I remember a saying. With medicines, a cold disappears in seven days. Without, it takes a
week. Nature is the greatest healer and medical science tries to complement
it. For minor issues like cold, cough, fever, stomach upset, headache a person
can simply rest, and let nature take her own course. But doctors prescribe
medicines because of their training and patients lacking patience take them. Smart
bacteria have made many antibiotics ineffective. Clever doctors prescribe a
course long enough for a timely cure by nature.
B follows A, therefore A must have caused B. This is
called the post hoc fallacy. A village child hears the rooster crowing, and then
sees the sun rising. The child is certain; the sun rises because of the
rooster.
Did the medicine have any effect on your headache? To
answer you must ask: what would have happened to the headache had you not taken
the medicine? This is the purpose of a placebo. Take two friends with a bad
headache. (Maybe they drank together last night). Give a real pill to one, and an
identical looking dummy pill (placebo) to the other. If by evening, both heads
feel fine, then obviously the medicine was unnecessary.
*****
Other than nature and medicines, our mind is the third
doctor. If a person with a headache believes the pill would help him, even the
dummy pill may help. This is called the placebo effect. Placebo medication has been
shown to reduce pain because the patient’s belief activates the endogenous
opioid system in the brain.
God is an excellent example of a placebo. A student
sincerely praying before an exam, or a sportsman asking God’s blessings may
truly excel in their performance. God is a placebo medicine, because nobody has
seen the real medicine.
*****
Coming to the Covid-19 vaccines, you may have heard
that the trials are randomized,
double-blind and placebo-controlled. This is the gold standard without
which a vaccine will not be approved.
Half of the volunteers are given a real vaccine (experimental
group). The other half is given a placebo vaccine (control group). The
thousands of trial participants have no idea if they were given a vaccine or a
dummy jab. That is a single blind. But the doctors/ nurses who administered them
don’t know it either. That is why it is a double-blind trial. (The database has
the record of who is who).
To further remove any bias, the allocation of vaccines
and placebos is done randomly. Without blinding and randomization, a doctor may
be tempted to give placebos to healthy volunteers, and real vaccines to less
healthy ones. That could distort the results.
It is important a volunteer doesn’t know what he is
given. Oxford gives a meningitis/ septicemia vaccine as a placebo. That way
there is muscle pain, soreness, redness and swelling where the needle went in.
Of course, it will do nothing against the coronavirus.
*****
Giving a placebo is always an ethical issue. Informed consent
is obtained from all the participants. Everyone has a right to withdraw from
the trial at any stage. If someone who has received a placebo vaccine falls ill
with Covid-19, he will be treated on a priority basis.
In fact, for the success of the trial, it is critical
that a number of volunteers should fall
ill with Covid-19. Tomorrow I will explain why.
Ravi
सगळे मनाचे खेळ
ReplyDeleteलहान पण देगा देवा
ReplyDelete