Israel Medical Association Journal

For children born after 1 January 2005, use of the Sabin oral polio vaccine in combination with the enhanced-potency Salk inactivated polio vaccine as part of the routine vaccination schedule was discontinued. The schedule now includes only IPV [1]. In September 2005, a fifth dose of pertussis vaccine was added for pupils in their second year of elementary school. This article describes the reasons for these changes, which have rendered Israel's routine vaccination program one of the most effective in the world.

Background: The evaluation of influenza vaccine activity and potency are based on the immune response to hemagglutinin, and protection is indicated when a ≥ 1:40 titer of hemagglutination inhibition serum antibody is present. Neuraminidase, the second surface glycoprotein, may also have a role in protection, but little information on the immunologic response to this component is available.

Objectives: To determine whether any response to neuraminidase is evoked by intranasal immunization with a novel, whole, inactivated anti-influenza vaccine.

Methods: This study was part of a more comprehensive study of mucosal and serum immune response to this vaccine. Fifty-four young adults were immunized intranasally, 9 intramuscularly and 18 received a placebo. Twenty-three elderly people were immunized intramuscularly, and 21 elderly and 17 children were immunized intranasally. Serum and nasal antibodies to antigens N1 and N2 were determined by the lectin neuraminidase test.

Results: Serum response following intranasal vaccination was lower than after intramuscular vaccination, and ranged from 21.4 to 35.3% and 33.3 to 64.7% following intranasal vaccination and 52.2 to 77.8% and 47.8 to 88.9% after intramuscular vaccination, to N1 and N2 respectively. Nasal antibody response was low and was found only after intranasal vaccination, and response to N2 was better than to the N1 antigen.

Conclusions: It may be beneficial if future vaccines would include competent hemagglutinin and neuraminidase, which would afford a higher level of protection.
 

Objectives: To assess the relative efficacy of clinical and laboratory methods in the diagnosis of Bordetella pertussis by patient age and immunization status.

Methods: We compared the clinical and laboratory diagnosis of B. pertussis in 87 pre-vaccinated, 78 recently vaccinated, and 75 post-vaccinated children with suspected pertussis. Serum and nasopharyngeal swabs were obtained for serology, culture and polymerase chain reaction.

Results: PCR[1] and culture identified 41% and 7% of patients with B. pertussis, respectively (P < 0.001). All positive cultures were PCR-positive. Positive PCR was less common among those recently vaccinated than among those in the pre- (P < 0.001) and post-vaccinated groups (P < 0.05). Positive culture was more common among those pre-vaccinated than among those recently vaccinated (P < 0.01). Positive tests for immunoglobulin M and A were more common among the post-vaccinated than the pre- and recently vaccinated (P < 0.001), respectively. Logistic regression analyses revealed that clinical criteria have no significant association with infection in recently and post-vaccinated children. Among the pre-vaccinated children, whoop and cough duration were associated with a positive PCR (odds ratio 7.66 and 0.5, P < 0.001). Seventy-six percent of pre-vaccinated, 39% of recently vaccinated and 40% of post-vaccinated children with positive PCR did not meet the U.S. Centers for Disease Control diagnostic criteria for B. pertussis.

Conclusions: PCR is a useful tool for pertussis diagnosis, particularly in pre-vaccinated infants. The yield of culture and serology is limited, especially among pre- and recently vaccinated children. In pre-vaccinated infants with whoop and less than 2 weeks of cough, PCR testing should be implemented promptly.

Background: Upper respiratory tract illnesses have been associated with an increased risk of morbidity and mortality.

Objective: To assess the influence of vaccination against influenza on the risk of hospitalization in internal medicine and geriatric wards, and the risk of death from all causes during the 2000–2001 influenza season.

Methods: A historical cohort study was conducted using computerized general practitioner records on patients aged 65 years and above, members of “Maccabi Health Care Services” – the second largest health maintenance organization in Israel with 1.6 million members. The patients were divided into high and low risk groups corresponding to coexisting conditions, and were studied. Administrative and clinical data were used to evaluate outcomes.

Results: Of the 84,613 subjects in the cohort 42.8% were immunized. At baseline, vaccinated subjects were sicker and had higher rates of coexisting conditions than unvaccinated subjects. Vaccination against influenza was associated with a 30% reduction in hospitalization rates and 70% in mortality rates in the high risk group. The NNT (number needed to treat) measured to prevent one hospitalization was 53.2 (28.2 in the high risk group and 100.4 in the low risk group). When referring to length of hospitalization, one vaccine was needed to prevent 1 day of hospitalization among the high risk group. Analyses according to age and the presence or absence of major medical conditions at baseline revealed similar findings across all subgroups.

Conclusions: In the elderly, vaccination against influenza is associated with a reduction in both the total risk of hospitalization and in the risk of death from all causes during the influenza season. These findings compel the rationale to increase compliance with recommendations for annual influenza vaccination among the elderly.

During September 2002, Israel began its current revaccination program against smallpox, targeting previously vaccinated “first responders” among medical and emergency workers. In order to identify the potential strengths and weaknesses of this program and the conditions under which critical decisions were reached, we conducted a SWOT analysis of the current Israeli revaccination program, designed to identify its intrinsic strengths and weaknesses, as well as opportunities for its success and threats against it. SWOT analysis – a practical tool for the study of public health policy decisions and the social and political contexts in which they are reached - revealed clear and substantial strengths and weaknesses of the current smallpox revaccination program, intrinsic to the vaccine itself. A number of threats were identified that may jeopardize the success of the current program, chief among them the appearance of severe complications of vaccination. Our finding of a lack of a generation of knowledge on smallpox vaccination urgently calls for improved physician education and dissipation of misconceptions that are prevalent in the public today.

Because of its high case-fatality rate, its very high transmission potential, and the worldwide shortage of effective vaccine, smallpox tops international lists of over a dozen possible bioterror and biologic warfare agents. In a scenario involving aerosol variola virus release, tens to hundreds of first-generation cases would ensue, as would hundreds to thousands of subsequent cases resulting from person-to-person transmission. A smallpox outbreak in Israel must not be regarded as a doomsday event: the methods of smallpox outbreak control are known and will be implemented. The rapidity with which organized outbreak control measures are competently executed will determine how many generations of cases occur before the outbreak is brought under control. Planning, vaccine stockpiling, laboratory expansion, professional training and public education, all carried out well in advance of an epidemic, will minimize the number of casualties. The reinstitution of routine smallpox vaccination in Israel, as in other countries, must be given serious consideration, since it has the potential for eliminating the threat of smallpox as a bioterror agent.

Methods: The study was conducted in the three general hospitals in Haifa City, and in five nursing homes in the Haifa subdistrict. Self-administered questionnaires were distributed to 1,014 employees of whom 71% were females, 34% were nurses, 27% were physicians and 28% were non-professional workers.

Results: The crude response rate was 66%. Response rates were higher in females (71%) than in males (49%), in nurses (70%) than in physicians (43%), and in staff of internal and pediatric departments than in workers of surgery departments and emergency rooms. The overall vaccination rate among the respondents was 11%, which was higher among males (15%) than among females (10%). No significant relationship between vaccination rate and age, occupation and department was found. The vaccination rate among employees with chronic illness was very low (7%). Influenza vaccine was actively recommended to 29% of the employees. The main reasons for non-compliance were low awareness of the severity of the disease and of the vaccine's efficacy and safety, and unavailability of the vaccine within the workplace.

Conclusions: Educational efforts and offering the vaccine at the workplace at no cost are the most important measures for raising influenza vaccination rates.