| Vaccine description | |
|---|---|
| Target disease | Influenza |
| Type | ? |
| Clinical data | |
| Pregnancy cat. | C |
| Legal status | ? |
| Routes | Intranasally |
| Identifiers | |
| CAS number | n/a |
| ATC code | J07BB03 |
| PubChem | CID n/a |
| (what is this?) (verify) |
|
| Influenza (Flu) |
|---|
| Types |
| Vaccines |
|
| Treatment |
| Pandemics |
| Outbreaks |
| See also |
Live attenuated influenza vaccine (LAIV) is a type of influenza vaccine.[1] It is an attenuated vaccine. This is in contrast to most influenza vaccines, which are inactivated vaccines. 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[2][3] 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[4] in Europe.
Contents |
There is some evidence from clinical studies that LAIV is more effective than inactivated vaccine in young children.[5][6][7]
LAIV is administered intranasally,[5] while inactivated vaccine is administered by intramuscular injection.
Even though the virus in LAIV is attenuated (low in virulence), 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.[8] 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).[1]
MedImmune, LLC is one company that manufactures LAIV, which it sells under the trade name FluMist in the United States and Fluenz[9] in Europe. For the 2010–2011 flu season, FluMist was the only LAIV approved by the FDA for use in the USA.[3] All other FDA-approved lots were inactivated virus vaccines. In September 2009 a LAIV intransal vaccine for the novel H1N1 influenza virus was approved[10] 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.[11]
MedImmune 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.