“There is some data, not a lot but some out there, that show the first dose of the mRNA vaccines are about 90% effective but that it fades to the mid 60% range by week five.”
Do you have a link to the data showing 60% effectiveness by week five?
I can dig it up. It’s from a study out of Scotland if I recall. It was 35 days. But this only refers to the first shot. It does not include people who got 2 doses.
Also should be noted what we are actually measuring. They were measuring rates of hospitalization or death. So 90%+ reduction during the first 4-5 weeks, but reduction in hospitalization or death dropped to 60% range at day 35 among those who only got the first dose. It may have some biases e.g. who decides when to administer a patient to the hospital or when, vs sending them home for bed rest. So I am not wholly confident in these or any statistics related to covid.
The experiment used medical records covering 5.4 million people, or 99% of the Scottish population and focused on people who had received a single shot of either the Pfizer-BioNTech vaccine or the AstraZeneca-Oxford vaccine, the only two shots authorized in the UK.
One dose helped protect against hospitalization, with effectiveness peaking about five weeks after immunization at 84% effective at preventing hospitalization.
But the follow-up data available beyond that time is where it gets concerning. Effectiveness peaked and then began to decline, going from 84% effective in the fifth week to 61% effective the following week and then 58% beyond then.
It’s unknown whether that trend would continue beyond that, as that’s all the data the researchers had available to crunch in the study. But the findings suggest that protection starts to wane from a single dose after five weeks or so.