Pilate has a headache throughout chapter 2, causing him to treat Yeshua as he would not normally treat a prisoner. He also wonders if he has been poisoned in some way, which I see as tying back into the idea of being inoculated. Pilate is also named on p. 27 as "Knight of the Golden Spear," which I associate with needles as being a tool for poking. This sounds silly so far, but bear with me.
After Ivan is taken to the mental ward he is given injections numerous times to calm him down. The first is after he tries to jump out the window:
A hypodermic syringe flashed in the doctor's hands, and in a single motion the woman ripped open the bedraggled sleeve of Ivan's Tolstoyan shirt and grabbed his arm with unfeminine strength. There was a smell of ether, Ivan grew weak in the arms of the four attendants, and the agile doctor took advantage of the moment and plunge the needle into Ivan's arm. p. 59We see Ivan getting more injections on page 96 when the nurse notices him crying in frustration at his failed attempts to write what had happened, and again on page 142. Ivan receives this injection after the ward is upset when Nikanor Ivanovich arrives and makes a ruckus, and Nikanor is also soothed by an injection, along with all the other patients. The doctor's and nurses treat these (probably morphine) injections as an act of mercy to upset patients, but it offers no cure for their ailments.
As Ivan drifts off to sleep we revisit Pilate and the crucifixion of Yeshua. As I said before, the spears I related to needles, and here they are used as a means of relief to Yeshua, Gestas, and Dimas.
"Praise the merciful Hegemon!" he whispered solemnly and quietly pierced Yeshua through the heart. Yeshua shuddered and whispered, "Hegemon..." p 151-2Before the mercy killing, the soldiers also offer water on a sponge so they can drink. Although both are used for relief, the spears offer a more permanent (if violent) solution to pain, and release blood instead of injecting something into it.
Yeshua and Ivan are clearly connected by homelessness (Yeshua is called a vagrant by Pilate, Ivan's poet name, Bezdomny, means homeless), mental instability (Ivan is in a ward, Pilate calls Yeshua mentally ill), as well as both being rather simple-minded (Yeshua is not a stoic Jesus, but a more naive and straightforward character, the Master calls Ivan an ignorant man, and Ivan agrees). I'm interested in seeing how this parallel plays out in the rest of the novel.
On a final note, there is also a language of disease used in several instances, on page 54, "The skin on the doorman's face took on a typhoid tinge..." and on p 129, "a putrid malarial dampness had spread over the floor." The barman is told by Woldon that he will die of liver cancer in nine months, and advises against going to the hospital, because they can offer no cure.