Table 3.

Number of preventable^a and non-preventable^b reported cases of measles among U.S. residents, by age, travel history, and measles vaccination status, United States, 2009–2014 (n=1171)

	International travel		No international travel		Total
Age group	Vaccinated	Not vaccinated or unknown vaccination status	Vaccinated	Not vaccinated or unknown vaccination status
<6 months	0	1	0	21	22
6–11 months	0	28a	1	57	86
12–15 months	0	27a	4	34	65
16 months– 4 years	4	15a	20	127a	166
5–9 years	3	2a	4	120a	129
10–19 years	1	20a	14	208a	243
20–29 years	8	32a	21	140a	201
30–39 years	6	13a	16	87d	122
≥40 years	2	32c	16	87e	137
Total case-patients	24	170	96	881	1171f
Total preventable	0	159	0	758	917
Total non-preventable	24	11	96	123	254

^aCase-patients with preventable measles were case-patients for whom vaccination was recommended by the Advisory Committee on Immunization Practices but who had not received ≥1 dose of measles-containing vaccine.

^bCases were defined as non-preventable if they occurred among US-resident case-patients who had received ≥1 dose of measles containing vaccine, were vaccinated as recommended if traveling internationally, or were not vaccinated but had other evidence of measles immunity (i.e., were born before 1957 and therefore were presumed to be immune from natural disease in childhood, had laboratory evidence of immunity, or laboratory confirmation of disease) or for whom vaccination is not recommended.

^cOf the 32 case-patients ≥40 years who were unvaccinated or had unknown vaccination status who traveled internationally, 22 were preventable. All 10 non-preventable case-patients were persons born before 1957 (measles-containing vaccine is not recommended for people in this age group, because they are presumed to be immune from natural disease in childhood).

^dOf the 87 case-patients aged 30–39 years who were unvaccinated or had unknown vaccination status who did not travel internationally, 86 were preventable. The non-preventable case-patient had a documented positive measles titer.

^eOf the 87 case-patients aged ≥40 years who were unvaccinated or had unknown vaccination status who did not travel internationally, 77 were preventable. Of the 10 non-preventable case-patients, 8 occurred in persons born before 1957 (measles-containing vaccine is not recommended for people in this age group, because they are presumed to be immune from natural disease in childhood) and 2 case-patients had documented positive measles titers.

^fMissing age data on 2 case-patients.