# 3504
Today we got a bit more information from the CDC during a teleconference held for reporters by Dr. Anne Schuchat, Director Nation Center For immunization and Respiratory Diseases, along with Dr. Jesse Goodman, Chief Scientist at the FDA, and Dr. Bruce Gellin, Director of the National Vaccine Program Office for the HHS.
The initial lots of pandemic vaccine for Americans are still being grown by 5 different companies, and clinical trials are expected to commence in the next few weeks.
These trials will test to see what dosage (amount of antigen) is required to provoke an immune response, whether it will take 2 shots or one, and whether an immune boosting adjuvant will be needed.
Until these questions are answered, we really won’t know how many people can be vaccinated this fall and winter.
Clinical trials are expected to take about 2 months to complete, which presumably puts us into early October before any vaccines would be approved for use.
On July 29th a special, off-cycle meeting will be held to discuss whether prioritization and `tiers’ make sense should vaccine supplies be severely limited.
Amid reports that some manufacturers, who are using the old egg-based technology to grow the virus, are seeing `suboptimal’ yields, the CDC’s Dr. Shuchat stated that they planned for `a variety of scenarios’ and that nothing they’ve heard yet leads them to believe that the yield won’t fall within the range they’ve anticipated.
Dr. Schuchat did caution, however, that vaccine manufacturing was always prone to `surprises’.
When asked if there was any concern over the possibility that vaccine supplies might be held up by the governments of countries where they are made (see Force Majeure) Dr Schuchat simply stated that they had contracts in place and that, “The CDC was not currently concerned.”
As far as the likely effectiveness of any pandemic vaccine, Dr. Schuchat said we’d have to look at the clinical trials for initial information, but that it will vary by host (with the elderly and immunocompromised perhaps seeing less effectiveness), and that it would have to be monitored over the course of the flu season.
Normally, a vaccine is considered to be pretty `good’ if it is protective 70% to 90% of the time. Some years, that percentage is considerably lower.
There are, obviously, more questions than answers right now about a vaccination program this fall. We won’t have a lot of the answers we are seeking until the clinical trials are completed sometime late in September or early October.
Regarding the return of the virus this fall, while Dr. Schuchat stated that influenza's are unpredictable, she made it clear that they expect a heavy flu season this year, and that it may start earlier than normal this year.
Unusually for influenza, H1N1 is still circulating during the hot and humid summer months, and there are concerns that it will pick up steam in late August and early September when schools go back in session.
Dr. Schuchat warns that the American public needs to take the pandemic threat seriously, and warned against complacency.
The CDC, she said, is concerned about this virus. She urged all Americans to be thinking ahead about things like how they will deal with a family member falling ill, or their workplace having to shut down temporarily.
The tone of today’s conference was one of `cautious optimism’ regarding the availability of a vaccine this fall.
Specific promises, however, were not made.
No firm delivery dates, no promise of how much vaccine would be available, and no estimate of how many people could be vaccinated over the winter.
While officials in some other countries continue to trot out vague promises of `vaccines for everyone’ and `a vaccine will be available in the fall’, the CDC has (prudently, in my opinion) refrained from making such assurances.
Yes, it’s a bit frustrating.
But given all the things that could go awry between now and October, it makes sense right now to make as few promises as possible.
