Read the attached story


News

Quadrivalent vaccine approved

  1. Sanofi Pasteur’s injectable influenza vaccine (FluQuadri) containing two A virus strains — H1N1 and H3N2 — and two B virus strains — Victoria and Yamagata — for active immunisation of adults of age 18 to 64 years was approved in May last year by the Drug Controller General of India (DCGI).
  2. The application for the paediatric indication is under review by the DCGI and final approval is expected by the end of this month.
  3. Sanofi’s quadrivalent influenza vaccine was licensed for use by the U.S. Food and Drug Administration (FDA) in 2013; it is licensed in 26 countries.

Why Quadrivalent vaccine?

  1. While a trivalent influenza vaccine contains both A subtype viruses, it has only one of the B subtype virus, the quadrivalent vaccine offers a greater breadth of protection as it includes both B subtype viruses.
  2. It is because of a greater breadth of protection that a few other companies too have shifted from a trivalent to a quadrivalent vaccine.
  3. Since the vast majority of influenza vaccines manufactured were trivalent till recently, the World Health Organisation (WHO) used to recommend two A subtypes and one B subtype, plus an optional fourth strain (the other B virus strain).

Benefits of Quadrivalent Vaccine

  1. The quadrivalent vaccine will contain four influenza virus strains (two A subtypes and two B subtypes — H1N1 and H3N2, and Victoria and Yamagata respectively).
  2. The viruses used in the vaccine are killed and this eliminates the possibility of the virus in the vaccine itself causing infection.
  3. In India, the vaccine will be available as a single dose pre-filled syringe
  4. Eventually, it will be available in a vial for public health use.

Incidences of different Strains

  1. In the case of H1N1, there are two strains — California and Michigan — that cause influenza. In India, the Michigan strain was earlier circulating and has been replaced by the California strain.
  2. For 2018, the WHO has recommended the Michigan strain for the southern hemisphere, including India.
  3. Each year, the vaccine changes to reflect the different strains in circulation.
  4. Year-round, scientists across the globe track, analyze and classify the viral strains causing illness.

 Indian context

  1. Despite the high number of infections and mortality each year, India does not have in place a national policy for influenza immunization.
  2. Pregnant mothers, children aged below five and young people with asthma, cardiovascular disease, diabetes and high blood pressure are at a greater risk of infection and death.
  3. The Ministry of Health issues only H1N1 vaccination guidelines for different vulnerable groups including healthcare workers.
  4. If we want to reduce the influenza burden in adults, then we must target children as they act as reservoirs.

Back2Basics

Influenza

Influenza is a virus that actually has hundreds of different strains. The virus mutates frequently, but the strains are classified into one of three main categories—A, B, or C.

Influenza A is the group that most commonly causes illness in humans.

  1. All influenza A viruses are further broken down into H and N subtypes. So, any influenza virus that is described as “H#N#” (such as H1N1) is an influenza A virus.
  2. There are 16 H subtypes and nine N subtypes, but only three combinations have actually caused highly contagious illness in humans.
  3. Other combinations have been found to infect other species (such as birds and pigs), but they have not caused widespread human infections.
  4. The three combinations that cause almost all outbreaks of the flu in humans are H1N1, H2N2 and H3N2.
  5. Even in these subtypes, the influenza virus can mutate and change each year. For this reason, influenza viruses are also named using:
  • The host of origin (swine, chicken, etc., or no host if it is of human origin)
  • The geographical location of origin (Hong Kong, Alberta, etc.)
  • Strain number
  • Year of discovery (or isolation)

Influenza B

  1. Influenza B is less common but still causes outbreaks of seasonal flu.
  2. One or two strains of influenza B are included in the seasonal flu vaccine every year to protect people from the strain(s) that researchers believe are most likely to cause illness during the upcoming flu season.
  3. The quadrivalent flu vaccine contains two strains of influenza B but the traditional trivalent flu vaccine only contains one.
  4. Influenza B is not broken down into subtypes like influenza A is, but it is broken down into individual strains.
  5. Typically, two strains of influenza A and one strain of influenza B are included in the seasonal flu vaccine. Quadrivalent flu vaccines contain two strains of influenza A and two strains of influenza B.
  6. Influenza B can cause outbreaks of seasonal flu but they occur less frequently than outbreaks of influenza A.
Health Sector – UHC, National Health Policy, Family Planning, Health Insurance, etc.
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