Self-reported side effects of COVID-19 vaccines among the public

Figures & data

Table 1. Demographic profile of respondents (n = 901).

Demographic profile	M	(SD)	n	(%)
Age	37.0	(12.6)
18–30			344	(38.2%)
31–40			252	(28.0%)
41–50			167	(18.5%)
51–60			77	(8.5%)
61–70			57	(6.3%)
71–80			4	(0.4%)
Gender
Male			217	(24.1%)
Female			684	(75.9%)
Ethnicity
Malay			740	(82.1%)
Chinese			60	(6.7%)
Indian			67	(7.4%)
Others			34	(3.8%)
Education level
Graduate/ Post graduate degree			737	(81.8%)
High school/ Diploma			117	(13.0%)
Less than high school			47	(5.2%)
Comorbidities
Yes			222	(24.6%)
No			679	(75.4%)
Employment status
Employed			608	(67.5%)
Unemployed			293	(32.5%)
Previous COVID-19 infection
Yes			92	(10.2%)
No			809	(89.8%)
Type of vaccine received
Pfizer-BioNTech (Comirnaty ®)			381	(42.3%)
Sinovac (CoronaVac®)			117	(13.0%)
Oxford-AstraZeneca (ChAdOx1-®[recombinant])			127	(14.1%)
Others (e.g. CanSino/Johnson & Johnson/Sinopharm)			3	(0.3%)
Mixed vaccines			273	(30.2%)
Adverse effects
Yes			814	(90.3%)
No			87	(9.7%)

Table 2. Types of vaccines taken among mixed vaccines recipients (n = 273).

Types of mixed vaccines	n	(%)
Oxford-AstraZeneca (ChAdOx1-®[recombinant]) + Sinovac (CoronaVac®)	5	(1.8%)
Oxford-AstraZeneca (ChAdOx1-®[recombinant]) + Pfizer-BioNTech (Comirnaty ®)	70	(25.6%)
Sinovac (CoronaVac®) + Pfizer-BioNTech (Comirnaty ®)	197	(72.2%)
CanSino + Pfizer-BioNTech (Comirnaty ®)	1	(0.4%)

Figure 1. Side effects reported post COVID-19 vaccination based on types of COVID-19 vaccine (n = 901).

Figure 2. Side effects reported post COVID-19 vaccination based on vaccination dose (n = 901).

Table 3. Side effects reported post COVID-19 vaccination (n = 901).

Side Effects	n	(%)
Local side effects
Swelling at injection site	752	(83.5%)
Pain or soreness at injection site	628	(69.7%)
Redness at injection site	376	(41.7%)
Itchiness at injection site	271	(30.1%)
Swollen lymph nodes	117	(13.0%)
Systemic side effects
Headache	638	(70.8%)
Fatigue/ Tiredness	544	(60.4%)
Muscle weakness	529	(58.7%)
Diarrhea	451	(50.1%)
Nausea	450	(49.9%)
Skin rash	440	(48.8%)
Fever	424	(47.1%)
Chills and shivering	402	(44.6%)
Muscle pain	371	(41.2%)
Malaise	348	(38.6%)
Joint pain	371	(41.2%)
Constipation	285	(31.6%)
Dizziness	203	(22.5%)
Vomiting	176	(19.5%)
Insomnia	98	(10.9%)
Runny nose	71	(7.9%)
Cough	62	(6.9%)
Sore throat	51	(5.7%)

Table 4. The association between adverse effects post Pfizer-BioNTech (Comirnaty ®) vaccination and demographic profile (n = 381).

Demographic profile	Adverse effects				X^2	(df)	P value
	Yes		No
	n	(%)	n	(%)
Age					0.380^a	(379)	0.704
18–30	127	(93.4%)	9	(6.6%)
31–40	123	(95.3%)	6	(4.7%)
41–50	63	(88.7%)	8	(11.3%)
51–60	20	(90.9%)	2	(9.1%)
61–70	21	(95.5%)	1	(4.5%)
71–80	1	(100.0%)	0	(0.0%)
Gender					1.670	(1)	0.196
Male	83	(90.2%)	9	(9.8%)
Female	272	(94.1%)	17	(5.9%)
Ethnicity					1.381^a	(3)	0.710
Malay	295	(93.4%)	21	(6.6%)
Chinese	23	(88.5%)	3	(11.5%)
Indian	26	(96.3%)	1	(3.7%)
Others	11	(91.7%)	1	(8.3%)
Education level					2.530^b	(2)	0.282
Graduate/ Post graduate degree	296	(93.7%)	20	(6.3%)
High school/ Diploma	43	(93.5%)	3	(6.5%)
Less than high school	16	(84.2%)	3	(15.8%)
Comorbidities					0.830	(1)	0.773
Yes	91	(93.8%)	6	(6.2%)
No	264	(93.0%)	20	(7.0%)
Employment status					0.589	(1)	0.443
Employed	257	(93.8%)	17	(6.2%)
Unemployed	98	(91.6%)	9	(8.4%)
Previous COVID-19 infection							0.721^c
Yes	32	(91.4%)	3	(8.6%)
No	323	(93.3%)	23	(6.6%)

^a Independent T-test is performed.

^b Pearson Chi Square test is performed.

^c Fischer exact test is performed.

Table 5. The association between adverse effects post Sinovac (CoronaVac®) vaccination and demographic profile (n = 117).

Demographic profile	Adverse effects				X^2	(df)	P value
	Yes		No
	n	(%)	n	(%)
Age					−0.823^a	(115)	0.412
18–30	39	(70.9%)	16	(29.1%)
31–40	24	(80.0%)	6	(20.0%)
41–50	18	(5.3%)	18	(94.7%)
51–60	5	(71.4%)	2	(28.6%)
61–70	4	(66.7%)	2	(33.3%)
71–80	0	(0.0%)	0	(0.0%)
Gender					0.036	(1)	0.850
Male	25	(78.1%)	7	(21.9%)
Female	65	(76.5%)	20	(23.5%)
Ethnicity					2.576^b	(3)	0.462
Malay	66	(75.9%)	21	(24.1%)
Chinese	12	(85.7%)	2	(14.3%)
Indian	10	(83.3%)	2	(16.7%)
Others	2	(50.0%)	2	(50.0%)
Education level					3.698^b	(2)	0.157
Graduate/ Post graduate degree	73	(80.2%)	18	(19.8%)
High school/Diploma	10	(58.8%)	7	(41.2%)
Less than high school	7	(77.8%)	2	(22.2%)
Comorbidities							1.000^c
Yes	12	(80.0%)	3	(20.0%)
No	78	(76.5%)	24	(23.5%)
Employment status					1.192	(1)	0.275
Employed	54	(80.6%)	13	(19.4%)
Unemployed	36	(72.0%)	14	(28.0%)
Previous COVID-19 infection							0.761^c
Yes	15	(83.3%)	3	(16.7%)
No	75	(75.8%)	24	(24.2%)

^a Independent T-test is performed.

^b Pearson Chi Square test is performed.

^c Fischer exact test is performed.

Table 6. The association between adverse effects post Oxford-AstraZeneca (ChAdOx1-®[recombinant]) vaccination and demographic profile (n = 127).

Demographic profile	Adverse effects				X^2	(df)	Mann-Whitney U	P value
	Yes		No
	n	(%)	n	(%)
Age							800	0.945^a
18–30	50	(86.2%)	8	(13.8%)
31–40	25	(96.2%)	1	(3.8%)
41–50	25	(100.0%)	0	(0.0%)
51–60	5	(71.4%)	2	(28.6%)
61–70	8	(72.7%)	3	(27.3%)
71–80	0	(0.0%)	0	(0.0%)
Gender								0.467^b
Male	23	(95.8%)	1	(4.2%)
Female	90	(87.4%)	13	(12.6%)
Ethnicity					1.570^c	(3)		0.666
Malay	99	(89.2%)	12	(10.8%)
Chinese	4	(80.0%)	1	(20.0%)
Indian	6	(100.0%)	0	(0.0%)
Others	4	(89.0%)	1	(11.0%)
Education level					1.301^c	(2)		0.522
Graduate/ Post graduate degree	95	(89.6%)	11	(10.4%)
High school/ Diploma	14	(82.4%)	3	(17.6%)
Less than high school	4	(100.0%)	0	(0.0%)
Comorbidities								0.317^b
Yes	25	(83.3%)	5	(16.7%)
No	88	(90.7%)	9	(9.3%)
Employment status					2.982	(1)		0.084
Employed	75	(92.6%)	6	(7.4%)
Unemployed	38	(82.6%)	8	(17.4%)
Previous COVID-19 infection								0.609^b
Yes	11	(100.0%)	0	(0.0%)
No	102	(87.9%)	14	(12.1%)

^a Mann-Whitney U test is performed.

^b Fischer exact test is performed.

^c Pearson Chi Square test is performed.

Table 7. The association between adverse effects post mixed COVID-19 vaccination and demographic profile (n = 273).

Demographic profile	Adverse effects				X^2	(df)	P value
	Yes		No
	n	(%)	n	(%)
Age					0.848^a	(271)	0.397
18–30	88	(94.6%)	5	(5.4%)
31–40	63	(95.5%)	3	(4.5%)
41–50	47	(90.4%)	5	(9.6%)
51–60	37	(90.2%)	4	(9.8%)
61–70	16	(88.9%)	2	(11.1%)
71–80	3	(100.0%)	0	(0.0%)
Gender							0.269^b
Male	61	(89.7%)	7	(10.3%)
Female	193	(94.1%)	12	(5.9%)
Ethnicity					4.988^c	(3)	0.173
Malay	212	(94.6%)	12	(5.4%)
Chinese	12	(85.7%)	2	(14.3%)
Indian	19	(86.4%)	3	(13.6%)
Others	11	(84.6%)	2	(15.4%)
Education level					1.382^c	(2)	0.501
Graduate/ Post graduate degree	208	(93.7%)	14	(6.3%)
High school/ Diploma	34	(91.9%)	3	(8.1%)
Less than high school	12	(85.7%)	2	(14.3%)
Comorbidities					0.069	(1)	0.792
Yes	73	(92.4%)	6	(7.6%)
No	181	(93.3%)	13	(6.7%)
Employment status					0.911	(1)	0.340
Employed	174	(94.1%)	11	(5.9%)
Unemployed	80	(90.9%)	8	(9.1%)
Previous COVID-19 infection							0.116^b
Yes	24	(85.7%)	4	(14.3%)
No	230	(93.9%)	15	(6.1%)
Types of mixed vaccination					17.898^c	(3)	<0.001
Oxford-AstraZeneca (ChAdOx1-®[recombinant]) + Sinovac (CoronaVac®)	5	(100.0%)	0	(0.0%)
CanSino + Pfizer-BioNTech (Comirnaty ®)	0	(0.0%)	1	(100.0%)
Sinovac (CoronaVac®) + Pfizer-BioNTech (Comirnaty ®)	180	(91.4%)	17	(8.6%)
Oxford-AstraZeneca (ChAdOx1-®[recombinant]) + Pfizer-BioNTech (Comirnaty ®)	69	(98.6%)	1	(1.4%)

^a Independent T-test is performed.

^b Fischer Exact test is performed.

^c Pearson Chi Square test is performed.

Table 8. Association of adverse effects with types of COVID-19 vaccine based on vaccine status.

Adverse effects	COVID-19 vaccine status				X^2	(df)	P value
	Single vaccine^a		Mixed vaccines^b
	n	(%)	n	(%)
Overall adverse effects	560	(89.2%)	254	(93.0%)	3.264	(1)	0.071
Local adverse effects	523	(83.3%)	245	(89.7%)	6.318	(1)	0.012
Systemic adverse effects	517	(82.3%)	236	(86.4%)	2.355	(1)	0.125
Adverse effects after 1st dose	560	(89.2%)	254	(93.0%)	3.264	(1)	0.071
Adverse effects after 2nd dose	529	(84.2%)	187	(68.5%)	28.882	(1)	<0.001
Adverse effects after 3rd dose	192	(30.6%)	180	(65.9%)	98.151	(1)	<0.001
Local adverse effects after 1st dose	517	(82.3%)	245	(89.7%)	8.027	(1)	0.005
Local adverse effects after 2nd dose	474	(75.5%)	154	(56.4%)	32.757	(1)	<0.001
Local adverse effects after 3rd dose	178	(28.3%)	146	(53.5%)	52.205	(1)	<0.001
Systemic adverse effects after 1st dose	517	(82.3%)	236	(86.4%)	2.355	(1)	0.125
Systemic adverse effects after 2nd dose	440	(70.1%)	151	(55.3%)	18.349	(1)	<0.001
Systemic adverse effects after 3rd dose	159	(25.3%)	138	(50.5%)	54.818	(1)	<0.001

^a n =  628.

^b n =  273.

Table 9. Association of types of adverse effects with types of COVID-19 vaccine based on vaccine status.

Side effects	COVID-19 vaccine status				X^2	(df)	P value
	Single vaccine^a		Mixed vaccines^b
	n	(%)	n	(%)
Pain/ Soreness at injection site					21.337	(1)	<0.001
Yes	467	(74.4%)	161	(59.0%)
No	161	(25.6%)	112	(41.0%)
Swelling at injection site					6.581	(1)	0.010
Yes	511	(81.4%)	241	(88.3%)
No	117	(18.6%)	32	(11.7%)
Redness at injection site					0.556	(1)	0.456
Yes	257	(40.9%)	119	(43.6%)
No	371	(59.1%)	154	(56.4%)
Itchiness at injection site					2.555	(1)	0.110
Yes	199	(31.7%)	72	(26.4%)
No	429	(68.3%)	201	(73.6%)
Fatigue/Tiredness					1.713	(1)	0.191
Yes	388	(61.8%)	156	(57.1%)
No	240	(38.2%)	117	(42.9%)
Headache					0.559	(1)	0.455
Yes	440	(70.1%)	198	(72.5%)
No	188	(29.9%)	75	(27.5%)
Nausea					1.231	(1)	0.267
Yes	306	(48.7%)	144	(52.7%)
No	322	(51.3%)	129	(47.3%)
Vomiting					0.626	(1)	0.429
Yes	127	(20.2%)	49	(17.9%)
No	501	(79.8%)	224	(82.1%)
Muscle pain					24.222	(1)	<0.001
Yes	292	(46.5%)	79	(28.9%)
No	336	(53.5%)	194	(71.1%)
Muscle weakness					0.299	(1)	0.584
Yes	365	(58.1%)	164	(60.1%)
No	263	(41.9%)	109	(39.9%)
Chills and shivering					5.312	(1)	0.021
Yes	296	(47.1%)	106	(38.8%)
No	332	(52.9%)	167	(61.2%)
Joint pain					7.355	(1)	0.007
Yes	277	(44.1%)	94	(34.4%)
No	351	(55.9%)	179	(65.6%)
Fever					0.422	(1)	0.516
Yes	300	(47.8%)	124	(45.4%)
No	328	(52.2%)	149	(54.6%)
Skin rash					0.285	(1)	0.593
Yes	303	(48.2%)	137	(50.2%)
No	325	(51.8%)	136	(49.8%)
Insomnia					3.209	(1)	0.073
Yes	76	(12.1%)	22	(8.1%)
No	552	(87.9%)	251	(91.9%)
Swollen lymph nodes					0.921	(1)	0.337
Yes	86	(13.7%)	31	(11.4%)
No	542	(86.3%)	242	(88.6%)
Malaise					10.193	(1)	0.001
Yes	264	(42.0%)	84	(30.8%)
No	364	(58.0%)	189	(69.2%)
Diarrhea					1.958	(1)	0.162
Yes	324	(51.6%)	127	(46.5%)
No	304	(48.4%)	146	(53.5%)
Cough					1.175	(1)	0.278
Yes	47	(7.5%)	15	(5.5%)
No	581	(92.5%)	258	(94.5%)
Dizziness					0.914	(1)	0.339
Yes	147	(23.4%)	56	(20.5%)
No	481	(76.6%)	217	(79.5%)
Constipation					1.073	(1)	0.300
Yes	192	(30.6%)	93	(34.1%)
No	436	(69.4%)	180	(65.9%)
Sore throat					0.592	(1)	0.442
Yes	38	(6.1%)	13	(4.8%)
No	590	(93.9%)	260	(95.2%)
Runny nose					2.180	(1)	0.140
Yes	44	(7.0%)	27	(9.9%)
No	584	(93.0%)	246	(90.1%)

^a n =  628.

^b n =  273.

Table 10. Association of number of adverse effects reported with types of COVID-19 vaccine based on age group.

Age group	Types of COVID-19 vaccine	Number of side effects reported				Adverse effects		X^2	(df)	P value
		≤5		>5
		n	(%)	n	(%)	n	(%)
18–30 years	Pfizer-BioNTech (Comirnaty ®)	27	(7.1%)	100	(26.2%)	127	(33.3%)	44.742	(8)	<0.001
	Sinovac (CoronaVac®)	16	(13.7%)	23	(19.7%)	39	(33.3%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	4	(3.1%)	46	(36.2%)	50	(39.4%)
	Mixed COVID-19 vaccine	12	(4.4%)	76	(27.8%)	88	(32.2%)
31–40 years	Pfizer-BioNTech (Comirnaty ®)	26	(6.8%)	97	(25.5%)	123	(32.3%)	20.285	(8)	0.009
	Sinovac (CoronaVac®)	10	(8.5%)	14	(12.0%)	24	(20.5%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	3	(2.4%)	22	(17.3%)	25	(19.7%)
	Mixed COVID-19 vaccine	15	(5.5%)	48	(17.6%)	63	(23.1%)
41–50 years	Pfizer-BioNTech (Comirnaty ®)	3	(0.8%)	60	(15.7%)	63	(16.5%)	24.497	(6)	<0.001
	Sinovac (CoronaVac®)	5	(4.3%)	13	(11.1%)	18	(15.4%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	3	(2.4%)	22	(17.3%)	25	(19.7%)
	Mixed COVID-19 vaccine	18	(6.6%)	29	(10.6%)	47	(17.2%)
51–60 years	Pfizer-BioNTech (Comirnaty ®)	2	(0.5%)	18	(4.7%)	20	(5.2%)	12.851	(6)	0.045
	Sinovac (CoronaVac®)	2	(1.7%)	3	(2.6%)	5	(4.3%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	0	(0.0%)	5	(3.9%)	5	(3.9%)
	Mixed COVID-19 vaccine	16	(5.9%)	21	(7.7%)	37	(13.6%)
61–70 years	Pfizer-BioNTech (Comirnaty ®)	6	(1.6%)	15	(3.9%)	21	(5.5%)	9.454	(6)	0.150
	Sinovac (CoronaVac®)	0	(0.0%)	4	(3.4%)	4	(3.4%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	4	(3.1%)	4	(3.1%)	8	(6.3%)
	Mixed COVID-19 vaccine	8	(2.9%)	8	(2.9%)	16	(5.9%)
71–80 years	Pfizer-BioNTech (Comirnaty ®)	0	(0.0%)	1	(0.3%)	1	(0.3%)	1.333	(1)	0.248
	Sinovac (CoronaVac®)	0	(0.0%)	0	(0.0%)	0	(0.0%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	0	(0.0%)	0	(0.0%)	0	(0.0%)
	Mixed COVID-19 vaccine	2	(0.7%)	1	(0.4%)	3	(1.1%)

Table 11. Association of treatment for post COVID-19 vaccination adverse effects with types of COVID-19 vaccine based on age group.

Age group	Types of COVID-19 vaccine	Treatment for adverse effects				X^2	(df)	P value
		No		Yes
		n	(%)	n	(%)
18–30 years	Pfizer-BioNTech (Comirnaty ®)	44	(34.6%)	83	(65.4%)	41.200	(4)	<0.001
	Sinovac (CoronaVac®)	28	(71.8%)	11	(28.2%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	10	(20.0%)	40	(80.0%)
	Mixed COVID-19 vaccine	26	(29.5%)	62	(70.5%)
31–40 years	Pfizer-BioNTech (Comirnaty ®)	46	(37.4%)	77	(62.6%)	11.305	(4)	0.023
	Sinovac (CoronaVac®)	14	(58.3%)	10	(41.7%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	6	(24.0%)	19	(76.0%)
	Mixed COVID-19 vaccine	26	(41.3%)	37	(58.7%)
41–50 years	Pfizer-BioNTech (Comirnaty ®)	14	(22.2%)	49	(77.8%)	8.876	(3)	0.031
	Sinovac (CoronaVac®)	10	(55.6%)	8	(44.4%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	9	(36.0%)	16	(64.0%)
	Mixed COVID-19 vaccine	23	(48.9%)	24	(51.1%)
51–60 years	Pfizer-BioNTech (Comirnaty ®)	9	(45.0%)	11	(55.0%)	1.338	(3)	0.720
	Sinovac (CoronaVac®)	3	(60.0%)	2	(40.0%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	2	(40.0%)	3	(60.0%)
	Mixed COVID-19 vaccine	16	(43.2%)	21	(56.8%)
61–70 years	Pfizer-BioNTech (Comirnaty ®)	8	(38.1%)	13	(61.9%)	1.690	(3)	0.639
	Sinovac (CoronaVac®)	2	(50.0%)	2	(50.0%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	2	(25.0%)	6	(75.0%)
	Mixed COVID-19 vaccine	8	(50.0%)	8	(50.0%)
71–80 years	Pfizer-BioNTech (Comirnaty ®)	1	(100.0%)	0	(0.0%)			1.000^a
	Sinovac (CoronaVac®)	0	(0.0%)	0	(0.0%)
	Oxford-AstraZeneca (ChAdOx1-®[recombinant])	0	(0.0%)	0	(0.0%)
	Mixed COVID-19 vaccine	2	(66.7%)	1	(33.3%)

^a Fischer Exact test is performed.