Tuesday, October 27, 2020

Why There is Unlikely to Be a Vaccine That is Proven Effective for Seniors for a Long Time

Gary Cornell, who has a  Ph.D. in mathematics from Brown University and has been a visiting scientist at IBM’s Watson Labs and a program director at the National Science Foundation, explains why any vaccine introduced any time soon to battle COVID-19 will be of unknown efficacy for seniors (the most at serious risk from the virus).

He writes:

 The risk of both hospitalization and death from Covid 19 increase greatly with age. Approximately 80% of the deaths from Covid 19 are people over 65 (https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/older-adults.html). The unfortunate truth is that a vaccine that is proven highly effective for seniors is not likely for a very long time, unless we dramatically increase the number of seniors in current trials now.

Why? The gold standard to determine efficacy is a large, placebo-controlled, double-blind clinical trial. There are currently eight vaccines in large Phase 3 trials. But it is very unlikely, maybe even impossible, that any of these vaccine trials will give us definitive information about how effective these vaccines are for people over age 55 — well, unless they change how they are currently setup.

Why? To begin with, none of the four trials that have released their protocols are properly stratified. While they aren’t lumping seniors into the same group as the 18 to 55-year-olds, they should be using three groups i.e. one for each age decile: 55 to 64, 65 to 74, and 75 and older. To be sure, it’s possible to tease out information about how different strata of seniors react to the vaccine even if they are lumped together in one group. However, it likely would take more data because you have to tease out the information for each age decile from a larger group.

But the bigger problem is that even if these trials give us some information about efficacy for seniors, they are unlikely to tell us everything we need to know quickly enough unless we have a far larger number of participants over 55 than the current trials are enrolling. Why? Since Covid-19 can be so deadly in older people, they and the communities they live in have generally been taking better precautions than the general public against becoming infected with the virus SARS-CoV-2 that causes Covid-19. For example, the CDC reports (https://www.cdc.gov/mmwr/volumes/69/wr/mm6939e1.htm#T1_down) that, as of August, roughly speaking, the prevalence among people >75 years old is 1/15 that of people 18–55 years old. And, even if you lump all people over 55 into one group, it is roughly 1/3. And, of course, we are all hoping that prevalence among seniors has gone down significantly since August. But prevalence is what determines the time needed to have a statistically significant efficacy signal from a vaccine trial...

To summarize: given what I feel are the inescapable ethical issues in completing any placebo controlled study on seniors once you have a safe and effective vaccine based on trials in healthy 18–55 olds, we must enlarge the number of seniors in the trials quickly. Failing to do so means that we likely won’t know enough about how well the original vaccine worked in one or more age decile group of seniors. Your castle will be built on little if any foundation.

In other words, the phony "follow the science" government officials will likely be ordering up a vaccine that will have unknown efficacy for the one group that is of serious risk from COVID-19.

What a scam!


1 comment:

  1. None of these trials is placebo-controlled.

    While his point is generally correct, the lack of a true control group is the greatest ethical and scientific problem.

    Robert, you should make this clear in your commentary.