the absence of an unvaccinated control group for vaccine testing. Obviously testing the Covid vaccine against the meningitis vaccine is not a relevant test in my opinion.
Is this the Oxford/AstraZeneca one? I understand the objection, but there is a reason they're using the meningitis vaccine. This is a key part of ensuring that the trial is blind, i.e. ensuring that participants don't know whether they've received the actual vaccine or a placebo. If the CV19 vaccine causes a bit of soreness/redness around the injection site, plus other mild symptoms... then ideally you want your placebo to trigger the same
apparent effects (whilst obviously still being ineffective against CV19). Whereas if people know or strongly suspect they've been given a placebo, then this obviously impacts the results.
Another issue if participants can determine whether or not they've received a placebo is highlighted in
this example from a US trial. The participant had no reaction at the injection site, so believes she received the placebo. She now wants the real vaccine because, as she rightly states, she put herself at risk in participating in the first place... but the likelihood is that she won't be allowed it, because they don't want to unblind the trial, and they don't want to prevent themselves from identifying any long-term effects. It's a bit of an ethical dilemma, as people given a placebo after volunteering for the trial now find themselves at the very back of the queue for the actual vaccine.