Live attenuated influenza vaccine
Encyclopedia
Live attenuated influenza vaccine (LAIV) is a type of influenza vaccine. It is an attenuated vaccine. This is in contrast to most influenza vaccines, which are inactivated vaccine
s. Both forms of vaccine (live attenuated and inactivated) are typically trivalent. That is, they contain material from three different influenza virus
strains recommended by national and international public health agencies as most likely to be protective against seasonal influenza
in any given year. LAIV is sold under the trade name FluMist
in the United States
and Fluenz in Europe
.
.
), it is still a living virus, and may cause an infection
with complications in people with weakened immune systems or other underlying medical conditions. LAIV is recommended only for people 2–49 years of age, and is not recommended for people who have a weakened immune system, for pregnant women, or for people with certain chronic diseases. In contrast, inactivated virus vaccines contain no living virus, and cannot cause a live infection. Persons receiving LAIV may shed small amounts of the vaccine virus during the first week. People coming in contact with the vaccinated person are not considered to be at risk, unless their immune systems are severely weakened (bone marrow transplant recipients).
in the United States and Fluenz in Europe
. For the 2010–2011 flu season, FluMist was the only LAIV approved by the FDA for use in the USA. All other FDA-approved lots were inactivated virus vaccines. In September 2009 a LAIV intransal vaccine for the novel H1N1 influenza virus was approved and the seasonal intranasal vaccine was approved by the European Medicines Agency
for use in the European Union
in 2011, though distribution will not likely begin until 2012.
constructs each of the three attenuated virus strains that make up the vaccine is by combining gene segments from an attenuated master donor strain with gene segments coding for the hemagglutinin and neuraminidase from one of the currently circulating wild type viruses. It is the vaccine-generated immunity
against these specific hemagglutinin and neuraminidase components that is protective.
Inactivated vaccine
An inactivated vaccine consists of virus particles which are grown in culture and then killed using a method such as heat or formaldehyde.-Examples:Types include:* viral: polio vaccine and influenza vaccine...
s. Both forms of vaccine (live attenuated and inactivated) are typically trivalent. That is, they contain material from three different influenza virus
Influenza
Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae , that affects birds and mammals...
strains recommended by national and international public health agencies as most likely to be protective against seasonal influenza
Flu season
Flu season is a annually-recurring time period characterized by the prevalence of outbreaks of influenza . The season occurs during the cold half of the year in each hemisphere. Influenza activity can sometimes be predicted and even tracked geographically...
in any given year. LAIV is sold under the trade name FluMist
FluMist
FluMist is a nasal spray influenza vaccine manufactured by MedImmune, Inc. that was first introduced in 2003. It was the first and the only live attenuated vaccine for influenza available outside of Europe. It is also called live attenuated influenza vaccine . In September 2009 a LAIV intranasal...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Fluenz in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
.
Rationale
There is some evidence from clinical studies that LAIV is more effective than inactivated vaccine in young children.Administration
LAIV is administered intranasally, while inactivated vaccine is administered by intramuscular injectionIntramuscular injection
Intramuscular injection is the injection of a substance directly into a muscle. In medicine, it is one of several alternative methods for the administration of medications . It is used for particular forms of medication that are administered in small amounts...
.
Risks
Even though the virus in LAIV is attenuated (low in virulenceVirulence
Virulence is by MeSH definition the degree of pathogenicity within a group or species of parasites as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenicity of an organism - its ability to cause disease - is determined by its...
), it is still a living virus, and may cause an infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
with complications in people with weakened immune systems or other underlying medical conditions. LAIV is recommended only for people 2–49 years of age, and is not recommended for people who have a weakened immune system, for pregnant women, or for people with certain chronic diseases. In contrast, inactivated virus vaccines contain no living virus, and cannot cause a live infection. Persons receiving LAIV may shed small amounts of the vaccine virus during the first week. People coming in contact with the vaccinated person are not considered to be at risk, unless their immune systems are severely weakened (bone marrow transplant recipients).
Source of LAIV
MedImmune, LLC is one company that manufactures LAIV, which it sells under the trade name FluMistFluMist
FluMist is a nasal spray influenza vaccine manufactured by MedImmune, Inc. that was first introduced in 2003. It was the first and the only live attenuated vaccine for influenza available outside of Europe. It is also called live attenuated influenza vaccine . In September 2009 a LAIV intranasal...
in the United States and Fluenz in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. For the 2010–2011 flu season, FluMist was the only LAIV approved by the FDA for use in the USA. All other FDA-approved lots were inactivated virus vaccines. In September 2009 a LAIV intransal vaccine for the novel H1N1 influenza virus was approved and the seasonal intranasal vaccine was approved by the European Medicines Agency
European Medicines Agency
The European Medicines Agency is a European agency for the evaluation of medicinal products. From 1995 to 2004, the European Medicines Agency was known as European Agency for the Evaluation of Medicinal Products.Roughly parallel to the U.S...
for use in the European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
in 2011, though distribution will not likely begin until 2012.
Manufacture
MedImmuneMedImmune
MedImmune, LLC, headquartered in Gaithersburg, Maryland, became a wholly owned subsidiary of AstraZeneca in 2007. Since being acquired, MedImmune has remained a Maryland-based biotechnology development enterprise...
constructs each of the three attenuated virus strains that make up the vaccine is by combining gene segments from an attenuated master donor strain with gene segments coding for the hemagglutinin and neuraminidase from one of the currently circulating wild type viruses. It is the vaccine-generated immunity
Immunity (medical)
Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...
against these specific hemagglutinin and neuraminidase components that is protective.
See also
- FluMistFluMistFluMist is a nasal spray influenza vaccine manufactured by MedImmune, Inc. that was first introduced in 2003. It was the first and the only live attenuated vaccine for influenza available outside of Europe. It is also called live attenuated influenza vaccine . In September 2009 a LAIV intranasal...
- Comparing flu shot to nasal spray
- Influenza vaccine