Acceptability questionnaire consists of 9 question (Q) to assess ease, time, overall satisfaction of study drug. Rated on 5-point scale for Q1-Q5 and Q7-Q9; Q6 was not rated and asked for name of previous PEP administered. Q1=overall ease of administration (1=not at all easy,2=somewhat,3=easy,4=very,5=extremely); Q2=time of administration (1=very short[<2 min],2=short[2-5 min],3=moderate[5-15 min],4=long[15-25 min],5=very long[>25 min]);Q3=overall infant acceptance(1=very easily,2=easily,3=same,4=with difficulty,5=with great difficulty);Q4=clear/complete instructions(1=not clear,2=somewhat,3=clear,4=very,5=extremely);Q5=overall satisfaction with dosing method (1=not satisfied,2=somewhat,3=satisfied,4=very,5=extremely);Q7=comparative ease of administration (1=much worse,2=worse,3=same,4=better,5=much better);Q8=comparative infant acceptance (1=much more difficult,2=more,3=same,4=easier,5=much easier);Q9=comparative overall satisfaction (1=much less,2=less,3=same,4=more,5=much more).