ACIP Evidence to Recommendations Framework

Background: Despite successful implementation of the United States’ routine hepatitis A vaccination recommendation for children aged 

12–23 months, there remains a small gap to close among adolescents who have not received hepatitis A vaccine and are thus missing 

long-term and potential lifetime protection from hepatitis A. 

Decreased hepatitis A incidence in the United States and reduced exposure to hepatitis A virus (HAV) have resulted in decreased antiHAV seroprevalence among adults, and an increased proportion of susceptible adults, including younger adults (i.e., aged 20–29 years). 

Vaccinating adolescents will lead to increased protection among adults—particularly young adults—more quickly than waiting for the 

routinely vaccinated cohort of children to reach adulthood. It also will protect those with undisclosed risk factors (e.g., drug use, men who 

have sex with men [MSM]) more consistently and earlier in life.

In 2006, the Advisory Committee on Immunization Practices (ACIP) recommended routine hepatitis A vaccination for all children aged 12–

23 months. Children who are not vaccinated by age 2 years can be vaccinated at subsequent health care visits, and catch-up vaccination of 

unvaccinated children aged 2–18 years can be considered based on shared clinical decision-making. Catch-up vaccination ensures that the 

percentage of children/adolescents who miss vaccination as scheduled or who were born outside of the routinely vaccinated cohort (i.e., 

born prior to 2006) are protected and is a way to increase herd immunity.

In 2017, national hepatitis A vaccination coverage among adolescents aged 13–17 years was 77.2% for 1 dose and 68.4% for ≥2 doses, 

compared to 36.2% and 25.3% for 1 and ≥2 doses, respectively, in 2008. This indicates substantial catch-up implementation and 

acceptance despite a recommendation based on clinical decision-making (1, 2). 

The vaccines containing HAV antigen that are currently licensed in the United States for children are the inactivated, single-antigen 

vaccines HAVRIX® (manufactured by GlaxoSmithKline, Rixensart, Belgium) and VAQTA® (manufactured by Merck & Co., Inc., 

Whitehouse Station, New Jersey). 

Additional background information supporting the ACIP recommendations on the use of hepatitis A vaccines can be found in the relevant 

publication of the recommendations referenced on the ACIP website. https://www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/hepa.html

Question: Should hepatitis A catch-up vaccination be recommended for children age 2–18 years?

Population: Children aged 2–18 years

Intervention: Hepatitis A vaccination (2-dose schedule) 

Comparison(s): Hepatitis A catch-up vaccination based on individual clinical decision-making 

Outcome: 

• Hepatitis A infection

https://www.cdc.gov/vaccines/acip/recs/grade/hep-a-catch-up-etr-h.pdf 7/17/2020
ACIP Evidence to Recommendations Framework

CRITERIA WORK GROUP JUDGMENTS EVIDENCE ADDITIONAL INFORMATION

PROBLEM

Is the problem 

of public 

health 

importance?

No Probably

no

Uncertain Probably

yes

Yes Varies

X

Incidence: The rate of reported acute 

hepatitis A cases in 2017 was 1.0 

cases/100,000 population (3). 

• However, the rate of reported acute

hepatitis A cases for young adults

aged 20–30 years was 1.45

cases/100,000 population (0.87 in

2016); and 2.07 cases/100,000

population for persons aged 30–39

(3).

• The 30–39 years age group has the

highest incidence, which is more than

double the 2016 rate for this age

group (0.92 cases per 100,000 in

2016) (4).

HAV outbreaks: Since widespread personto-person outbreaks of hepatitis A across the 

United States were first identified in 2016, 23 

states have publicly reported the following as 

of June 14, 2019 (5): 

• Cases: 20,133

• Hospitalizations: 11,595 (58%)

• Deaths: 191

• Among states with publicly available

case information by age group, the

median age of HAV cases is in the 30s,

with a substantial percentage of cases

among individuals in their 20s and

40s.

Hepatitis A vaccination coverage: In 2017, 

national hepatitis A vaccination coverage was 

77.2% for 1 dose among adolescents aged 

13–17 years and 68.4% for ≥2 doses (1).

Vaccinating teens protects 

those who may be at risk for 

HAV infection (e.g., persons 

who use drugs, persons 

experiencing homelessness, 

travelers) at present and in 

the future.
ACIP Evidence to Recommendations Framework

Among adolescents aged 13–17 years living in 

states where routine vaccination at 12–23 

months was first recommended in 2006, 

coverage is only slightly lower than the total 

cohort, at 71% for 1 dose and 61% for ≥2 doses.

BENEFITS & HARMS 

How 

substantial 

are the 

desirable 

anticipated 

effects?

Minimal Small Moderate Large Don’t 

know

Varies

X

HAVRIX and VAQTA are highly immunogenic 

when administered to children and 

adolescents according to multiple schedules. • 97%–100% of persons aged 2–18 

years had protective levels of 

antibody 1 month after receiving the 

first dose, and 100% had protective 

levels 1 month after the second dose, 

with high geometric mean 

concentrations (6–14).

Due to demonstrated long-term protection 

from the vaccines, there is little concern that 

childhood vaccination will result in risk later 

in life due to waning immunity.

• Antibody to HAV (anti-HAV) has been 

shown to persist for at least 22 years 

in adults administered inactivated 

vaccine as children (aged 3–6 years)

(15, 16).

• Mathematical modelling based on 

persons vaccinated as adults predicted 

that seropositive anti-HAV levels would 

persist in ≥95% of vaccinees at year 30 

and ≥90% at year 40 (17). 

• Vaccine-induced cellular immunity has 

been shown to promote HAV-specific 

Catch-up vaccination 

ensures children and 

adolescents who miss 

vaccination as scheduled or 

who were born outside of 

the routinely vaccinated 

cohort are protected and 

increases herd immunity.

In addition, since 

implementation of riskbased vaccination in adults 

has been poor, catch-up 

vaccination will more rapidly 

increase the proportion of 

adults with risk factors who 

are protected. 
ACIP Evidence to Recommendations Framework

cellular immunity similar to that 

induced by natural infection (18).

CRITERIA WORK GROUP JUDGMENTS RESEARCH EVIDENCE ADDITIONAL INFORMATION

How 

substantial 

are the 

undesirable 

anticipated 

effects?

Minimal Small Moderate Large Don’t 

know

Varie

s

X

More than 20 years of safety monitoring have 

shown no safety concerns. 

No unusual or unexpected safety patterns were 

observed in the Vaccine Adverse Event 

Reporting System for any hepatitis A vaccines

(1).

Rates of adverse events following TWINRIX® 

vaccination were similar to those seen with 

separately administered hepatitis A and 

hepatitis B vaccines (19). (TWINRIX® is 

approved for use in persons 18 years of age or 

older.)

Do the 

desirable 

effects 

outweigh the 

undesirable 

effects?

Favors 

intervention

Favors 

comparison

Favors 

both

Favors 

neither

Unclear

X

Hepatitis A vaccination affords long-term 

protection against HAV infection. 

• Disease severity increases as persons 

age.

• More than 20 years of safety monitoring 

have shown no safety concerns. 

• Earlier hepatitis A vaccination among 

healthy children/adolescents provides 

protection against HAV infection before 

persons develop increased risk for HAV 

infection or HAV-associated 

complications.

What is the 

overall 

certainty of 

this evidence 

for the critical 

outcomes?

Effectiveness of the intervention

No

included

studies

4 

Very low

3 

Low

2

Moderate

1

High

X

Safety of the intervention

No

included

studies

4

Very low

3

Low

2

Moderate

1

High

X

GRADE was not used to evaluate the evidence. 

• Hepatitis A vaccine has been 

recommended for administration to 

children since 1996. 

• Hepatitis A vaccine has been 

recommended for catch-up vaccination 

based on clinical decision-making since 

2006. 

• The efficacy and safety of Hepatitis A 

vaccines has been evaluated and well 

documented. 
ACIP Evidence to Recommendations Framework • There are no known safety concerns 

with hepatitis A vaccines. 

VALUES

Does the 

target 

population 

feel that the 

desirable 

effects are 

large relative 

to undesirable 

effects?

No Probably

no

Uncertain Probably

yes

Yes Varies

X

In 2017, national hepatitis A vaccination 

coverage among adolescents aged 13–17 years 

was 77.2% for 1 dose and 68.4% for ≥2 doses 

compared to 36.2% and 25.3% for 1 and ≥2 

doses, respectively, in 2008 (1, 2). 

• This indicates substantial catch-up 

vaccination implementation and 

acceptance despite a recommendation 

based on clinical decision-making. 

• Specific studies of demand among older 

children for hepatitis A vaccine have not 

been done. However, almost 70% of 

teens have already initiated the vaccine 

series even though catch-up vaccination 

is not routinely recommended,

suggesting parental acceptance or 

demand for hepatitis A vaccination.

Compared to other vaccines 

with a routine catch-up 

schedule, hepatitis A

adolescent 2-dose coverage 

is comparable (e.g.,

quadrivalent meningococcal 

conjugate vaccine) or greater 

(e.g., human papillomavirus 

vaccine), providing evidence 

of acceptability by the target 

population (1).

CRITERIA WORK GROUP JUDGMENTS RESEARCH EVIDENCE ADDITIONAL INFORMATION

Is there 

important 

uncertainty 

about or 

variability in 

how much 

people value 

the main 

outcomes?

Important uncertainty or variability

Possibly important uncertainty or variability

Probably no important uncertainty or 

variability

X

No important uncertainty or variability

No known undesirable outcomes

The high coverage rate, despite this 

recommendation being based on clinical 

decision-making, provides strong and consistent 

evidence that most parents believe that it is 

important.
ACIP Evidence to Recommendations Framework

ACCEPTABILITY

Is the 

intervention 

acceptable to 

key 

stakeholders?

No Probably

no

Uncertain Probably

yes

Yes Varies

X

CDC currently does not have a routine catch-up 

recommendation for children aged 2–18 years, 

yet 21 states have introduced mandates for 

daycare, daycare plus school, or school alone. 

This represents an increase in states with 

mandates from 28% in 2011 to 40% in 2018

(20).

• As of October 2018, 12 states have a 

daycare and school mandate; 8 states 

plus part of Arizona have a daycare-only 

mandate; 1 state has a school-only 

mandate (Indiana). 

Children who were 1 year 

of age when the routine 

recommendation was first 

published in 2006 were 

~12–13 years old in 2017 

when these data were 

collected; nearly all of the 

cohort of children 13–17 

assessed in 2017 were not 

subject to the routine 

recommendation for 

children 12–23 months of 

age. High overall coverage 

in this age group 

demonstrates that catchup vaccination is 

occurring.

As noted above, the hepatitis 

A adolescent 2-dose 

coverage is comparable or 

greater than other vaccines 

with a routine catch-up 

schedule, which provides 

evidence of acceptability by 

key stakeholder populations.

RESOURCE USE

Is the 

intervention a 

reasonable 

and efficient 

allocation of 

resources?

No Probably

no

Uncertain Probably

yes

Yes

X

Cost analysis: After universal childhood 

recommendation implementation, a costeffectiveness model used to assess nationwide 

routine hepatitis A vaccination was adapted to 

assess the cost-effectiveness of catch-up 

hepatitis A vaccination among unvaccinated and 

partially vaccinated children compared with 

unvaccinated children (21). 

• Over the cohort’s lifetime, catch-up 

vaccination would reduce the total 

number of infections relative to baseline 

by 741. 

• Catch-up vaccination would increase net 

cost by $2.38 per person. 

Other studies: To assess the 

population-level impact and 

cost-effectiveness of US 

hepatitis vaccination 

programs, an age-structured 

population model of 

hepatitis A transmission 

dynamics was developed to 

evaluate two policies of 

administering a 2-dose 

hepatitis A vaccine to 

children aged 12 to 18 

months (22). 

• The model predicted 

universal childhood 
ACIP Evidence to Recommendations Framework • Incremental cost of hepatitis A vaccine 

catch-up intervention at age 10 years, 

the midpoint of the ages modeled, was 

$452,239 per QALY gained. 

• Across age cohorts, cost effectiveness of 

catch-up vaccination is most favorable at 

age 12 years, resulting in an incremental 

cost-effectiveness ratio (ICER) of 

$189,000 per QALY gained. 

o The impact of vaccination on the 

ICER was most sensitive to the 

discount rate, followed by the 

rate of adult vaccination.

• The model assumed administration 

costs of hepatitis A vaccination were

split with other vaccines routinely 

administered at age 12 years, thus 

lowering the cost of vaccination. 

• Catch-up vaccination in adolescence is 

more effective when it is assumed to 

replace later vaccination as an adult. 

o Catch-up became more cost 

effective when targeting children 

in late adolescence, due to higher 

probability of symptomatic 

disease among older children, 

less discounting of future costs 

of disease, and less delay in 

averting adult vaccination costs. 

• Limitations: model output is based on 

hepatitis A incidence from 2008 to 2012 

and the cost-effectiveness conclusions 

are strongly tied to factors such as 

vaccine uptake and disease transmission 

patterns which may change over time, 

altering future cost. 

• The model also excluded herd immunity 

effects from vaccination.

Incremental costs of catch up now, given 

current rates of coverage among 13–17-yearhepatitis A

vaccination would

lead to significant 

reduction in hepatitis 

A mortality and 

morbidity. 

• Universal vaccination 

was cost saving 

compared with a 

regional vaccination 

policy. 

• The model predicts 

US incidence will fall 

to 27/100,000 by 

2020, compared to a 

CDC-reported 

incidence (adjusted 

for underreporting) 

of just 1.71/100,000. 

• This model 

overestimates 

incidence which 

limits applicability of 

inferences from 

these findings to 

catch-up policies.

• While this model 

provides a favorable 

cost-effectiveness 

estimate, limitations 

exist. 

Additional Considerations: 

Cost of outbreak response 

and hospitalization is 

substantial and would offset 

some of additional costs of 

catch-up vaccination. 

Based on 2017 hepatitis A

vaccination coverage rates:
ACIP Evidence to Recommendations Framework

olds, would be more favorable, because 

hepatitis A vaccination coverage rates are 

higher among vaccinated children who are aging 

into the adolescent cohort:

• 2008, 1 dose: 36.2%, ≥2-dose: 25.3%,

versus 2017, 1 dose: 77.2%, 2-dose 

68.5%. (1,2).

Achieving 80%–90% coverage among teens 

would require a much smaller number of 

additional vaccines given. In addition, HAV 

incidence overall is higher due to the ongoing 

multistate outbreaks (0.5 cases/100,000 

population in 2012 versus 1.0 case/100,000 

population in 2017) (1, 22).

• To achieve 80% 

hepatitis A vaccine 

series completion 

among adolescents, 

2,205,491 additional 

persons would need 

to be vaccinated with 

one dose and 

701,747 persons 

would need to be 

vaccinated with 2 

doses, at a cost of 

$59.3M (private) or 

$37M (CDC). 

• To achieve 90% 

hepatitis A vaccine 

series initiation 

among adolescents, 

3,207,987 persons 

would need to be 

vaccinated with 1 

dose, at a cost of 

$52.8M (private), 

$32.9M (CDC). 

Assumptions:

1) 2017 coverage rates apply 

to all children; however, in 

actuality, younger 

adolescents have higher 

coverage. 

2) 100% of 1-dose recipients 

complete series when 

calculating cost of 80% 

completion. 

3) Private sector covers 50% 

of these adolescents and CDC 

covers 50%.
ACIP Evidence to Recommendations Framework

FEASIBILITY

Is the 

intervention 

feasible to 

implement?

No Probably

no

Uncertain Probably

yes

Yes Varies

X

Of the 30 registries American Immunization 

Registry Association (AIRA) were able to query 

to test forecasting algorithms, 27 already 

routinely forecast hepatitis A vaccine for an 18-

year-old who has never been vaccinated. All 30 

algorithms forecast the second dose in any 18-

year-old who has had one dose. Essentially,

these algorithms are implemented as routine 

catch-up. Therefore, 27 of 30 registries would

not have to change to implement routine catchup. 

Findings from a 2014 survey (23) indicate:

• If ACIP made a recommendation for 

catch-up hepatitis A vaccination at 

health maintenance visits for all 

children 2 to 18 years of age, 96% of 

pediatricians and 79% of family 

physicians reported it would be very 

feasible to routinely assess hepatitis A

vaccination status and vaccinate 

children and adolescents who were not 

fully vaccinated.

o An additional 4% and 19%, 

respectively, indicated it would 

be moderately feasible. 

• The most common barriers to 

implementing a hepatitis A vaccine 

catchup recommendation included 

infrequent visits by adolescent patients 

(65%); parents’ lack of knowledge on 

the seriousness of HAV disease (39%); 

hepatitis A vaccination not being 

required for childcare or school entry 

(39%); difficulty obtaining 

immunization records to determine a 

patient’s hepatitis A vaccination status 

(35%); and parental concerns about 

giving too many vaccines at 1 visit 

(33%). 

Routine hepatitis A catch-up 

already exists in states that 

have school mandates (21 

states have introduced 

mandates for daycare, 

daycare plus school, or 

school alone.). In New York 

City, all children and 

adolescents not previously 

vaccinated should receive 

the two-dose hepatitis A 

vaccine series by their 19th 

birthday for long-term

protection (24).

There are opportunities to 

administer hepatitis A 

vaccine to adolescents

concurrently with vaccines 

protecting against other 

infections, such as human 

papillomavirus and 

meningococcal disease.
ACIP Evidence to Recommendations Framework • This study was performed 6 years ago 

and there is currently more education 

and awareness among providers and 

the public due to ongoing outbreaks, 

likely decreasing barriers to 

vaccination.

Balance of 

consequences

Undesirable 

consequences 

clearly outweigh

desirable 

consequences

in most settings

Undesirable 

consequences 

probably outweigh

desirable 

consequences

in most settings

The balance 

between 

desirable and 

undesirable 

consequences 

is closely balanced 

or uncertain

Desirable 

consequences 

probably outweigh 

undesirable 

consequences

in most settings

X

Desirable 

consequences 

clearly outweigh

undesirable 

consequences

in most settings

There is 

insufficient 

evidence to 

determine the 

balance of 

consequences

Is there sufficient information to move forward with a recommendation?

Yes X No

Policy Options for 

ACIP 

Consideration ACIP does not recommend the 

intervention

ACIP recommends the intervention for 

individuals based on clinical decisionmaking 

ACIP recommends the intervention

X

Recommendation 

(text)

Recommended for all unvaccinated children and adolescents aged 2–18 years. Children and adolescents who have 

not previously received hepatitis A vaccine should be vaccinated routinely at any age (i.e., children and adolescents 

are recommended for catch-up vaccination). 

Additional 

considerations

(optional)

Final deliberation and decision by the ACIP
ACIP Evidence to Recommendations Framework

Final ACIP 

recommendation

ACIP does not recommend the 

intervention

ACIP recommends the intervention 

for individuals based on shared 

clinical decision-making

ACIP recommends the intervention

X

ACIP 

considerations

i This Evidence to Recommendation table is based on the GRADE Evidence to Decision framework developed through the DECIDE project. Further 

information is available athttp://www.decide-collaboration.eu/evidence-decision-etd-framework

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ACIP Evidence to Recommendations Framework

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