Persons with moderate to severe immunocompromising conditions are at risk for severe
COVID-19, and their immune response to COVID-19 vaccination might not be as robust
as the response in persons who are not immunocompromised* (
1
). The Advisory Committee on Immunization Practices (ACIP) recommends that immunocompromised
persons aged ≥12 years complete a 3-dose primary mRNA COVID-19 vaccination series
followed by a first booster dose (dose 4) ≥3 months after dose 3 and a second booster
dose (dose 5) ≥4 months after dose 4.
†
To characterize the safety of first booster doses among immunocompromised persons
aged ≥12 years during January 12, 2022–March 28, 2022, CDC reviewed adverse events
and health impact assessments reported to v-safe and the Vaccine Adverse Event Reporting
System (VAERS) during the week after receipt of an mRNA COVID-19 first booster dose.
V-safe is a voluntary smartphone-based safety surveillance system for adverse events
after COVID-19 vaccination. VAERS is a passive surveillance system for all vaccine-associated
adverse events co-managed by CDC and the Food and Drug Administration (FDA). A fourth
mRNA dose reported to v-safe or VAERS during January 12, 2022–March 28, 2022, was
presumed to be an mRNA COVID-19 vaccine booster dose administered to an immunocompromised
person because no other population was authorized to receive a fourth dose during
that period (
2
,
3
). In the United States, during January 12, 2022–March 28, 2022, approximately 518,113
persons aged ≥12 years received a fourth dose. Among 4,015 v-safe registrants who
received a fourth dose, local and systemic reactions were less frequently reported
than were those following dose 3 of their primary series. VAERS received 145 reports
after fourth doses; 128 (88.3%) were nonserious and 17 (11.7%) were serious. Health
care providers, immunocompromised persons, and parents of immunocompromised children
should be aware that local and systemic reactions are expected after a first booster
mRNA COVID-19 vaccine dose, serious adverse events are rare, and safety findings were
consistent with those previously described among nonimmunocompromised persons (
4
,
5
).
V-safe is a voluntary, smartphone–based U.S. active safety surveillance system established
by CDC to monitor adverse events after COVID-19 vaccination (https://vsafe.cdc.gov/en/).
The v-safe platform allows registrants to report receipt of a COVID-19 booster dose;
new registrants enter information about all doses received. Coincident with authorization
for a booster dose in persons with moderate-to-severe immunocompromising conditions,
v-safe was updated to allow registrants to enter information about a fourth dose.
Registrants aged ≤15 years are enrolled by a parent or guardian. Health surveys sent
daily during the first week after administration of each dose include questions about
local injection site and systemic reactions and health impacts.
§
CDC’s v-safe call center contacts registrants who indicate that medical care was sought
after vaccination and encourages completion of a VAERS report, if indicated.
VAERS is a U.S. national passive safety surveillance system that monitors adverse
events after vaccination and is managed by CDC and FDA (
6
). VAERS accepts reports from health care providers, vaccine manufacturers, and the
general public.
¶
VAERS reports of hospitalization, prolongation of hospitalization, life-threatening
illness, permanent disability, congenital anomaly or birth defect, or death are classified
as serious.** VAERS staff members assign Medical Dictionary for Regulatory Activities
(MedDRA) preferred terms to the findings included in VAERS reports.
††
Serious reports to VAERS were reviewed by CDC and FDA physicians to form a consensus
clinical impression. For reports of death, death certificates and autopsy reports
are requested and reviewed by CDC physicians to form an impression about cause of
death. Reports of myocarditis and pericarditis, rare adverse events that have been
associated with mRNA-based COVID-19 vaccines, were identified by searching for selected
MedDRA preferred terms; CDC staff members attempted to collect information about clinical
course and determined whether the case definition was met.
§§
In v-safe, a fourth mRNA dose administered ≥3 months after dose 3 to a registrant
aged ≥12 years during January 12, 2022–March 28, 2022 (data processed April 17, 2022)
was presumed to be an mRNA COVID-19 vaccine booster dose administered to an immunocompromised
person; this cutoff date was chosen to reduce overlap with fourth doses administered
as a second booster to adults aged ≥50 years, which was recommended on March 29, 2022.
The odds of reporting an adverse reaction or health impact after a fourth versus a
third dose were compared using a multivariable generalized estimated equations model
that accounted for demographic variables, vaccine manufacturer, and repeated measures;
p-values <0.05 were considered statistically significant. VAERS adverse event reports
after a fourth dose among immunocompromised persons were described by seriousness
classification (serious versus nonserious), demographic characteristics, and MedDRA
preferred terms; a report of a fourth mRNA dose administered to a person aged ≥12
years during January 12, 2022–March 28, 2022 (data processed April 17, 2022) that
did not include MedDRA preferred terms for vaccine error was presumed to be an mRNA
COVID-19 vaccine booster dose administered to an immunocompromised person. SAS software
(version 9.4; SAS Institute) was used to conduct all analyses. These surveillance
activities were reviewed by CDC and conducted consistent with applicable federal law
and CDC policy.
¶¶
Review of v-safe Data
Overall, 4,015 v-safe registrants reported receiving a fourth dose during January
12, 2022–March 28, 2022, and were presumed to be immunocompromised persons receiving
a booster dose; 2,194 persons (54.6%) received mRNA-1273 (Moderna) vaccine and 1,821
(45.4%) BNT162b2 (Pfizer- BioNTech) vaccine. The median registrant age was 62 years
(range = 12–94 years); 2,489 (62.0%) were female. In the week after vaccination, local
injection site reactions and systemic reactions were reported by 1,605 (73.2%) and
1,470 (67.0%) Moderna vaccine recipients, respectively, and by 1,209 (66.4%) and 1,155
(63.4%) Pfizer-BioNTech vaccine recipients, respectively (Table 1). The most frequently
reported adverse reactions after dose 4 of either vaccine were injection site pain,
fatigue, headache, and myalgia. Local injection site reactions were less frequently
reported after dose 4 (70.1%) than after dose 3 (81.7%) (p<0.001); systemic reactions
also were less frequently reported after dose 4 (65.4%) than after dose 3 (76.8%)
(p<0.001) (Figure).
TABLE 1
Adverse reactions and health impacts reported* to v-safe after receipt of a presumed
mRNA COVID-19 vaccine booster
†
dose among immunocompromised persons (N = 4,015) — United States, January 12–March
28, 2022
Event
No. (%) reporting reaction or health impact after receipt of presumed booster dose
Moderna
(n = 2,194)
Pfizer-BioNTech
(n = 1,821)
Total
(N = 4,015)
Any local injection site reaction
1,605 (73.2)
1,209 (66.4)
2,814 (70.1)
Pain
1,512 (68.9)
1,157 (63.5)
2,669 (66.5)
Swelling
534 (24.3)
293 (16.1)
827 (20.6)
Redness
369 (16.8)
197 (10.8)
566 (14.1)
Itching
254 (11.6)
155 (8.5)
409 (10.2)
Any systemic reaction
1,470 (67.0)
1,155 (63.4)
2,625 (65.4)
Fatigue
1,164 (53.1)
884 (48.5)
2,048 (51.0)
Headache
863 (39.3)
676 (37.1)
1,539 (38.3)
Myalgia
833 (38.0)
659 (36.2)
1,492 (37.2)
Joint pain
544 (24.8)
425 (23.3)
969 (24.1)
Fever
504 (23.0)
371 (20.4)
875 (21.8)
Chills
501 (22.8)
325 (17.8)
826 (20.6)
Nausea
295 (13.4)
248 (13.6)
543 (13.5)
Diarrhea
152 (6.9)
141 (7.7)
293 (7.3)
Abdominal pain
126 (5.7)
127 (7.0)
253 (6.3)
Rash
40 (1.8)
35 (1.9)
75 (1.9)
Vomiting
21 (1.0)
29 (1.6)
50 (1.2)
Any health impact
608 (27.7)
455 (25.0)
1,063 (26.5)
Unable to perform normal daily activities
543 (24.7)
395 (21.7)
938 (23.4)
Unable to attend work or school
203 (9.3)
165 (9.1)
368 (9.2)
Received medical care
39 (1.8)
34 (1.9)
73 (1.8)
Telehealth
20 (0.9)
14 (0.8)
34 (0.8)
Clinic
8 (0.4)
11 (0.6)
19 (0.5)
Emergency visit
4 (0.2)
8 (0.4)
12 (0.3)
Hospitalization
1 (0.05)
1 (0.1)
2 (0.05)
* Percentage of registrants who reported a reaction or health impact ≥1 during days
0–7 after vaccination.
† A fourth mRNA dose ≥3 months after dose 3 administered to a participant aged ≥12
years was presumed to be an mRNA COVID-19 vaccine booster dose administered to an
immunocompromised person. Registrants aged ≤15 years must be enrolled by a parent
or guardian.
FIGURE
Adverse reactions and health impacts reported to v-safe* after receipt of COVID-19
vaccine doses among persons with presumed immunocompromised status
†
(N = 4,015), by vaccine dose — United States, January 12–March 28, 2022
* The odds of reporting an event following dose 3 and booster dose were compared for
registrants who completed at least one v-safe health check-in survey on days 0–7 after
booster dose and ≥1 other dose using a multivariable generalized estimating equations
model. This model adjusted for demographic variables and vaccine manufacturer and
accounted for repeated measures among doses reported by each registrant (“unable to
go to work or school” and “needed medical care” were not adjusted because of small
numbers). P-values <0.05 were considered statistically significant. All dose 3 and
booster dose differences were statistically significant (p<0.001) except “needed medical
care.”
† A fourth mRNA dose ≥3 months after dose 3 administered to a registrant aged ≥12
years was presumed to be an mRNA COVID-19 vaccine booster dose administered to an
immunocompromised person. Registrants aged ≤15 years must be enrolled by a parent
or guardian.
The figure comprises a bar chart showing adverse reactions and health impacts reported
to v-safe after receipt of COVID-19 vaccine doses among persons with presumed immunocompromise
status (N = 4,015), by vaccine dose in the United States during January 12 through
March 28, 2022.
In the week after dose 4 vaccination, 24.7% of Moderna vaccine recipients and 21.7%
of Pfizer-BioNTech vaccine recipients reported they were unable to complete their
daily activities, and approximately 9% of registrants reported they were unable to
attend work or school (Table 1). Fewer than 2% of registrants reported receipt of
medical care during the week after dose 4; most who did require care received it through
a telehealth appointment. Two registrants reported receiving care at a hospital during
the week after dose 4 vaccination. The v-safe call center contacted both these registrants;
one completed a VAERS report, and the other indicated the report was accidental or
unrelated to vaccination. Inability to work or attend school was less frequently reported
after dose 4 (9.2%) than after dose 3 (13.8%) (p<0.001); inability to perform daily
activities was less frequently reported after dose 4 (23.4%) than after dose 3 (34.5%)
(p<0.001) (Figure). Receipt of medical care was rarely and similarly reported after
receipt of either dose 4 (1.8%) or dose 3 (1.9%) (p = 0.70).
Review of VAERS Data
VAERS received 421 reports from persons who received a fourth dose during January
12–March 28, 2022; 276 (65.6%) of these reports listed a vaccine error. Among reports
noting a vaccine error, 225 (81.5%) indicated that no adverse health event occurred.
The remaining 145 (34.4%) reports were presumed to be for immunocompromised persons
who received a fourth dose. Among these, 105 (72.4%) reports were for events among
females, and the median age was 62 years. Most reports were for nonserious events
(128; 88.3%) (Table 2); the nonserious events most commonly reported included headache
(30; 23.4%), fatigue (26; 20.3%), and pain (22; 17.2%). One nonserious, preliminary
report of myocarditis remains under review. There were 17 (11.7%) reports of serious
adverse events. One report of death was received from a manufacturer regarding a patient
with pulmonary fibrosis who developed respiratory failure; at the time of publication,
no further information was available, and follow-up continues.
TABLE 2
Reports to the Vaccine Adverse Event Reporting System of nonserious and serious events
after receipt of a presumed mRNA COVID-19 vaccine booster* dose among immunocompromised
persons (N = 145) — United States, January 12–March 28, 2022
Reported event
No. (%) reporting
Nonserious VAERS reports
128 (100)
Symptom, sign, diagnostic result, or condition (MedDRA PT†)
Headache
30 (23.4)
Fatigue
26 (20.3)
Pain
22 (17.2)
Fever
18 (14.1)
Chills
15 (11.7)
Dizziness
12 (9.4)
Nausea
11 (8.6)
Rash
9 (7.0)
Conditional aggravated
8 (6.3)
Diarrhea
8 (6.3)
Injection site pain
8 (6.3)
Myalgia
8 (6.3)
Arthralgia
7 (5.5)
Erythema
7 (5.5)
Pain in extremity
7 (5.5)
Serious VAERS reports
§,¶
17 (100)
Clinical impression
Acute myocardial infarction
1 (5.9)
Anaphylactic reaction
1 (5.9)
Congestive heart failure
1 (5.9)
Chronic obstructive pulmonary disease exacerbation
1 (5.9)
Cerebrovascular accident
1 (5.9)
Diabetic ketoacidosis
1 (5.9)
Disseminated herpes zoster
1 (5.9)
Elevated liver enzymes, vomiting and diarrhea, fever, and arthralgia
1 (5.9)
Heart palpitations
1 (5.9)
Hyperglycemia; burning sensation in upper limb
1 (5.9)
No adverse event reported; vaccine received during mental health hospitalization
1 (5.9)
Pulmonary alveolar hemorrhage
1 (5.9)
Pulmonary embolism
1 (5.9)
Respiratory failure resulting in death in patient with pulmonary fibrosis
1 (5.9)
Respiratory syncytial virus pneumonia
1 (5.9)
Septic shock
1 (5.9)
Urosepsis
1 (5.9)
Abbreviations: MedDRA PT = Medical Dictionary for Regulatory Activities preferred
term; VAERS = Vaccine Adverse Event Reporting System.
* A fourth mRNA dose not administered in error among persons aged ≥12 years during
January 12, 2022–March 28, 2022, was presumed to be an mRNA COVID-19 vaccine booster
dose administered to an immunocompromised person. Reports indicating a vaccine error
(276) were omitted from this analysis in an attempt to only include fourth doses administered
as booster doses to immunocompromised persons.
† Signs and symptoms in VAERS reports are assigned MedDRA PTs by VAERS staff members.
Each VAERS report might be assigned one or more MedDRA PTs, which can include normal
diagnostic findings. A MedDRA PT does not indicate a medically confirmed diagnosis.
§ VAERS reports are classified as serious if any of the following are reported: hospitalization,
prolongation of hospitalization, life-threatening illness, permanent disability, congenital
anomaly or birth defect, or death.
¶ Serious reports to VAERS were reviewed by Food and Drug Administration and CDC physicians
to form a consensus clinical impression based on available data.
Discussion
This report presents safety findings from v-safe and VAERS after receipt of COVID-19
vaccine booster doses during a period when a fourth mRNA dose was recommended only
for persons with immunocompromising conditions. Reports to v-safe and VAERS after
mRNA booster vaccination among persons who received a fourth dose were similar to
previous reports that assessed safety data after dose 3 mRNA booster vaccination among
nonimmunocompromised persons (
4
,
5
).
Local and systemic reactions and health impacts were less frequently reported to v-safe
after receipt of dose 4 than after dose 3 of the primary series among persons with
presumed immunocompromise. Similarly, in previous analyses, among all v-safe registrants
aged ≥18 years who received a homologous mRNA booster, systemic reactions were less
frequent after dose 3 vaccination than after dose 2 (
5
). Among adolescents aged 12–17 years who received a homologous Pfizer-BioNTech third
dose, reactions were reported to v-safe with equal or slightly higher frequency after
receipt of that booster dose than after dose 2 (
4
).
Most reports to VAERS related to booster doses among persons with presumed immunocompromise
were nonserious; the most common adverse events reported were similar to those reported
by persons aged ≥18 years after an mRNA booster (
5
). Serious reports to VAERS among persons with presumed immunocompromise included
a range of adverse events; no unusual or unexpected reporting patterns were detected.
The findings in this report are subject to at least six limitations. First, v-safe
is a voluntary program; therefore, data might not be representative of the vaccinated
U.S. population. Second, it is possible that vaccinees who experience an adverse event
could be more likely to respond to v-safe surveys and the reported prevalence of adverse
events might overestimate the actual prevalence. Third, as a passive surveillance
system, VAERS is subject to reporting biases and underreporting, especially of nonserious
events (
6
). Fourth, v-safe does not collect information on immunocompromise, and VAERS does
not ask about immunocompromising health conditions; therefore, it is not possible
to confirm that vaccine recipients included in this analysis were immunocompromised.
Fifth, this report did not examine pattern of reporting by heterologous and homologous
vaccination. Finally, a report to v-safe or VAERS alone cannot be used to assess causality.
ACIP recommends that moderately or severely immunocompromised persons aged ≥12 years
receive a first booster dose ≥3 months after completion of a 3-dose primary COVID-19
vaccination series and a second booster dose ≥4 months after the first booster. Preliminary
safety findings for booster doses among persons with presumed immunocompromise are
similar to those among nonimmunocompromised persons; reactions are reported less frequently
after booster vaccination than after the last dose of a primary series. It is important
that health care providers, immunocompromised persons, and parents of immunocompromised
children be advised that local and systemic reactions are expected after a booster
dose, and that serious adverse events are rare. CDC and FDA will continue to monitor
vaccine safety and will provide updates as needed to guide COVID-19 vaccination recommendations.
Summary
What is already known about this topic?
Additional doses of COVID-19 vaccine are recommended for immunocompromised persons,
and 518,113 fourth doses were presumed administered to this population during January–March,
2022.
What is added by this report?
Among presumed immunocompromised persons aged ≥12 years, local and systemic reactions
were less frequently reported to v-safe after mRNA booster (dose 4) than after primary
series dose 3. Only 17 serious adverse events were reported to VAERS.
What are the implications for public health practice?
Serious adverse events after mRNA booster (dose 4) are rare. Immunocompromised persons
aged ≥12 years should receive a first booster ≥3 months after a 3-dose primary COVID-19
vaccination series and a second booster ≥4 months after the first booster.