Potency worries prompt GSK flu vaccine recall

To cap off one of the least effective seasons for flu vaccines in recent memory, vaccine producer GlaxoSmithKline ($GSK) announced the recall of all remaining doses of a quadrivalent, affecting roughly 1.7 million jabs.

Citing potency concerns, the U.K.-based drugmaker wants back all of its FluLaval Quadrivalent Thimerosal-Free vaccines in prefilled syringes, stating that over time, the vaccines can become less effective. In routine testing, GSK found that the vaccine's potency could be found to hit below required level. However, the drugmaker added that 99% of the drugs were distributed in 2014 with appropriate potency, AP reports. Glaxo is unsure how many doses remain unused.

The doses were produced at a troubled plant in Quebec City, Canada, FiercePharmaManufacturing reports, which has attracted FDA attention and a warning letter questioning the quality of the FluLaval vaccine. The regulator cited problems with purified water at the plant, and GSK eventually suspended production to investigate "irregular results" in quality control monitoring.

In an interview with FiercePharmaManufacturing, GSK spokeswoman Anna Padula said the company believes the potency problem is unrelated to the manufacturing issues for which it got the warning letter, saying that it was "premature to comment on the potential root causes" and that the company is investigating.

Potency and manufacturing issues aside, vaccine producers as a whole faced another issue during this year's flu season. After distributing vaccines containing the wrong strain of flu compared to what was actually circulated, effectiveness fell off a cliff for the year. The U.S. CDC reported that flu vaccines were just 19% effective in preventing medical visits for the season, compared to around 50% over the last three years.

Glaxo, however, was able to notch a 25% sales increase for Fluarix and FluLaval before things went south, raking in £251 million for 2014.

That's sure to be good news as the drugmaker has staked a lot on the success of its vaccines. After completing its $7.1 billion asset swap with Novartis ($NVS)--sending its oncology assets to Basel and purchasing the Swiss drugmaker's vaccines--it's counting on the division to deliver 14% of sales moving forward.

- read the AP story
- here's FiercePharmaManufacturing's take