December 11, 2009, 11:00 AM

Each week the Centers for Disease Control (CDC) analyzes information about influenza disease activity in the United States and publishes findings of key flu indicators in a report called FluView. During the week of November 29-December 5, 2009, influenza activity decreased over the previous week across all key indicators except for deaths, but most indicators remain higher than normal for this time of year. Below is a summary of the most recent key indicators:

• Visits to doctors for influenza-like illness (ILI) nationally decreased again this week over last week. This is the sixth consecutive week of national decreases in ILI after four consecutive weeks of sharp increases. While ILI has declined, visits to doctors for influenza-like illness remain elevated nationally.
• Influenza hospitalization rates have decreased across all age groups but remain higher than expected for this time of year. Though declining, hospitalization rates continue to be highest in children 0-4 years old.

• The proportion of deaths attributed to pneumonia and influenza (P&I) based on the 122 Cities Report increased over the previous week and has been higher than expected for ten consecutive weeks. In addition, 16 flu-related pediatric deaths were reported this week: 13 of these deaths were associated with laboratory confirmed 2009 H1N1, 2 were associated with influenza A viruses that were not subtyped and one was associated with a seasonal influenza B virus. Since April 2009, CDC has received reports of 267 laboratory-confirmed pediatric deaths: 224 due to 2009 H1N1, 41 pediatric deaths that were laboratory confirmed as influenza, but the flu virus subtype was not determined, and two pediatric deaths were associated with seasonal influenza viruses. (Laboratory-confirmed deaths are thought to represent an undercount of the actual number. CDC has provided estimates about the number of 2009 H1N1 cases and related hospitalizations and deaths. The increase in the proportion of deaths as other indicators are going down is not surprising as the occurrence and reporting of deaths usually lags behind that of other indicators.

Read the complete CDC H1N1 Update article.

Non-Safety-Related Voluntary Recall of Certain Lots of Sanofi Pasteur H1N1 Pediatric (0.25 mL, for 6-35 month olds) Vaccine in Pre-Filled Syringes Questions & Answers

December 15, 2009, 9:00 AM ET

Why are some lots of pediatric H1N1 vaccine manufactured by Sanofi Pasteur in pre-filled syringes being recalled from the market?

As part of its quality assurance program, the manufacturer, Sanofi Pasteur, performs routine, ongoing stability testing of its influenza A (H1N1) vaccine after the vaccine has been shipped to providers. Stability testing means measuring the strength (also called potency) of a vaccine over time. It is performed because sometimes the strength of a vaccine can go down over time. On December 7, Sanofi Pasteur notified CDC and FDA that the potency in one batch (called a “lot”) of pediatric syringes that had been distributed was later found to have dropped below a pre-specified limit. As a result of this finding, Sanofi Pasteur tested additional lots and found that three other lots that had been distributed also had an antigen content that, while properly filled at the time of manufacturing, was later measured to be below pre-specified limits. This means that doses from these four vaccine lots no longer meet the manufacturer’s specifications for potency. Sanofi Pasteur will send providers directions for returning any unused vaccine from these lots.

What does potency mean for the H1N1 vaccine?

Potency (or strength) is determined by the measurement of the concentration of the active ingredient (also called antigen) in the H1N1 vaccine.

Are there any concerns about safety of vaccines from these lots?

No. There are no safety concerns with these lots of H1N1 vaccine. All lots successfully passed pre-release testing for purity, potency and safety.

Should infants and children who received vaccines from these lots be revaccinated?

No. The vaccine potency is only slightly below the “specified” range. The vaccine in these lots is still expected to be effective in stimulating a protective response despite this slight reduction in the concentration of antigen. There is no need to re-administer a dose to those who received vaccine from these lots. However, as is recommended for all 2009 H1N1 vaccines, all children less than 10 years old should get the recommended two doses of H1N1 vaccine approximately a month apart for the optimal immune response. Therefore, children less than 10 years old who have only received one dose of vaccine thus far should still receive a second dose of 2009 H1N1 vaccine.

Other questions that are answered in this CDC article are listed below:

• What action(s) should parents of children who have received vaccine from the recalled lots take?

• What are the lot numbers affected by this recall?

• How many doses of the pediatric H1N1 vaccine are affected by this recall?

• Is the potency issue related to this recall isolated to just the pediatric H1N1 vaccine for 6-35 month olds?

• Were these lots of vaccine shipped after failing a required test?

• What is being done to notify providers who received vaccine from the affected lots?

• Where were the affected lots of vaccine distributed?

• For U.S. children 6-35 months old, what other options are available currently for vaccination against H1N1 influenza?

See last month's (Sep/Oct) OEHN Occupational Health Updates Newsletter which focuses on H1N1 and provides many helpful links.

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