H1N1 swine flu nasal spray vaccine (LAIV) recalled in US by AstraZeneca’s MedImmune

4.7 million doses of nasal spray version of H1N1 swine flu vaccine by AstraZeneca P.L.C.’s MedImmune unit have been recalled in US because tests showed a decline in potency.

4.7 million doses flu vaccine recalled involved 13 lots of Influenza A (H1N1) 2009 Monovalent Vaccine Live, Intranasal due to a slight decrease in potency.

The slight decrease in 13 lots of intranasal influenza A (H1N1) 2009 monovalent vaccine live potency is expected to have little, if any, impact on the response to vaccination, MedImmune said in a press release.

Revaccination is not recommended because intranasal influenza A (H1N1) 2009 monovalent vaccine in the affected lots is still expected to be effective in stimulating a protective immune response.

Intranasal influenza A (H1N1) 2009 monovalent vaccine doses were well within potency specifications at the time they were distributed, and in fact, some of the doses being recalled are actually still within required potency limits.

However, MedImmune has recommended that all lots marked with an expiration date of between January 19 and January 26,2010 not be used.

Officials believe most of them were administered in October and November when the product would have still been at full potency.

MedImmune still has 3,000 doses of the vaccine affected by the recall, but no one knows how many are in warehouses around the country.

MedImmune received approval from the U.S. Food and Drug Administration for its live attenuated influenza vaccine (LAIV) against the novel H1N1 influenza virus, on Sept. 15, 2009.

The LAIV vaccine is indicated for the active immunization of individuals 2-49 years of age against influenza caused by pandemic (H1N1) 2009 virus.

LAIV is different from the injectable influenza vaccine in that it contains live vaccine virus strains that are weakened so as not to cause the flu.

LAIV is delivered into the nose, where the influenza virus usually enters the body, rather than by injection.

LAIV prompts the body to begin mounting an immune response after the first dose.

MedImmune currently holds a license for its seasonal and H1N1 LAIV products in the United States.

The US health authorities ordered for approximately 40 million doses of LAIV for the H1N1 strain have been placed to date.

MedImmune’s development of LAIV for this strain of H1N1 began at the end of April, when the company received the new viral strain from the U.S. Centers for Disease Control and Prevention (CDC).

A week ago, Sanofi Pasteur, the vaccine division of the French drug maker sanofi-aventis, recalled 800,000 pre-filled syringes of Influenza A (H1N1) 2009 Monovalent Vaccine after finding that vaccine doses meant for kids lost their potency.

Sanofi Pasteur’s Influenza A (H1N1) 2009 Monovalent Vaccine is an inactivated influenza virus vaccine indicated for active immunization of persons 6 months of age and older against influenza disease caused by pandemic (H1N1) 2009 virus.

Sanofi Pasteur reported the potency findings to the government officials and did a voluntary recall.

Sanofi Pasteur is the No. 1 manufacturer of flu vaccines in the world. It makes flu vaccine at sites in France and in Pennsylvania.

In November, GlaxoSmithKline recalled a lot of its H1N1 swine flu vaccine in Canada following complaints of adverse reactions from the vaccine, reports said.

GlaxoSmithKline has asked that the October batch of H1N1 swine flu vaccine be taken out of circulation because it produced serious and immediate anaphylactic reactions in one out of 20,000 vaccinations, compared with one out of 100,000 in other shipments.

Following this, Canada’s H1N1 flu vaccine manufacturer has asked the provinces to temporarily discontinue vaccinating Canadians from a lot of vaccine shipped in October due to a higher risk of adverse reactions.

GlaxoSmithKline has asked several provinces to set aside the 170,000 doses from the questionable batch.

More than 100,000 doses of the H1N1 vaccine are being withdrawn across the country.

GSK said the batch recall is a precaution an they will investigate to see whether there is something wrong with the batch.