Skeptigirl, let's not get to insistent on sources for every comment made in the forums. Ivor made a remark in passing about the burden of colds in the USA; his source may not have been a specific scientific publication, but his link to the NIAID claim for this should suffice as reasonable evidence for his statement in the context of the discussion.
When a claim about something is strongly disputed, then the protagonists can put forward the case for the veracity of their respective claims, but I don't think a disagreement about how many people get colds should be a reason for two of my favourite posters to fall out.
I was tired of Ivor's unsubstantiated claims for good reason. I made a point of saying that particular unsubstantiated claim was minor. But since you and Ivor insist on defending his frequently unsubstantiated claims, then so be it. I am only going to review one page of Ivor's unsubstantiated claims. I have been in discussion after discussion with him and know he makes unsupported claim after claim.
One need only examine page one in this thread to reveal the pattern.
post 30
The way vaccination is sold to individuals at the moment is often by misleading them into thinking being vaccinated will protect them directly by a significant amount.
It displays a certain level of contempt for people to think they are too selfish and/or stupid to be persuaded by an honest argument for vaccination, which would highlight the benefits to the community over the individual.
False claims, no sources.
post 33
If only one person has been vaccinated in a population, anything less than 100% immunity merely extends the expected time before they get infected.
Realistically, vaccination only "works" if enough of the population get vaccinated. The lower the efficacy of the vaccine, the more people in the population need to be vaccinated for it to have a significant effect.
Then there are those vaccines that are pretty useless for prevention, such as the BCG, though supposedly this does reduce the risk of complications if you do contract TB.
False claims, no sources.
post 35
That's why I put "works" in quotes.
This page explains what I was thinking about. I was considering the number of cases in the population, as opposed to a vaccination providing immunity for a particular individual.
Sort of. It's really complicated, though.
Different vaccines all work differently, and the epidemiology of various diseases is all different from disease to disease. You have to look at each disease separately.
Back to the chickenpox vaccine, in Japan (where the vaccine was used sparingly) it looked (or was) over 90% effective with a single dose, and immunity lasted over 30 years.
In the US where it was used universally, the effectiveness dropped and vaccine immunity wanes more quickly. Because the vaccine works just well enough to slow down spread of the virus, but then you get something called "secondary vaccine failure"...where the immunity wanes because people aren't getting their immunity boosted by exposure to the wild virus.
But what's true for chickenpox isn't necessarily true for measles, or pertussis, etc. They're all different.
Interesting stuff, which
indicates that vaccination programs are generally implemented not because of the individual benefits for those vaccinated, but for the entire community.
I point out this quote is not from the source, it is from another post of Ivor's, I guess.
This source does not support Ivor's conclusions and his interpretation of this citation is a pretty good example of his less than logical thought processes.
What does the source actually say about the "purpose of vaccinations" and "individual protection"?
Most discussions of life-long protection focus on individual protection. This is an important consideration for any vaccine. However, we as a society derive far more benefit by seeking protection for all by eliminating exposure to infectious diseases.
(emphasis mine in the actual citation quote and in Ivor's quoted post)
What does the source actually say about,
"The way vaccination is sold to individuals at the moment is often by misleading them into thinking being vaccinated will protect them directly by a significant amount"?
For example, use of a cellular pertussis vaccines in Japan among 2-year-old children led to marked reductions of pertussis among younger children who were not targets for vaccination (20). Similar effects have been seen in the United States with Haemophilus influenzae type b and measles (21, 22). Any effort to induce life-long immunity requires that vaccines be used and used widely among targeted groups.
Ivor's logic? Because there was a reduction in a group not vaccinated, the vaccine must have been useless in the group actually vaccinated. Really? Then how did it work in the non vaccinated group?
What does the source actually say about,
"Realistically, vaccination only "works" if enough of the population get vaccinated. The lower the efficacy of the vaccine, the more people in the population need to be vaccinated for it to have a significant effect"? (emphasis mine)
When there are high levels of immunity in the population, the likelihood that a transmitting case will come in contact with a susceptible person is reduced, thereby resulting in indirect protection of the few remaining susceptibles, including those too young for vaccination, those with legitimate contraindications to vaccination, and those whose vaccination fails to protect them. While there is no absolute level of population immunity short of 100% that will guarantee elimination of disease transmission, it is clear that the higher the level of immunity, the lower the probability of significant transmission (19).
(emphasis mine)
What does the source actually say about waning varicella vaccine immunity?
Live attenuated viral vaccines are generally believed to induce long-term, probably life-long, protection among the great majority of individuals (9). Measles, mumps, rubella, and oral polio vaccines are in this category. Inactivated vaccines and toxoids usually induce shorter-term protection and require periodic boosters. Experience with a number of the newer inactivated vaccines, such as hepatitis B vaccine and enhanced-potency inactivated polio vaccine, is too limited to know the precise duration of immunity (15, 16). Immunologic memory, even in the absence of detectable antibody, may confer life-long protection.
In other words, nothing.
And what does Ivor also misunderstand from the source in his next post?
SUMMARY
Life-long protection from disease through immunization can be accomplished through individual or community protection. Individual protection is the goal for vaccination against diseases that have inanimate or animal reservoirs or that pose risks for certain populations. Community protection is the goal for vaccination against diseases that are transmitted only from human to human. Community protection afforded by childhood vaccines has been highly successful against measles, rubella, mumps, and polio. However, outbreaks of measles, rubella, and mumps continue to occur, primarily because of inadequate immunization of children under age 2. Simplification of vaccination regimens, provision of incentives to care providers and parents, and increased access to care should improve vaccination rates in the United States. Better protection requires better use of available vaccines. Eradication of disease through vaccination is the ultimate goal of community protection. Elimination of the infectious agent is the most effective means of achieving life-long protection. The World Health Organization's (WHO) smallpox eradication campaign eliminated a serious disease as well as the need for a vaccine with frequent and severe adverse reactions. The discontinuation of smallpox vaccination in the United States has produced a savings of over $3 billion. Polio has been targeted by WHO for eradication by the year 2000. The eradication of polio and the elimination of the need for polio vaccination in the United States should result in a savings of $110 million per year in vaccine costs alone. Strong United States support is crucial for WHO to reach its goal. Any of the vaccine-preventable childhood virus diseases could be eradicated with sufficient national and international will. Measles and hepatitis B should be high priorities. The ultimate goal of vaccination is life-long protection of all individuals. Any disease of sufficient public health importance to warrant routine vaccination is of sufficient importance to warrant eradication wherever judged to be possible.
(emphasis Ivor's)
That supposedly supports the claim,
"which indicates that vaccination programs are generally implemented not because of the individual benefits for those vaccinated, but for the entire community". (emphasis mine)
And then there is this claim in post #39,
"Yes, it does. Only if the vaccination leads to 100% immunity does the incidence of the disease become irrelevant."
Huh? So if the vaccine reduced the incidence of measles to near zero it isn't relevant?
In the same post Ivor claims after citing a source explaining how BCG vaccine benefits people in high prevalence TB areas,
"A figure of 50% on average does not seem very effective at preventing TB." Not only does he have a poor understanding of the citation he quotes, but if it were to be interpreted as he claims, he is saying a 50% reduction in a disease responsible for 2 million annual deaths worldwide is not useful!
That is page one. I don't have time to bother with the nonsense on pages 2-13 but anyone who cares to look won't have any trouble finding more of the same.
). 
