Post-vaccination menstrual cycle and associated pre- and post-menstrual symptoms
Of the total 5709 participants, 333(5.8%) developed irregularities of the menstrual cycle with 32.7% (109/333) having frequent cycles (every ≤20 days), 63.7% (212/333) prolonged cycles (>38 days), and 3.6% (12/333) intermenstrual bleed. A total of 301 out of 5709 participants (5.3%), noticed changes in the amount of bleeding during menstruation, with 151(50.2%) having excessive bleeding, 147(48.8%) scanty bleeding lasting for an average of 1-2 days with 0-1 pads/day, and the remaining three participants (0.99%) had amenorrhea for 3-5 months followed by heavy bleeding. Of these 301 participants, 130 (43.2%) had both irregular cycles with changes in the amount and duration of bleeding. The remaining 5408 (94.7%) participants observed no change in the amount of bleeding during menstruation post-vaccination. Furthermore, the irregularities of the menstrual cycle were significantly higher (p=0.011) in the COVAXIN group (7.2%) as compared to women who received the COVISHIELD vaccine (5.3%). Of the total of 1245 women who received the COVAXIN vaccine, 3.2% complained of frequent cycles (every <20 days) and 4.3% prolonged cycles (>38 days), which was significantly higher than the women who received the COVISHIELD vaccine (p=0.001). The mean±SD duration of bleeding and the number of sanitary pads used per day during menstruation in all the participants post-vaccination was 4.69±1.54 days, and 3.39±1.10 respectively. A total of 449(7.9%) participants observed the new onset passage of clots during menstruation. No statistically significant difference (p=0.346) was observed in the mean duration of bleeding pre- and post-vaccination in both the vaccine groups as depicted in Figure 2. A total of 721 (12.6%) participants complained of newly developed or worsening pre- and post-menstrual symptoms including severe dysmenorrhea with or without diarrhea (55.3%), severe lower backache (9.4%), lower abdominal dragging pain (18.0%), generalized weakness and body aches (8.9%), vaginal pain (1.7%) and increased vaginal discharge (0.7%) along with some non-specific symptoms in 5.96% participants including genital itching, burning sensation in the vagina during menses, increased hair loss, increased appetite, and insomnia during menstrual cycles. New onset or worsening of pre- and post-menstrual symptoms were significantly higher in the COVISHIELD group (p=0.031) with generalized weakness and body pains as the main complaint (p=0.001). The comparison of menstrual cycle patterns, and associated pre- and post-menstrual symptoms between women who received COVISHIELD and COVAXIN vaccines is depicted in Table 2.