[ashtonkem]

That’s really not true though. 99.9% effective might not be good enough for an Antarctic research base, but that’s a pretty unusual circumstance. We’d be thrilled if our current countermeasures against Covid were 99.9% effective; we would’ve ended this in 2020 if that were the case.

If I understand correctly, you can mathematically model how effective countermeasures have to be in order to suppress a virus with a given R0. Given that the measles vaccine is 93% effective and sufficient to suppress one of the most infectious diseases we’ve ever seen (R0 of 12-18), I think 99.9% would be in the overkill category.

[_0w8t]

Can you give a source for that 93% efficiency of measles vaccine? Accuracy for 2 digits is very suspicious. Measles symptoms depend strongly on nutrition deficiencies with insufficient vitamin C being especially bad. If that is not the case, one can be asymptomatic and then we never know about infection.

[eesmith]

https://www.cdc.gov/vaccines/vpd/measles/index.html

> The MMR vaccine is very safe and effective. Two doses of MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective.

Prevention of Measles, Rubella, Congenital Rubella Syndrome, and Mumps, 2013 Summary Recommendations of the Advisory Committee on Immunization Practices (ACIP) at https://www.jstor.org/stable/24832555

> One dose of measles-containing vaccine administered at age ≥12 months was approximately 94% effective in preventing measles (range: 39%–98%) in studies conducted in the WHO Region of the Americas (141,142). Measles outbreaks among populations that have received 2 doses of measles-containing vaccine are uncommon. The effectiveness of 2 doses of measles-containing vaccine was ≥99% in two studies conducted in the United States and 67%, 85%–≥94%, and 100% in three studies in Canada (142–146). The range in 2-dose vaccine effectiveness in the Canadian studies can be attributed to extremely small numbers (i.e., in the study with a 2-dose vaccine effectiveness of 67%, one 2-dose vaccinated person with measles and one unvaccinated person with measles were reported [145]). This range of effectiveness also can be attributed to age at vaccination (i.e., the 85% vaccine effectiveness represented children vaccinated at age 12 months, whereas the ≥94% vaccine effectiveness represented children vaccinated at age ≥15 months [146]). Furthermore, two studies found the incremental effectiveness of 2 doses was 89% and 94%, compared with 1 dose of measles-containing vaccine (145,147). Similar estimates of vaccine effectiveness have been reported from Australia and Europe (Table 1) (141).

No mention of vitamin C. Given that "After exposure, up to 90% of susceptible persons develop measles", it seems very unlikely that differences in vitamin C play an important role.

What are your sources? I found nothing on PubMed nor Google Scholar, though I did find that vitamin C is promoted to antivaxxers (eg, http://www.amcli.it/wp-content/uploads/2019/03/bmj-measles-f... ).

You write "depend strongly on nutrition deficiencies", which my cited article describes as "In low to middle income countries where malnutrition is common, measles is often more severe and the case-fatality ratio can be as high as 25%".

That's calorie deficient, but not specifically vitamin deficient.

[_0w8t]

Thanks for the links. “About 93%” is much more sensible then 93%. As for vitamins there was an old study [1] :

Child mortality due to measles is 200 to 400 times greater in malnourished children in less developed countries than those in developed ones. In addition, measles brings about consumption of nutrients in marginally nourished children, so they will also do worse if not supplemented during infection.

[1] https://www.karger.com/Article/Abstract/413843

[eesmith]

I strongly disagree - ashtonkem's description is quite sensible. I don't expect HN comments to be more precise than medical professionals.

That is, it's easy to find scholarly papers published by doctors which don't add the "about" like:

"Measles vaccine is highly effective, with 1 dose being 93% effective and 2 doses being 97% effective at preventing measles." from "Measles Outbreak — Minnesota April–May 2017" by authors from the Minnesota Department of Health, at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5687591/

"Based on the Centers for Disease Control and Prevention data, one dose of MMR vaccine is 93% effective against MeV, 78% effective against mumps virus (MuV), and 97% effective against rubella." by authors from The Ohio State University at https://www.pnas.org/content/pnas/118/12/e2026153118.full.pd... .

Yes, I already mentioned malnutrition as a known factor.

I asked for substantiation of your statement "insufficient vitamin C being especially bad."

You cited reference doesn't even mention vitamin C.

[_0w8t]

I was wrong with vitamin C, it was vitamin A deficiency that is correlated with severe symptoms, https://pubmed.ncbi.nlm.nih.gov/28282701/

And given that precise numbers like 93% is meaningless. One should either give the range or at least describe the population.

And it turned out 93% was not coming from the study in https://www.pnas.org/content/pnas/118/12/e2026153118.full.pd..., they just reference https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5863094/ , but that nowhere mention the number 93% and it’s abstract give much more sensible data:

Delivery of the two doses of vaccine needed to achieve >90% immunity is accomplished by routine immunization of infants at 9–15 months of age followed by a second dose delivered before school entry or by periodic mass vaccination campaigns. B

[eesmith]

Do you expect HN comments to use more accurate language than medical researchers use in published papers?

I don't.

So describing the difference between "93%" and "about 93%" as 'much more sensible', in this context, seems excessively nitpicky.

Even more so given that you got the wrong vitamin and it took you a couple of tries until you got the right citation.

[pessimizer]

Seeing people very critical of vaccine studies of a successfully eradicated disease that has had a long time since to evaluate that success aside a really generous benefit of the doubt given to vague claims about vitamin supplements makes me sad.

We can be observant and suspicious about the healthcare industry while also admitting that there is science being done. They manufacture vitamin C supplements, too. They make money whether you buy the regulated stuff or the unregulated stuff.

[ashtonkem]

In fact, there is a lot of money in supplements, lots of which aren’t FDA regulated to even work.