Vaccine Maker Downplays Link To Side Effects

Vaccine Maker Downplays Link To Side Effects

September 20th, 2011 // 12:57 pm @

Three months ago, the FDA issued a harsh warning letter to CSL, a big maker of flu vaccines based in Australia, as a follow up to a March 2011 inspection. And that visit generated a 483 report showing that CSL had no idea how to properly conduct an investigation to determine why fevers and convulsions were reported after children were vaccinated with its Fluvax vaccine

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Now, though, a group of researchers may have solved the problem. They report using deoxycholate as a virus-splitting agent may have been the culprit. And they noted that clusters of adverse events following immunization were previously linked to other flu vaccines that used deoxycholate in Europe and Canada. CSL is apparently one of the few vaccine makers to use the chemical.

“While there may be other causes, the use of deoxycholate should be further explored,” the researchers write in the Medical Journal of Australia. “Comprehensive and timely investigations of (side effects), especially those involving children, are necessary to prevent their recurrence and to maintain public confidence in vaccination programs.”

To reach their conclusion, the researchers reviewed two studies and determined that limited data…suggest that the CSL vaccine “may have been, at least intermittently, associated with increased rates” of fever in children before 2010. One study indicated that that 22.5 percent of children under three years old suffered a fever after receiving CSL’s 2005 flu shot, and the second showed that 39.5 percent of children were feverish after getting the 2006 version.

Also, a clinical trial in the US two years ago found that 37 per cent of children between the ages of six months and three years old who received a CSL flu shot experienced fever, compared to 14 per cent given a rival vaccine that used a different splitting agent. Interestingly, the FDA wrote in its June warning letter that CSL failed to review virus splitting as a possible cause (read here). Nonetheless, the researchers write that fingering deoxycholate remains speculative.

Consequently, CSL pooh-poohed the findings. “The MJA perspective is interesting but it doesn’t add anything new to our ongoing investigations,” a spokeswoman tells The Australian. “Until we can explain what happened in 2010 and can be confident of preventing a recurrence in future seasons, we will continue to fully support the restricted use of our influenza vaccine in children.”

The vaccine maker maintains the “interaction” of swine and seasonal flu viruses used to make Fluvax likely contributed to febrile seizures in one in every 100 young children vaccinated last year. However, as the paper writes, the same viruses – selected by the World Health Organization for global vaccine production – had been used by other drugmakers without causing the same side fevers in kids. Perhaps CSL would have noticed this had the company known how to investigate problems in the first place.

Source: Pharmalot

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