A drive to vaccinate the general population each year seems to have yielded mixed results. This might be due to the fact that people are losing faith in the validity of the vaccines.
Some reports on its efficacy, coupled with past problems and recalls have soured public opinion on the effects of yearly flu vaccines.
That is a problem which the CDC is trying to tackle. Lack of vaccinations could overwhelm flu hospitals and make flu season management chaotic.
But new reports seem to increase the diffidence people have towards yearly flu vaccinations.
Each year flu vaccines are formulated by taking what are considered to be the most prevalent new strains and making a 'mix' of them in the vaccines to give people better immunity.
But this year, the numbers tell a different story. The vaccines seem to have only a 55% effectivness, and what's worse, in elderly people that percentage has shown to be as low as 10%. This is alarming, since seniors are some of the most vulnerable in the population to the exposure of the flu virus and exhibit the more severe symptoms.
The vaccine's vulnerability stems from its Influenza A component. While effectiveness against Influenza B was still between 50 and 67%, those for Influenza A were much lower, and in seniors in some cases less than 10%.
What is at question then is the process that lead to the choice of strains. Is it still effective? or must it be re-designed? Or are viruses mutating in such a way that it is ineffective to try to guess the mixture of strain to be used in the vaccines?
All these questions are now front and center in the CDC's new effort to identify the problems and find solutions to the current vaccine crisis.
The Department of Health and Human Services in conjunction with the flu vaccine producers are trying to address the problem. But whatever new strategies and technology are being studied, the results of these next generation, more potent vaccines, might not come online for another ten years.
In the meantime, the CDC still urges elderly people to get vaccinated. In any case, a small degree of protection is better than none.
Some have argued that the vaccine's lack of efficacy is due to the elderly person's feeble immune system, which is not mounting a sufficient response to the vaccine. But this does not explain why the vaccine is effective against one strain, and not against the other.
One vaccine producer is proposing the adoption of a quadrivalent vaccine, instead of the current trivalent vaccine. The vaccines now in use are formulated against two Influenza A strains and one Influenza B vaccine.
Another initiative is the creation of gene based vaccines. Also there is a drive to move away from vaccine created in chicken eggs as a culture medium, since such culture is too lengthy in the case of a world pandemic, and in addition, bars people with known allergies to egg from being inoculated.
What the vaccine producing companies are trying to do however, is to come up with a universal vaccine, one that would not need a yearly adoption of influenza strains, but one that is effective every year for every Influenza type.
Source: CDC/ Daily Mail 2.22.13
No comments:
Post a Comment