Lancet: Efficacy, Safety & Immunogenicity Of Cell Based Vaccine

 

 

 

# 5318

 

 

Although we first heard of encouraging results from Baxter International’s phase III trial of their cell-based vaccine nearly a year ago (see Baxter presents results from Phase III study of Preflucel), today we’ve a study that appears in The Lancet providing us with additional details. 

 

The double-blind, placebo-controlled trial was conducted during the 2008-2009 flu season at 36 locations across the USA. Healthy adults (aged 18—49 years) were randomly assigned to either receive one injection of a placebo or a Vero-cell-culture-derived influenza vaccine.

 

Overall protective efficacy for antigenically matched influenza infection was determined to be 78.5%, which is comparable to what is traditionally expected from egg-based flu vaccines.

 

The Lancet, Early Online Publication, 16 February 2011

doi:10.1016/S0140-6736(10)62228-3

 

Efficacy, safety, and immunogenicity of a Vero-cell-culture-derived trivalent influenza vaccine: a multicentre, double-blind, randomised, placebo-controlled trial

 

Dr P Noel Barrett PhD  Gregory Berezuk MS,  Sandor Fritsch PhD, Gerald Aichinger MD, Mary Kate Hart PhD , Wael El-Amin MD, Otfried Kistner PhD , Hartmut J Ehrlich MD

(EXCERPTS)

Findings

The vaccine was well tolerated with no treatment-related serious adverse events. Adverse events were mainly mild and transient. An HI titre of at least 1:15 provided a reliable correlate of cell-culture-derived influenza vaccine-induced protection; no additional benefit was noted with titres greater than 1:30.

Interpretation

The data indicate that existing correlates of protection afforded with egg-derived seasonal influenza vaccines also apply to this vaccine.

Details on how this trial was conducted are available at clinicaltrials.gov  identifier NCT00566345.   A few excerpts follow:

 

The primary purpose of this study is to demonstrate the efficacy of an investigational Vero-cell derived influenza vaccine to prevent infection in an adult population with an influenza virus that is antigenically similar to one of the three strains in the vaccine.

 

All subjects will be randomized to receive a single 0.5 ml intramuscular injection from one of three lots of seasonal Vero-cell derived influenza vaccine or saline placebo. Subjects will be monitored for 180 days following vaccination for occurrence of adverse events. For determining antibody response, subjects will have one blood draw before and one blood draw 21 days after vaccination.

 

Preflucel, an inactivated split-virus vaccine, is only currently licensed for use in Austria and Czech Republic for the 2010 to 2011 influenza season. Baxter obviously hopes that additional countries will look favorably on these trial results.

 

Cell-based vaccines are being pursued because they may be used by people with egg-allergies, may be quickly produced, and are not dependent upon having the ready supply of hundreds of millions of eggs that are required for traditional influenza vaccine production.

 

The CDC, on the Flu.gov website, describes the process this way:

 

The new approach would use mammalian cells (kidney cells are often used) to grow the influenza viruses. Cell-based vaccine production could more easily meet "surge capacity needs" because cells could be frozen and stored in advance of an epidemic or developed rapidly in response to an epidemic. Cell-based vaccine production dramatically reduces the possibility for contamination and promises to be more reliable, flexible, and expandable than egg-based methods.

 

In place of eggs, cell-based vaccine production utilizes laboratory-grown cell lines that are capable of hosting a growing virus. The virus is injected into the cells where it multiplies. The cells' outer walls are removed, harvested, purified, and inactivated. A vaccine can be produced in a matter of weeks. Polio vaccine is currently produced using the cell-based method.

 

While both methods could produce an equally effective vaccine, egg-based production is physically limited by the availability of specialized eggs and alone may not be able to meet the accelerated demands of a global influenza pandemic. Cell-based vaccines offer the potential to increase production surge capacity and save lives.

  

The United States government has spent in excess of $1 Billion dollars over the past few years to accelerate the development and production of new influenza vaccine technologies.

 

It is well recognized that should another, more virulent pandemic erupt, our current vaccine manufacturing capacity would be woefully inadequate.

CIDRAP Reports On Cell Based Vaccine Trial

 

 

# 4965

 

Last night Robert Roos, news editor for CIDRAP, wrote a long and informative article on the results of a new study on cell-based vaccine production.

 

As an added bonus, you’ll find extended and insightful comments from CIDRAP’s director, Dr. Michael Osterholm.

 

Although hailed by proponents as the future of vaccine production, cell-based vaccines still have obstacles ahead. And as Dr. Osterholm points out, cell-based vaccine production may provide only an incremental improvement over egg-based technology.

 

Follow the link, this report is well worth reading it its entirety.

 

 

Trial answers some, not all, questions on cell-based flu vaccines

Robert Roos News Editor

Oct 6, 2010 (CIDRAP News) – A new report says that a cell culture derived influenza vaccine and a conventional egg-based vaccine both proved effective in a large international clinical trial, offering support for those who contend that cell-based vaccines should become an important part of flu vaccine supplies in coming years.

 

But it remains to be seen whether cell culture production, which has been discussed for years, is the wave of the future for flu vaccines. Some doubts persist as to whether it offers sufficient advantages in effectiveness and production time to replace the traditional egg-based technology.

(Continue . . . )

Novartis To Open Next Generation Vaccine Plant In NC

 

# 4068

 

The bottleneck in producing ample pandemic vaccine for the US, and the world, was caused in large part because we rely on the 50-year-old technology of growing antigen in chicken eggs.  

There are newer cell-based technologies on the horizon, but production facilities must be built, manufacturing problems solved, and these novel vaccines approved for use by the FDA.

Maggie Fox, Health & Science Editor for Reuters brings us word of a new factory in Holly Springs, North Carolina, that in a few years will hopefully be capable of producing as much as 150 million doses of adjuvanted cell-based vaccine within 6 months of a pandemic virus being isolated. 

 

The problems aren’t all technical or logistical, however.  

 

This cell technology is new, unfamiliar to most Americans, and the use of adjuvants in this country is currently viewed with suspicion.

 

The hope is, that we’ll come out of this pandemic season with a lot more safety data on the use of adjuvants.

 

Tens of millions of adjuvanted vaccines have already been delivered to the arms of people in Canada and Europe without apparent problems, and by the time this factory is ready to produce, it is hoped Americans may be more inclined to accept the product.

 

 

 

Next-generation flu vaccine plant to open in U.S.

Mon Nov 23, 2009 11:53am EST

 

* New factory first in U.S. to use cells to make flu shots

* Novartis hopes U.S. market will accept boosted vaccines

* First dose won't come before 2011

 

By Maggie Fox, Health and Science Editor

 

WASHINGTON, Nov 23 (Reuters) - Novartis (NOVN.VX) will officially open the first next-generation flu vaccine plant in the United States on Tuesday, but it will be years before it makes its first vaccine.

 

The factory in Holly Springs, North Carolina, will use batches of dog cells to grow influenza vaccine, instead of the chicken eggs widely used now. While the cell method is only slightly faster, it can be scaled up more quickly.

 

Federal advisers to the U.S. Food and Drug Administration last week asked for more safety data on another cell-based vaccine, one made by privately held Protein Sciences Corp. But U.S. officials said the new Novartis shot is not as experimental.

 

"I see them as totally different. The whole point of pushing on cell culture was increasing capacity and surge capacity," Dr. Bruce Gellin, head of the U.S. Health and Human Services Department's National Vaccine Program Office, said in an interview.

 

HHS spent $487 million helping Novartis build the plant, which was planned before the current pandemic of H1N1 swine flu.

 

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