Rotavirus vaccine was introduced in El Salvador in 2006 and is recommended to be 
given concomitantly with DTP-HepB-Haemophilus influenzae type b (pentavalent) 
vaccine at ages 2 months (upper age limit 15 weeks) and 4 months (upper age 
limit 8 months) of age. However, rotavirus vaccination coverage continues to lag 
behind that of pentavalent vaccine, even in years when national rotavirus 
vaccine stock-outs have not occurred. We analyzed factors associated with 
receipt of oral rotavirus vaccine among children who received at least 2 doses 
of pentavalent vaccine in a stratified cluster survey of children aged 24-59 
months conducted in El Salvador in 2011. Vaccine doses included were documented 
on vaccination cards (94.4%) or in health facility records (5.6%). Logistic 
regression and survival analysis were used to assess factors associated with 
vaccination status and age at vaccination. Receipt of pentavalent vaccine by age 
15 weeks was associated with rotavirus vaccination (OR: 5.1; 95% CI 2.7, 9.4), 
and receipt of the second pentavalent dose by age 32 weeks was associated with 
receipt of two rotavirus vaccine doses (OR: 5.0; 95% CI 2.1-12.3). Timely 
coverage with the first pentavalent vaccine dose was 88.2% in the 2007 cohort 
and 91.1% in the 2008 cohort (p=0.04). Children born in 2009, when a four-month 
national rotavirus vaccine stock-out occurred, had an older median age of 
receipt of rotavirus vaccine and were less likely to receive rotavirus on the 
same date as the same dose of pentavalent vaccine than children born in 2007 and 
2008. Upper age limit recommendations for rotavirus vaccine administration 
contributed to suboptimal vaccination coverage. Survey data suggest that late 
rotavirus vaccination and co-administration with later doses of pentavalent 
vaccine among children born in 2009 helped increase rotavirus vaccine coverage 
following shortages.