LIMITADO BENEFICIO CLINICO Y CON REDUCCIÓN DE LA RESPUESTA A LAS VACUNAS CON LA ADMINISTRACION PREVENTIVA DE ACETAMINOFEN

Amigos y amigas,

La administración profilactica al momento de la vacunación disminuye significativamente la reacción febril y no afecta realmente la ocurrencia de fiebre mayor de 39 grados centígrados. Sin embargo, disminuye la respuesta inmune a algunos antígenos de la hexavalente y de la vacuna antineumocóccica. Asi, la indicación rutinaria preventiva previos a la vacunación de antipireticos, tipo acetaminofén, debe ser eliminada a menos que este prescrita por otra razón medica.

Muy interesante la conclusión de una investigación muy importante que se realizo en Checoslovaquia por un grupo liderizado por el Dr. Prymula, ver abajo. Tuve el gusto de conocerlo en la presentación y discusión de su poster hecha en el EUROPEDIATRICS 2009celebrado en la ciudad de Moscu, Rusia, el pasado 2 al 6 de julio. Me informo el Dr. Prymula que la publicación del trabajo fue aprobada por LANCET para los próximos números.

R455
LIMITED CLINICAL BENEFIT BUT REDUCED ANTIBODY RESPONSES TO PEDIATRIC VACCINES FOLLOWING PROPHYLACTIC PARACETAMOL ADMINISTRATION

Prymula R., Siegrist C., Chlibek R., Zemlickova H., Vackova M., Smetana J.,
Lommel P., Kaliskova E., Dorota B., Schuerman L.
Faculty of Military Health Sciences, University of Defence, Hradec Kralove,
Czech Republic Center for Vaccinology and Neonatal Immunology, University of Geneva,
Geneva, Switzerland Centre of Epidemiology and Microbiology, National Institute of Public Health, Prague, Czech Republic Global Clinical Development Center,GlaxoSmithKline Biologicals, Rixensart, Belgium
GlaxoSmithKline Biologicals, Prague, Czech Republic

Background. Fever is frequently part of the normal inflammatory response after immunization in young children. Although generally benign and self limiting, it is frequently of concern for parents and physicians.

Aim. Evaluation of impact of prophylactic antipyretic administration on reactogenicity and immunogenicity.

Patients and methods. Paracetamol (acetaminophen; AP group) was prophylacticly administered in 3–4 doses at 6–8 h intervals within the first 24 h after each vaccination dose of the licensed DTPaHBVIPV/Hib vaccine coadministered with a 10valent pneumococcal conjugate vaccine at 3–4–5 months of age (107017/NCT00370318)
followed by a booster dose at 12–15 months (107137/NCT00496015). Reactogenicity/immunogenicity was compared with a group of vaccinees not receiving prophylactic antipyretics (NAP group).

Results. Fever within 4 days after vaccination was statistically significantly reduced in the AP group; 41.6% (94/226)subjects with rectal temperature  38°C vs 66.1% (154/233) after primary vaccination; 36.0% (64/178) vs 58.1% (100/172) after booster. No effect was observed on the occurrence of fever > 39.5°C or requiring medical attention. Seroprotection/seropositivity rates were high (> 96%), within similar ranges for both groups at all time points, and also in line with previous experience with DTPaHBVIPV/Hib vaccine. However lower geometric mean antibody
concentrations (GMCs) were observed in the AP group for some antigens (D, T, PRN, PRP) after priming. Seroprotection rates were not impacted for most antigens and boostability was maintained. Only antitetanus GMC remained lower after the booster. A reduction was also observed for most antipneumococcal responses in these
studies, as well as in posthoc analyses (across several studies) for primary vaccination with the licensed 7valent pneumococcal conjugate vaccine.

Conclusions. Even if prophylactic administration of paracetamol at the time of vaccination significantly reduced febrile reactions, no effect on the occurrence of fever > 39.5°C was observed. However, decreased immune responses
to some antigens of different paediatric vaccines were observed. Therefore, routine prophylactic administration of antipyretics should be discouraged unless medically justified.

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