Delta is one million times more transmissible than anything we have ever seen and will kill you if it even is within a mile of your nose. The vaccines don’t work worth crap, especially against Delta, unless we all get jabbed every day. Glue (not staple, that might leave gaps) at least 5 masks, three of which should be N95s, to your face. Build a portable plastic box that you can place over your body and take everywhere with you. Never get within 400 feet of another human being. That is the level of Delta/breakthrough terrorism we are being subjected to. Let’s try, in vain I am sure, to bring a little reality and sanity to the discussion.
First up, this research examined likelihood of infection and trajectory of viral loads for the original variant of concern, G614, among over 800 persons who had been recently exposed to someone with a CV-19 infection. The study was done in Washington state between March and August of 2020. It was published to give a baseline against which to compare the future variants. It is a nice prospective study trying to catch people at or before the moment of infection and ascertain what actually happens in terms of viral load. The participants were tested daily for 14 days and those who had a subsequent positive test after an initial negative one were included in the analysis.
97 people became infected. 42% had only one day of viral shedding and they had a median cycle number of 38.5. These people were obviously marginally infected and almost certainly never infectious. It is a joke to treat them as a case. Another 18% only shed for 2 to 6 days and had a median cycle number of 36.7. Also highly unlikely to be infectious. 31% shed for 7 days or more with a far higher viral load, as indicated by the median cycle number or 18.3. So about a third of the supposed cases were actually likely to be infected and infectious. On average the viral load was highest on the 3rd day of positivity and symptomatic persons had higher viral loads than did asymptomatic ones. The average cycle number for the asymptomatic group was over 36. Remember the nonsense about asymptomatic people spreading the virus, I can assure you that at an average cycle number of 36, these people weren’t infecting anyone. There was a median of only 1.4 days from the start of shedding to the end and a median of 9.7 days to clearance of the virus, or a negative test. What the research suggests is that most “infected” persons are infected for a short time, have small viral loads and very limited duration of shedding. There is your Alpha, Beta, Delta, whatever baseline, although I will caution again about the need to understand the point in a strain’s life cycle that it is being sampled. (Medrxiv Paper)
Now let us look at infections after vaccination in a study from Israel but in the period before arrival of the dread pirate Delta. This small study examined not just the viral load and shedding, but the location of the virus following breakthrough infection. The study was performed in the US and compared persons who became infected at various points in the vaccination process versus unvaxed individuals. Fully vaxed persons had much lower viral loads than those earlier in the vaccination process. Note the very low percents of any of the groups having culturable virus, which was lower yet in the fully vaxed cohort. A further interesting finding was that in some cases the virus was only detectable in saliva, consistent with a very transient “infection”. So overall what we observe here is that vaxed people who are supposedly positive, actually generally have low viral loads and reduced periods of shedding and almost no likelihood of viable virus; i.e. they are not very infectious. (Medrxiv Paper)
Now we get to the Delta period, with another study from Israel looking at viral loads of breakthrough infections, and also studying the impact of a booster dose. (Medrxiv Paper) There were 1910 infections among the unvaccinated, 9734 infections among those with full two dose vaccination and 245 with three doses. Although the vaccinated group initially had a much lower viral load compared to the unvaccinated, by six months after vaccination that difference in viral loads had disappeared. The third shot restored the difference.
And England published the 22nd Technical Brief on Variants, which again unfortunately does not have viral load or household transmission data. While the brief text says Delta has twice the hospitalization rate as Alpha, I don’t see that in the table. The death rate across variants is said not to be comparable for a reason given in a footnote and there is no reason in the footnote. Looking at the data, for those under 50, Alpha had an ER visit case rate of 4.2%, a hospitalization rate of 1% and a death rate of .1%. For Delta those percents are 3.2%, .7% and 0%. For the 50 and over group, Alpha’s rates were 9.8% for ER visits, 5.3% for hospitalizations and 4.8% for death. Delta comes in at 5.4%, 2.8% and 2.3%. (A note, I only use the data from ER visits and hospitalizations where it was clear it was for CV, not with it.) Comparisons may not be apt, given that there were likely more vaxed people during the Delta period. Looking at Delta vaxed/unvaxed data, I am summarizing only the fully vaxed versus unvaxed columns, and I will again emphasize that the unvaxed likely includes those with prior infection, which leads to an understatement of vaccine effectiveness. Assuming my phone calculator work is good, the case rates for under 50 fully vaxed for ER visits, hospitalizations and deaths are 2.7%, .54% and .06%. The comparable rates for the unvaxed are 4.1%, .97% and .05%. So for under 50 year-olds, the rate of ER visits is about 50% higher, hospitalization rate is a little less than doubled but the death risk is slightly lower in the unvaxed. For the 50 and over group, the fully vaxed rates are 4,9% for ER, 2.5% for hospitalization and 2% for death. For the unvaxed, the rates in that age group are 13.6%, 7.6% and 6.5%. So for older persons, vaccination has a much greater rate of protection against adverse outcomes from Delta. (UK Brief)
Finally, another Delta era study from Oregon, matching case rates among unvaxed and fully vaxed populations. The vaccine effectiveness was estimated at 73%. Note that while persons with prior reported infections were excluded from the unvaxed group, they did not test for antibodies. And this was purely looking at infections, not hospitalizations or deaths. (Medrxiv Paper)
So panic if you want to but I still believe that Delta has at best a marginal transmission advantage, results in less severe disease, and is being handled pretty well by the vaccines.
Join the discussion 5 Comments
When are you going to talk about ADE and “leaky vaccines”? There appears to be growing evidence that it is taking place and now both Sweden and Portugal are refusing Israelis (the most vaccinated population) entrance into their country.
I am not going to, because there isn’t any actual evidence that this is occurring. ADE is another one of those concepts that is thrown out there as a risk with no evidence. And that has nothing to do with a supposedly leaky vaccine. The evidence suggests that protection lessens because the adaptive immunity is reduced after a few months, not because there is some mutation that evades the vaccines. And that has nothing to do with why Sweden and Portugal are not allowing travel from most Israelis, that is because of the high case rates in Israel right now.
Do I read the report correctly if I conclude for now, that those over 50, who are fully vaccinated, and 6 or more months have elapsed since the last vaccination, that these folks might be well advised to go for the booster or 3rd shot?
Unfortunately, it does appear that effectiveness against infection lessens after 6 months. However, it appears to remain strong against serious illness. On the other hand, we need actual booster studies to demonstrate that they are effective and safe. Early evidence suggests they return a person to stronger adaptive immunity, but for how long?