Vaccination: What do scientists think?

Just 25,000 vaccinations take place each year in the US, one in four of which are routinely ordered. Vaccination coverage in the US is well below that of comparable Western countries (such as France,…

Vaccination: What do scientists think?

Just 25,000 vaccinations take place each year in the US, one in four of which are routinely ordered. Vaccination coverage in the US is well below that of comparable Western countries (such as France, where 84% of all children have received all the recommended vaccines by age 15).

In the US, the consensus view among infectious disease specialists is that many vaccines offered are life-saving and that current vaccination rates are unacceptable. In recent years, a growing group of new and more sophisticated clinical trial evidence-based research findings has found evidence of an over-use of vaccines – not enough vaccines in the correct sequence and in the right dosages.

However, the evidence as to whether highly touted “vaccine boosters” work has been mixed at best, and it is unclear if they offer any kind of benefit. For example, certain no-show boosters can lead to autoimmune disorders and higher adverse effects (such as hepatitis C infection).

Weighing in on the debate, a new study published in the peer-reviewed journal Science concluded that while vaccine adjuvants may be effective at boosting the effect of an otherwise burdensome vaccine such as rotavirus, it is unclear whether they are effective as single vaccines. Moreover, few vaccines contain adjuvants, and even if some did, it would be costly to acquire and administer them all in higher doses to all recipients.

Several publications have reported the results of other large studies, and while they reveal no conclusions as to whether adjuvants increase or reduce the odds of adverse events among vaccine recipients, neither group casts doubt on the therapeutic efficacy of vaccines. An additional issue, however, is the reliability of such studies, many of which do not randomly assign participants to receive adjuvants or placebo (or “placebo”).

Adjuvants are engineered ingredients added to vaccines to make them more effective by increasing their uptake in the central nervous system. The current consensus amongst infectious disease experts is that among vaccines containing an adjuvant, these do not boost the rate of vaccination to acceptable rates or to the effect they had been anticipated.

Specifically, research has found a small, positive response among vaccinated people and a significant increase in the use of adjuvants that have had no previous epidemiological benefit. The vaccines studied included three that were widely touted to boost vaccination rates by providing added protection from influenza, whooping cough and rotavirus, in addition to the human papillomavirus, and one each with M&M flus and varicella. Other studies have reported a modest effect of adjuvants at work for vaccines containing CCR5 receptors, which protect against meningitis, and human papillomavirus (HPV), for which vaccination is advised for all girls who begin sexual relationships after the age of 13.

The findings from the newer studies, however, have not translated into value or a positive recommendation that all vaccines use adjuvants. And this is because many of the older, randomized controlled clinical trials, such as the CDC’s National Immunization Survey for the month of February, 2009, and others, did not ask how many vaccines were included or given. Research studies, whether designed as randomized trials or not, should provide answers, indicating if the desired effect occurred. But the long-term available data on US vaccination rates appear to suggest that when a new vaccine becomes available, public health authorities, including public health professionals and members of the news media, tend to consider these new vaccines as seen, “ready for prime time.”

While there are risks associated with vaccination, neither vaccinated nor unvaccinated people seem to be inherently at greater risk of becoming infected than their peers, and one of the critical ingredients in vaccination is the elimination of harmful infectious agents. Any new vaccine proposed must meet these objectives in order to gain broad acceptance. Unfortunately, there seems to be a case for making “vaccine boosters” more widely used. In addition to their non-randomized efficacy, there is evidence that the adjuvants act primarily by facilitating the uptake of vaccines to the central nervous system, a domain of immunology that is not well understood, and that their use would not add to the number of injectable vaccines.

For example, vaccination rates did not increase significantly in the Philippines after it instituted a policy in 1997 for delivering a vaccine booster. In addition, the late 1990s sees a small, positive effect among vaccinated people and an increase in the use of adjuvants in vaccines containing Rotavirus. These studies may in fact be referring to Rotavirus vaccines containing adjuvants, which are another way to increase vaccine coverage but are designed to enhance a vaccine’s uptake rather than pose an additional threat to non-vacc

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