Covid Vaccination one dose or 2 II
There is evidence from Israel that one dose of the Pfizer vaccine is less effective than was suggested by the few person-days of evidence in the phase III trials. In Israel “over 12,400 have people tested positive for coronavirus after receiving vaccine shots” Israeli health officials estimate that one shot is about 50% effective after 14 days . The control group is not matched, it’s not a randomized trial, but it is evidence that the second dose provides benefits on the order of the benefits of the first and is evidence against my proposal to delay the second dose.
Maybe vaccinated individuals engage in riskier behavior? Whereas the original test subjects (who did not know if they had been given the true vaccine) did not do so.
The vaccine was not 100% effective, even at two doses. Back before we had trials, people were saying even a 50% effective vaccine would get emergency approval, all things considered. These numbers would still be at that criteria.
January 20, 2021
Coronavirus
Israel
Cases ( 570,503)
Deaths ( 4,144)
Deaths per million ( 451)
———————————–
July 4, 2020
Coronavirus
Israel
Cases ( 29,170)
Deaths ( 330)
Deaths per million ( 36)
Having apparently approached a containment of the coronavirus in June, the Israeli government incautiously opened schools and businesses, and the result has been a persistent community infection spread contributing to what are now 570,503 cases in the small country as compared to 88,557 in all through all of mainland China. Israel unfortunately now has more than 6 times the number of coronavirus cases in mainland China. Paul Krugman noticed the Israeli “disaster” on September 14 when there were 160,000 coronavirus cases.
Data to ponder: the 5% of patients in the 95% immunized group experience on (zero) deaths at last look.
All important question about the efficacy of one dose: how many people in the 50% immunized group (one dose) who get infected will get very sick or die? If only half as many as non-immunized: that leads to one policy. If only one-twentieth as many severe illnesses and/or death: that leads to a very different policy of distribution.
https://marginalrevolution.com/marginalrevolution/2021/01/we-will-get-to-herd-immunity-in-2021-one-way-or-another.html
“To understand how bad we are failing compare with flu vaccinations. Every year the US gives out about 150 million flu vaccinations within the space of about 3 months or 1.6 million shots a day. Thus, we vaccinate for flu at more than twice the speed we are vaccinating for COVID! Yes, COVID vaccination has its own difficulties but this is an emergency with tens of thousands of lives at stake.”
The evidence for the efficacy of the first dose of the Pfizer vaccine is definitely not as strong as we would like, but I’m not sure the articles cast all that much doubt on the efficacy of first doses. The efficacy of first doses in the Pfizer study was 52% if you count all infections between first and second doses, but this presumably understates the efficacy of one dose because for the first 10 days or so people in the treatment group are still susceptible. (I think you made this point in your first post.) This seems to be more or less what the Israeli authorities are reporting.
If this interpretation is right, I think first doses first should still be on the table, although I agree we need to keep close track of outcomes and be prepared to change course if the data suggests one dose is less effective than hoped.
Hey Eric:
Are the powers to be in Israel publishing any study they have done showing the results of their study? If not, this is like the NYT reporting on what the CDC said.
Eric:
My point also is . . . we went through a period of time when people and even authorities with the appropriate backgrounds proclaimed certain drugs or certain drugs in combination with other elements would work and found the results in many cases to be unacceptable. The NEJM reported a trial of ~14,000 finding the 1st dose of Pfizer mRNA to have 52% efficacy. If Israeli authorities find it to be far less, then they should stop the vaccination process and move to a different drug which I believe may become impossible to do with a continuation of the Pfizer mRNA as it may conflict with a different drug. I also think someone is positioning themselves. Pfizer has much to lose if they made this up.
On the other hand, drug trials generally go on for a year. We were in a situation where this (these) trial(s), as reported by the NEJM, was (were) pushed through faster than what the newly minted 21st Century Cures Act would have allowed. Israeli medical authorities will have to decide rather quickly what they are going to do. If they continue, then this is a small concern on their part.
Half century of direct experience in the field turned out to be worth something after all. Advantage, Tony Fauci..
Eric. I am relying on newspaper reports (including quotes of the head of the Israeli vaccination effort). They are fairly detailed. The Guardian article is brief, but the Jerusalem Post article is detailed. Israelis with the data have estimates of effectiveness after 2 weeks of 1 dose of 30% 50% and 60% (no explanation of the wide range). In the phase III trial, the number would be 85 to 90% (based on few person days — roughly 40 infections with 4 among vaccinated once).
I think the numbers are different and in Israel they are looking at a much larger sample (more than 49 times as large).
I think the issue is whether the artificial control group in Israel is really comparable to the vaccinated sample (that is Israeli results not from a randomized trial).
Also yes Denis it is possible that 1 dose prevents severe disease even if people convert on the test. That is very important. I think it is not quite “all important”. Another important issue is whether people who had 1 dose transmit Covid (that is become asymptomatic carriers). This is a very hard question to answer, and it is important.
Finally, the phase 3 data are a bit different for the Pfizer and Moderna vaccines. In the article on the phase III Moderna trial the apparent effectiveness of 1 shot was mentioned. There is no real reason to suspect this, but it is possible that one dose of the Moderna vaccine is more effective than one dose of the Pfizer vaccine (again possible as in many things are possible — the evidence comparing trials is extremely extremely weak)
I think the UK is sticking to long interval between shots, so we will learn a lot more.
We are all guinea pigs now. Medical science depends upon the evolution of educated guess work and in situations of crises then embraces risk management before the second guess.
how about zero doses and going back to restart the whole pandemic response thing over again from the beginning:
South African SARS-CoV-2 variant escapes antibody neutralization — Researchers in South Africa have conducted a study showing that the novel 501Y.V2 variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has emerged in the country is able to escape theneutralizing antibodies that are elicited by previously circulating strains of the virus. SARS-CoV-2 is the agent responsible for the coronavirus disease 2019 (COVID-19) pandemic that is currently sweeping the globe, devastating public health and the global economy.The study found that the 501Y.V2 lineage also conferred complete escape from three classes of therapeutic monoclonal antibodies.Penny Moore from the National Health Laboratory Service (NHLS) in Johannesburg and colleagues say the findings highlight the possibility of re-infection among people presumed to have acquired some degree of immunity due to previously having had SARS-CoV-2.The findings also have important implications regarding the effectiveness of certain vaccines and therapeutic strategies that are undergoing development. A pre-print version of the research paper is available on the bioRxiv* server, while the article undergoes peer review.
this could give team Biden the opportunity to show they’re better than Trump, their hindsight advantage notwithstanding
Can we please remove the post from the fake news troll “SeaShell?”