Randomized trial of inactivated and live polio vaccine schedules in Guatemalan infants.
BACKGROUND
The immunogenicity of inactivated poliovirus vaccine (IPV) in developing countries is not well documented. This study compared the immune response to IPV with that to oral poliovirus vaccine (OPV) in Guatemalan infants.


METHODS
This was an open-label, randomized comparison of IPV only, OPV only, or IPV followed by OPV in Guatemalan public health clinics. Serum samples were tested for neutralizing antibodies, and stool samples were tested for Sabin strain polioviruses.


RESULTS
Seropositivity rates 2 months after 2 doses of IPV were 98%-100% for polio types 1, 2, and 3 and were 97.1%, 99.3%, and 92.1% for OPV-only recipients (P<.001 for the response to type 3). One month after the third dose, 100% of IPV-only recipients had protective antibodies against all 3 types, compared with 99%, 100%, and 97% against polio types 1, 2, and 3 respectively, among recipients of OPV only. Infants who received IPV only had higher geometric mean titers than infants who received OPV only. Maternal antibodies lowered the final antibody responses to IPV but did not prevent the development of protective levels of antibody. Of 191 stool samples from infants who received IPV only, 5 (2.6%) were positive for poliovirus vaccine strains.


CONCLUSIONS
IPV alone and IPV followed by OPV are safe and effective for Guatemalan infants.
Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
Edwin J
EJ
Asturias
Erica L
EL
Dueger
Saad B
SB
Omer
Arturo
A
Melville
Silvia V
SV
Nates
Majid
M
Laassri
Konstantin
K
Chumakov
Neal A
NA
Halsey
D000914:Antibodies, Viral / Q000097:blood; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D006166:Guatemala; D006801:Humans; D007223:Infant; D008297:Male; D011051:Poliomyelitis / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D011054:Poliovirus Vaccine, Inactivated / Q000008:administration & dosage* / Q000276:immunology*; D011055:Poliovirus Vaccine, Oral / Q000008:administration & dosage* / Q000276:immunology*; D017201:Virus Shedding
D000914:Antibodies, Viral; D011054:Poliovirus Vaccine, Inactivated; D011055:Poliovirus Vaccine, Oral