Table 4.

Relevant topics retrieved from tweets mentioning influenza virus vaccines (only interpretable topic compositions are listed).

Topic numbera	Topic compositions
1	mom, today, needles, doctor, nurse, gave, give, told, dad, baby, big, shot, giving, making, wanted, lady, sh*t, f*ck
2	reaction, hoping, sick, kids, allergic, eggs, made, egg, chicken, allergy, medicine, tea
3	flu, season, people, year, virus, immune, system, shot, epidemic, strain, stay, healthy, spreading, protect, remember
4	influenza, pregnant, risk, vaccination, national, recommend, women, immunity, free, safe
5	arm, sore, today, hurts, hurt, yesterday, damn, left, feels, side, bad, feel, stupid, throat, pain, ouch, killing, feeling, hurting
6	waiting, cvs, line, walgreens, pharmacy, free, wait, office, give, long, gave, spray, clinic, nasal, giving, people
7	sick, hate, shots, f*ck, sh*t, flu, needles, damn, today, nervous
8	work, office, day, today, free, morning, tomorrow, doctors, doctor, shot, good, school

^aCorresponding interpretations of these topics are in Table 5.