Israel Medical Association Journal

Background: According to the Israeli immunization schedule 1 year old babies should receive two concomitant vaccinations: MMR (measles-mumps-rubella), and DTap-Hib-IPV (diphtheria tetanus acellular pertussis-Haemophilus influenzae type b-poliomyelitis). However, about one-third of infants in Israel receive these vaccinations separately. Nurses at a primary care prevention clinic in Israel observed that the separate mode of vaccination is associated with a lower rate of side effects.

Objectives: To validate this observation and determine whether it represents an exception or the rule.

Methods: A nested prospective follow-up study was conducted in a primary care clinic in Israel. The survey included 191 mothers and their offspring born during 2004/2005. The mothers were interviewed over the telephone 2 weeks after the day of vaccination.

Results: The rate of adverse effects in children who received the injections separately was significantly lower than among those who were vaccinated simultaneously (40% vs. 57%).

Conclusions: It may be necessary to reconsider the current vaccination policy regarding concomitant injections.

Background: In trials comparing different formulations of measles vaccine, excess non-specific mortality occurred in female children who received high titer vaccine. These findings suggest a gender-specific effect of measles vaccine.

Objectives: To determine whether gender differences exist in the rates of adverse reactions and morbidity in the month following immunization with measles-containing vaccine, and to evaluate whether there is a gender-specific association between the humoral immune response to measles vaccination and post-vaccination morbidity.

Methods: Parents completed questionnaires on the health status of 755 infants aged 15-20 months, during the month preceding and the month following the measles-mumps-rubella vaccination. Blood samples were tested for measles antibody titers in a subsample of 237 infants.

Results: After controlling background morbidity in the infants, the relative risk of fever and rash following vaccination was 2.35 in females and 1.36 in males. The geometric mean antibody titers against measles were similar in both sexes and there was no significant association between antibody titer and post-vaccination morbidity in either sex.

Conclusions: Our findings demonstrate higher rates of adverse effects in females following vaccination with MMR vaccine, irrespective of the humoral response. This study emphasizes the need to consider possible gender differences when evaluating new vaccines.

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MMR= measles-mumps-rubella