Post Content

Before drug manufacturers ship vaccines to distributors they, along with the Food and Drug Administration (FDA), always test them to determine that they meet all safety and efficacy standards. As part of its quality assurance program, manufacturer Sanofi Pasteur, performs additional routine, ongoing tests of their flu vaccines to ensure that they continue to meet required specifications after they have been distributed health care providers.

This week, after performing these tests, Sanofi Pasteur notified Centers for Disease Control (CDC) and the FDA that the antigen content in a batch (known as a "lot") of syringes intended for children 6 months through 35 months of age distributed to providers in November, had dropped below a pre-specified limit making them slightly less potent.

Consequently, Sanofi Pasteur tested additional lots and found that three others also had an antigen content that had fallen below pre-specified limits. This means that doses from these four vaccine lots no longer meet the specifications for antigen content. Therefore, Sanofi is conducting a voluntary recall of these affected lots and has asked providers to return any vaccine they may have from these lots to the manufacturer.

The affected vaccine met all specifications at the time of release and both CDC and FDA have determined that there are no safety concerns for children who received this vaccine. Parents of children who received vaccines from the recalled lots do not need to take any action other than make sure their child receives their second dose if they have not already. There is NO need to revaccinate children who have received vaccine from these lots. The antigen content in the affected lots of vaccine is only slightly below the specification limit and experts expect it to still be effective against the H1N1 flu.

This drop in antigen content below the required specification only occurred in Sanofi Pasteur’s pediatric H1N1 monovalent vaccine in 0.25 mL pre-filled syringes. The same vaccine packaged in other forms, such as pre-filled syringes for older children and adults and multi-dose vials, continue to meet specifications.

For additional information please see CDC’s Questions and Answers related to the withdrawn vaccine at http://www.cdc.gov/h1n1flu/vaccination/syringes_qa.htm

We encourage all residents to utilize the comments section on this blog to engage with us and each other. While we cannot respond to every comment or question directly, we find them very helpful to understand your questions and concerns and plan for future posts.

Written By:


Communications Office

Recent Posts

A Taste of India for Special Occasions! posted on Mar 27

A Taste of India for Special Occasions!

At WIC, we are very fortunate to have so many staff members from different countries and cultures.  In this week’s blog, Kinnari Chitalia, RD, LDN, CLC, Nutritionist at the Dorchester North WIC Program, shares a favorite recipe that can be made at any time, but   …Continue Reading A Taste of India for Special Occasions!

Working to Eliminate Health Disparities Among LGBT People posted on Mar 27

This week marks the commemoration of National LGBT Health Awareness Week. At DPH this is not only an occasion to celebrate the strides that we as a Commonwealth have made in reducing disparities in health care and health outcomes among people who identify as lesbian,   …Continue Reading Working to Eliminate Health Disparities Among LGBT People

Weekly Flu Report, March 27, 2015 posted on Mar 27

The latest weekly flu report shows a slight decrease in rates of flu-like illness in the Commonwealth over the past seven days, which is consistent with what we would expect to see at this point of flu season. Flu does however continue to be present   …Continue Reading Weekly Flu Report, March 27, 2015