Page 27 - Vaccines

The existence and the use of vaccines

vaccine because results so far have been sparse. Normally,
pharmacological testing is a rigorous and lengthy process.
After the pre-clinical trials in vitro or in laboratory and in
vivo on animals, the stages or phases of clinical trials on
human beings are as follows: phase I on healthy consenting
volunteers, to assess how the drug metabolises, how
tolerant the subject is to it and how if functions, phase II on
a small number of consenting patients suffering from a
disease, to see how the drug works, what the optimal
dosage is, and how best it may be employed therapeuti-
cally, phase III on a larger range of patients and often
internationally to assess the safety and the efficacy of the
drug, with patients consenting also to participate in a trial
where some will not receive the drug, but another or a
placebo, while some will receive the experimental drug, in
some cases with dosages varying, usually in “double blind”
trials where neither patient nor doctor knows in which
group each person is, and phase IV monitoring the efficacy
and safety of the drug once it is in commercial use in large
numbers of patients across the world—with strict protocols
and under the surveillance of ethical committees.21
The urgency created by the pandemic, recognised as
such only in the early months of 2020, and the need to
try to find an effective vaccine as soon as possible give
rise to the suspicion that the production of the vaccines
and the trials to evaluate them may have been excessively
hasty, perhaps excluding or shortening some of the
normal steps in clinical trials for vaccines or other
medicines, raising questions about safety and efficacy at
least with certain groups. That many people are anxious

21 Cf. E. Sgreccia, A. G. Spagnolo and M-L. Di Pietro (a cura di),
Bioetica: manuale per diplomati universitari della sanità (Vita e
pensiero, Milano, 2002), pp. 356–358.

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