Canada Communicable Disease Report
Vol. 24 (ACS-2)
1 July 1998

An Advisory Committee Statement (ACS)
National Advisory Committee on Immunization (NACI)*

STATEMENT ON INFLUENZA VACCINATION FOR THE 1998-1999 SEASON

Erratum

STATEMENT ON INFLUENZA VACCINATION FOR THE 1998-1999 SEASON Vol. 24(ACS-2), Table 2

If you viewed this statement before 15 September 1998,
please note that there was an error in Table 2,
Recommended amantadine hydrochloride dosage by age and renal status.
Under Recognized renal disease, Creatinine clearance of 60-79 mL/min,
the Dosage for those 65 years should read "Alternating daily doses of 100 mg and 50 mg."

PREAMBLE

The National Advisory Committee on Immunization (NACI) provides Health Canada with ongoing and timely medical, scientific, and public-health advice relating to immunization. Health Canada acknowledges that the advice and recommendations set out in this statement are based upon the best current available scientific knowledge, and is disseminating this document for information purposes. Persons administering or using the vaccine should also be aware of the contents of the relevant product monograph(s). Recommendations for use and other information set out herein may differ from that set out in the product monograph(s) of the Canadian licensed manufacturer(s) of the vaccine(s). Manufacturer(s) have only sought approval of the vaccine(s) and provided evidence as to its safety and efficacy when used in accordance with the product monographs.

INTRODUCTION

The antigenic components of the influenza vaccine have been updated for the 1998-1999 season.  The present statement also contains updated sections concerning recent developments in the epidemiology of influenza, recommended vaccine recipients, and strategies for reducing the impact of influenza.

In Canada, two available measures can reduce the impact of influenza: immunoprophylaxis with inactivated (killed-virus) vaccine and chemoprophylaxis or therapy with an influenza-specific antiviral drug (amantadine). Vaccination of persons at high risk each year before the influenza season is currently the most effective measure for reducing the impact of influenza.

Influenza A viruses are classified into subtypes on the basis of two surface antigens: hemagglutinin (H) and neuraminidase (N). Three subtypes of hemagglutinin (H1, H2, and H3) and two subtypes of neuraminidase (N1 and N2) are recognized among influenza A viruses that have caused widespread human disease. Immunity to these antigens - especially to the hemagglutinin - reduces the likelihood of infection and lessens the severity of disease if infection occurs. Infection with a virus of one subtype confers little or no protection against viruses of other subtypes. Furthermore, over time, antigenic variation (antigenic drift) within a subtype may be so marked that infection or vaccination with one strain may not induce immunity to distantly related strains of the same subtype. Although influenza B viruses have shown more antigenic stability than influenza A viruses, antigenic variation does occur. For these reasons, major epidemics of respiratory disease caused by new variants of influenza continue to occur.

The 1997-1998 influenza season was characterized by a peak in activity between late January and early March. From September 1997 to April 1998, the Laboratory Centre for Disease Control (LCDC) received reports on 38,354 laboratory tests for influenza; 5,131 were confirmed as influenza A and 17 as influenza B. The provincial distribution of influenza A was as follows: Newfoundland (85), Nova Scotia (96), Prince Edward Island (5), New Brunswick (85), Quebec (765), Ontario (2,770), Manitoba (166), Saskatchewan (224), Alberta (560), and British Columbia (375). The provincial distribution of influenza B was as follows: Quebec (3), Ontario (13), and British Columbia (1). These results will, to some extent, reflect local testing policy and resources.

Since November 1997, strain characterization by LCDC has been completed on 440 influenza A isolates as follows: A/Sydney/5/97 (H3N2)-like (361), A/Wuhan/359/95 (H3N2)-like (71), and , A/Texas/36/91 (H1N1)-like (8). The provincial distribution of the 361 A/Sydney-like isolates was as follows: Newfoundland (10), Nova Scotia (6), Prince Edward Island (4), New Brunswick (4), Quebec (41), Ontario (198), Manitoba (14), Saskatchewan (38), Alberta (37), and British Columbia (9). The provincial distribution of the 71 A/Wuhan-like isolates was as follows: Nova Scotia (7), New Brunswick (1), Quebec (32), Ontario (19), Saskatchewan (4), Alberta (7), and British Columbia (1). All A/Texas-like isolates were from Ontario. One B/Beijing/184/93-like isolate was identified from Ontario.

A/Sydney/05/97 (H3N2)-like viruses were initially identified in Australia and New Zealand in June 1997. In Canada, the A/Sydney-like strain was first isolated from passengers aboard a cruise ship that sailed from New York to Montreal in September 1997⁽¹⁾. The A/Sydney-like influenza strain is related but antigenically distinguishable from the A/Wuhan/359/95 (H3N2)-like strain. Antibodies generated by the A/Nanching/933/95 (H3N2)-like virus strain, which was included in the 1997-1998 influenza vaccine and is antigenically equivalent to the A/Wuhan/359/95 (H3N2)-like strain, cross-react with A/Sydney/05/97 (H3N2)-like viruses⁽²⁾.  However, efficacy of the 1997-1998 influenza vaccine in individuals who were infected with A/Sydney/05/97 (H3N2)-like virus is unknown. Investigations of outbreaks of influenza A/Sydney/05/97 (H3N2)-like virus in three long-term care facilities and a military base in the United States in December 1997 and January 1998 suggest that the vaccine provided little protection against illness; however, in two of the long-term care facilities, vaccination may have reduced mortality⁽³⁾.

In the United States and Japan, peak influenza activity occurred in late January or early February 1998. Most European countries recorded the onset of activity towards the end of January or in the first half of February, and reported peak activity in the second half of February or the first week of March. However, in some European countries, regional activity continued to be reported in the first 3 weeks of April. Influenza A has been the predominant influenza type and, where influenza A has been further identified, the H3N2 subtype was most frequently reported. The United Kingdom and Israel have reported more H1N1 than other countries.

The antigenic characteristics of current and emerging influenza virus strains provide the basis for selecting the strains included in each year's vaccine. NACI recommends that the trivalent vaccine for the 1998-1999 season contain an A/Beijing/262/95 (H1N1)-like strain, an A/Sydney/5/97 (H3N2)-like strain, and a B/Harbin/7/94-like strain.

Annual immunization is required because there is always a change in the vaccine in response to antigenic drift. As well, immunity declines in the year following vaccination. Each 0.5 mL of vaccine will contain 15 µg hemagglutinin of each antigen. The vaccine will be available as a split-virus (chemically disrupted) preparation. Protection from the vaccine generally begins about 2 weeks after immunization and may last 6 months or longer. However, in the elderly, antibody levels fall below protective levels in 4 months or less. Thus, November is the preferred time for immunization of elderly individuals. Nevertheless, annual vaccination programs, such as those for residents of long-term care facilities, should begin as soon as vaccine is available in September or early October to ensure high coverage prior to significant circulation of influenza. No opportunity should be missed to give vaccine to any individual at risk who has not been immunized during the current season.

RECENT DEVELOPMENTS IN INFLUENZA EPIDEMIOLOGY AND IMMUNIZATION

This section provides a brief review of interesting developments in influenza epidemiology and immunization since the last NACI statement.  Where applicable, elements from this section have been applied to the section entitled "Recommended Recipients".

• Avian influenza: As of 12 March 1998, 18 cases of influenza A (H5N1) ("bird flu" or "avian flu") have been confirmed by virus isolation or serology⁽⁴⁾. All cases occurred in residents of the Hong Kong Special Administrative Region. The date of onset of illness of the last case was 28 December 1997. Six persons have died of the disease. The eight RNA gene segments from the influenza A (H5N1) isolates that have been analyzed are derived from avian viruses; genetic reassortment between avian and human influenza viruses has not been demonstrated⁽⁵⁾. This influenza strain was previously known to infect only birds. Seroepidemiologic studies suggest that persons exposed to infected poultry or to the virus in the laboratory may be at increased risk for infection with influenza A (H5N1) virus⁽⁵⁾. It is not presently known whether person-to-person transmission occurs; however the low rates of seropositivity among contacts of cases suggests that the virus is not efficiently transmitted between humans⁽⁵⁾. At this time, the World Health Organization has not recommended the production of an influenza A (H5N1) vaccine for general use.
• Influenza A outbreak on a cruise ship:  Investigation of an outbreak of influenza A/Sydney/05/97 (H3N2)-like virus on a cruise ship travelling between New York City and Montreal revealed that many cruise ship passengers are elderly and have one or more risk factors for influenza-related complications⁽¹⁾. Ships provide a closed setting where influenza transmission may readily occur between international passengers and crew who are in close proximity to each other. The infection control measures utilized during the influenza outbreak on the ship were similar to those recommended for outbreaks in long-term care facilities. This outbreak illustrates the need to promote vaccination among those at risk for influenza complications as well as among those who provide services to these individuals within relatively closed settings that facilitate transmission of infection. Health-care workers and employees of service providers must identify these settings and provide education and immunization programs for their clients, patients, and employees.
• Influenza immunization in multiple sclerosis: A recent multicentre randomized double-blind placebo-controlled trial of influenza immunization in patients with multiple sclerosis showed neither an association with the rate of exacerbation of neurologic disease rate in the post-vaccination period, nor a change in disease course over the subsequent 6 months⁽⁶⁾. Recommendations for the prevention and control of influenza during the 1998-1999 influenza season follow.

RECOMMENDED RECIPIENTS

Current influenza vaccines licensed in Canada are immunogenic, safe, and associated with minimal side effects⁽⁷⁾ (see "Adverse reactions", and "Contraindications and precautions").  Influenza vaccine may be administered to any healthy child, adolescent, or adult for whom contraindications are not present.

In order to reduce the morbidity and mortality associated with influenza and the impact of illness in our communities, public-health immunization programs should focus on those at high risk for influenza-related complications, those capable of transmitting influenza to individuals at high risk for complications, and those who provide essential community services⁽⁸⁾.  However, persons who wish to protect themselves from influenza should be encouraged to receive the vaccine even if they are not in one of these groups.

People at high risk

• Adults and children with chronic cardiac or pulmonary disorders (including bronchopulmonary dysplasia, cystic fibrosis and asthma) severe enough to require regular medical follow-up or hospital care. Chronic cardiac and pulmonary disorders are by far the most important risk factors for influenza-related death⁽⁹⁾.
• People of any age who are residents of nursing homes and other chronic care facilities. Such residents often have one or more of the medical conditions outlined in the first group. In addition, their institutional environment may promote spread of the disease. Studies have shown that the use of vaccine in this setting will decrease the occurrence of illness and has an even greater impact on reducing the rates of hospital admission, pneumonia, and death^(10,11).
• People >= 65 years of age. The risk of severe illness and death related to influenza is moderately increased in healthy people in this age group^(12,13), but is not as great as in people with chronic underlying disease. Vaccination is effective in preventing hospital admission and death, and results in direct health-care cost savings^(14,15).
• Adults and children with chronic conditions, such as diabetes mellitus and other metabolic diseases, cancer, immunodeficiency, immunosuppression (due to underlying disease and/or therapy), renal disease, anemia, and hemoglobinopathy. The degree of risk associated with chronic renal and metabolic diseases in children is uncertain, but this uncertainty should not preclude consideration of vaccination.
• Children and adolescents (age 6 months to 18 years) with conditions treated for long periods with acetylsalicylic acid. This therapy increases the risk for developing Reye syndrome after influenza⁽⁷⁾.
• Persons infected with HIV. Limited information exists regarding the frequency and severity of influenza illness among HIV-infected persons, but reports suggest that symptoms may be prolonged and the risk for complications increased for some HIV-infected persons. Because influenza can result in serious illness and complications, vaccination is a prudent precaution and will result in protective antibody levels in many recipients. However, the antibody response to vaccine may be low in persons with advanced HIV-related illnesses⁽¹⁶⁾; giving a second dose of vaccine 4 or more weeks after the first dose not improve the immune response for these persons. HIV load does not increase with influenza immunization according to a randomized placebo-controlled trial in adults⁽¹⁷⁾ and an uncontrolled descriptive report in children⁽¹⁸⁾.
• People at high risk of influenza complications embarking on travel to destinations where influenza is likely to be circulating. These individuals should be vaccinated with the most current available vaccine. Immunization may be considered for all individuals who wish to avoid influenza while travelling to areas where influenza is likely to be circulating. In the tropics, influenza can occur throughout the year. In the southern hemisphere, peak activity occurs from April through September. In the northern hemisphere, peak activity occurs from November through March. Travel may expose individuals to situations which facilitate the transmission of influenza⁽¹⁾. The effectiveness of the influenza immunization for travellers may vary depending on differences between influenza strains encountered abroad and those included in the current vaccine.

People capable of transmitting influenza to those at high risk

People who are potentially capable of transmitting influenza to those at high risk should receive annual vaccination.

• Health-care workers and other personnel who have significant contact with people in the high-risk groups previously described. The following groups should be vaccinated^(1,7,19,20): health care-workers in long-term care facilities, hospitals and outpatient settings; employees of long-term care facilities who have patient contact; and, those who provide services within relatively closed settings to persons at high risk (e.g. providers of home-care services, crew on ships that cater to those at high risk, household members of those in high-risk groups).
• Household contacts (including children) of people at high risk who either cannot be vaccinated or may respond inadequately to vaccination. Because low antibody responses to influenza vaccine may occur in some people at high risk (e.g. the elderly, people with immunodeficiency)^(16,21); annual vaccination of their household contacts may reduce the risk of influenza exposure.

People who provide essential community services

Vaccination may be considered for these individuals in order to minimize the disruption of routine activities in epidemics. Employers and their employees should consider yearly influenza immunization for healthy working adults as this has been shown to decrease work absenteeism from respiratory and other illnesses^(22,23).

RECOMMENDED USE

The recommended dosage schedule and type of influenza vaccine are presented in Table 1. Split-virus vaccines are available in Canada. During the 1998-1999 influenza season, there will be no inactivated whole-virus vaccine available in Canada. Children < 9 years of age require two doses of the split-virus influenza vaccine, with an interval of 4 weeks; however, the second dose is not needed if the child received one or more doses of vaccine prepared for a previous season.

In infants < 6 months of age, influenza vaccine is less immunogenic than in infants and children aged 6 to 18 months. Therefore, immunization with currently available influenza vaccines is not recommended for infants < 6 months of age⁽²⁴⁾.

Table 1 Recommended influenza-vaccine dosage, by age, 1998-1999

Intramuscular administration is preferred because data relating to influenza vaccine have generally been obtained after such administration. The deltoid muscle is the recommended site in adults and older children, the anterolateral thigh in infants and young children.

Adverse reactions

Influenza vaccination cannot cause influenza because the vaccine does not contain live virus. Soreness at the injection site lasting up to 2 days is common, but rarely interferes with normal activities. Fever, malaise, and myalgia may occur within 6 to 12 hours after vaccination and last 1 to 2 days, especially in young adults who have received the whole-virus vaccine and those receiving vaccine for the first time. Prophylactic acetaminophen may decrease the frequency of some side effects in adults⁽²⁵⁾. Adults receiving the split-virus vaccine showed no increase in the frequency of fever or other systemic symptoms compared to those receiving placebo⁽²⁶⁾. In children aged 2 to 12 years, fever and local reactions are no more frequent after administration of split-virus vaccine than after placebo injections. In those < 24 months of age, fever occurs more often but is seldom severe.

Allergic responses are rare and are probably a consequence of hypersensitivity to some vaccine component, most likely residual egg protein, which is present in minute quantities.

Unlike the 1976-1977 swine influenza vaccine, subsequent vaccines prepared from other virus strains between 1978 and 1991 have not been clearly associated with an increased frequency of Guillain-Barré syndrome (GBS). In a recent study of the 1992-1993 and 1993-1994 seasons in the United States⁽²⁷⁾, investigators found an elevation in the overall relative risk for GBS during the 6 weeks following vaccination, representing an excess of an estimated one to two cases of GBS per million persons vaccinated over the background incidence of 10 to 20 cases per million adults. This increase may be the result of vaccination but also could be the result of other factors such as confounding or diagnostic bias (in contrast, during the 1976-1977 season, the rate of GBS that exceeded background was just under 10 cases per million persons vaccinated). In Canada, the background incidence of GBS is similar, estimated at just over 20 cases per million population in a study done in Ontario and Quebec⁽²⁸⁾. Persons with a history of GBS have a substantially greater likelihood of subsequently developing GBS, but whether influenza vaccination might be causally associated with this risk for recurrence is not known. Nevertheless, avoiding subsequent influenza vaccination of persons known to have developed GBS within 6 weeks of a previous influenza vaccination seems prudent.

Influenza vaccine is not known to predispose to Reye syndrome.

Please refer to the Canadian Immunization Guide⁽²⁹⁾ for further details about administration of vaccine and management of adverse events.

Contraindications and precautions

Influenza vaccine should not be given to people who had an anaphylactic reaction to a previous dose or with known anaphylactic hypersensitivity to eggs manifested as hives, swelling of the mouth and throat, difficulty in breathing, hypotension, and shock.

Individuals with acute febrile illness usually should not be vaccinated until their symptoms have abated.

Influenza vaccine is considered safe for pregnant women at all stages of pregnancy. Vaccination is recommended for pregnant women in high-risk groups (see "Recommended Recipients"). Although the routine of immunization of otherwise healthy women in the second or third trimester of pregnancy has been recommended by the American Advisory Committee on Immunization (ACIP)⁽⁸⁾, NACI concludes that there is insufficient evidence at this time to recommend this practice in Canada^(30-35).

Influenza immunization does not adversely affect the health of breast feeding mothers or their infants. Breast feeding is not a contraindication for influenza immunization.

Although influenza vaccination can inhibit the clearance of warfarin and theophylline, clinical studies have not shown any adverse effects attributable to these drugs in people receiving influenza vaccine.

Simultaneous administration of other vaccines

The target groups for influenza and pneumococcal vaccination overlap considerably. Health-care providers should take the opportunity to vaccinate eligible persons against pneumococcal disease during the same visit at which influenza vaccine is given. The concurrent administration of the two vaccines at different sites does not increase the risk of side effects. Pneumococcal vaccine, however, is usually given only once, whereas influenza vaccine is given annually. Children at high risk may receive influenza vaccine at the same time but at a different site from that used for routine pediatric vaccines.

Storage

Influenza vaccine should be stored at 2^o C to 8^o C and should not be frozen.

STRATEGIES FOR REDUCING THE IMPACT OF INFLUENZA

The effectiveness of influenza vaccine varies depending upon the age and immunocompetence of the vaccine recipient, the degree of similarity between the virus strain included, and the strain of circulating virus during the influenza season. With a good match, influenza vaccination has been shown to prevent illness in approximately 70% of healthy children and adults. Under these circumstances, studies have also shown influenza vaccination to be approximately 70% effective in preventing hospitalization for pneumonia and influenza among elderly persons living in the community. Studies among elderly persons residing in nursing homes have shown influenza vaccination to be 50% to 60% effective in preventing hospitalization and pneumonia, and up to 85% effective in preventing death, even though efficacy in preventing influenza illness may often be in the range of 30% to 40% among the frail elderly.

Vaccination is recognized as the single most effective way of preventing or attenuating influenza for those at high risk of serious illness or death. Influenza vaccine programs should aim to vaccinate at least 90% of eligible recipients. Nevertheless, only 70% of long-term care facility residents and 20%to 40% of adults and children with medical conditions listed previously receive vaccine annually^(36,37). Studies of health care workers in hospitals and long term care facilities have shown vaccination rates of 26 to 61%^(38-40).

This low rate of utilization is due to both failure of the health-care system to offer the vaccine and refusal by those for whom vaccine is recommended because they fear adverse reactions or believe that the vaccine is either ineffective or unnecessary^(40-44). Educational efforts aimed at physicians and the public should address common concerns about vaccine effectiveness and adverse reactions. These include the beliefs of patients at risk, health-care workers, and other service providers that they rarely get influenza; the fear of side effects from the vaccine; and doubt about the efficacy of the vaccine. Health-care workers and their employers have a duty to implement and comply with influenza immunization recommendations in order to decrease the risk of infection and complications in the patients for whom they care.

The advice of a health-care provider is often a very important factor affecting whether a person is immunized or not⁽⁴⁵⁾. Most people at high risk are already under medical care and should be vaccinated during regular fall visits. Strategies to improve coverage include

• standing-order policies in institutions allowing nurses to administer vaccine
• simultaneous immunization of staff and patients in nursing homes and chronic-care facilities
• vaccinating people at high risk who are being discharged from hospital or visiting the emergency room in the autumn
• promoting influenza vaccination in clinics which see high-risk groups (e.g. cancer clinics, cardiac clinics, pulmonary clinics)
• using community newspapers, radio, television, flu-information lines, and collaborating with pharmacists and specialist physicians to distribute positively-framed information about the benefits and risks of immunization⁽⁴³⁾
• issuing computer-generated reminders to physicians, mailing reminder letters to patients, or using other recall methods to identify outpatients at high risk
• patient-carried reminder cards
• increased accessibility of immunization clinics to staff in institutions and community-based elderly, including the implementation of mobile programs⁽³⁸⁾
• organized activities, such as vaccination fairs and competitions between institutions
• working with multicultural groups to plan and implement effective programs.

RECOMMENDATIONS FOR THE USE OF AMANTADINE

Amantadine hydrochloride is an antiviral agent that interferes with the replication cycle of type A (but not type B) influenza viruses. Recommendations for its use in prophylaxis and treatment follow.

Prophylaxis

The only drug currently approved in Canada for the specific prophylaxis of influenza virus infections is amantadine hydrochloride. It is 70% to 90% effective in preventing illness caused by type A influenza viruses but is ineffective against type B strains. Because antiviral agents taken prophylactically may prevent illness but not subclinical infection, some persons who take these drugs may still develop immune responses that will protect them when they are exposed to antigenically-related viruses in later years. However, amantadine prophylaxis should not replace annual influenza vaccination in groups for whom vaccine is recommended.

Amantadine prophylaxis may be used as follows:

• For the control of influenza A outbreaks among high-risk residents of institutions. Amantadine should be given to all residents, whether previously vaccinated or not, and to unvaccinated staff (see "Precautions"). Consultation with the local medical officer of health to confirm that the circulating influenza strain is type A is essential.
• As the sole agent for prophylaxis in people at high risk during an outbreak when vaccine is unavailable, contraindicated, or unlikely to be effective due to a shift in the antigenic composition of the outbreak strain. In this case, prophylactic amantadine must be taken each day for the duration of influenza A activity in the community.
• As an adjunct to late vaccination of people at high risk. Amantadine should be continued for 2 weeks after appropriate vaccination is completed; that is, for those receiving two doses of vaccine, amantadine should be continued for 2 weeks after the second dose.
• As a supplement to vaccination in people at high risk expected to have an impaired immune response to vaccine. This includes persons with HIV infection, especially those with advanced HIV disease. No data are available on possible interactions with other drugs used in the management of patients with HIV infection. Such patients should be monitored closely if amantadine is administered.
• For unvaccinated people who provide home care for people at high risk during an outbreak. Amantadine prophylaxis should be continued until 2 weeks after the care provider has been vaccinated.

Treatment

Amantadine has been shown to reduce the severity and shorten the duration of influenza A in healthy adults. Although there have been no well-controlled studies to demonstrate its efficacy in preventing complications in people at high risk, amantadine may be considered for those at high risk who have suspected influenza A because of the potential benefits. The drug should be administered within 24 to 48 hours after the onset of illness and continued until 2 days after its resolution. Amantadine-resistant influenza viruses may emerge during treatment but there is no evidence that these viruses are more virulent or transmissible than amantadine-sensitive influenza viruses. However, the consequences of widespread therapeutic use of amantadine are not known. Studies to assess this issue are required.

Dosage

Recommendations for dosage are presented in Table 2, but the package insert should be read for complete information. Any adjustments for renal function should be made in addition to adjustments for age.

Table 2 Recommended amantadine hydrochloride dosage by age and renal status

Precautions

In otherwise healthy young adults given amantadine prophylactically, 5% to 10% report difficulty concentrating, insomnia, light-headedness, and irritability. These side effects are usually mild and cease shortly after the prophylaxis is stopped; however, they can be more frequent in the older population unless a reduced dosage is used.

Serious side effects (e.g. marked behavioural changes, delirium, hallucinations, agitation, seizures) have been associated with high plasma drug concentrations. These have been observed most often among persons who have renal insufficiency, seizure disorders, or certain psychiatric disorders, and among elderly persons who have been taking amantadine as prophylaxis at a dose of 200 mg/day. Lowering the dosage among these persons is effective in combatting the severity of such side effects.

Amantadine is not metabolized but is excreted in the urine. Therefore, in people with reduced renal function, particularly the elderly, toxic levels can occur if the dosage is not reduced. Table 2 shows the recommended dosage by age and renal function. The dosage should be reduced in people with a seizure disorder to avoid the risk of increased frequency of seizures. The patient's age, weight, renal function, and the presence of other underlying conditions should be considered, and the dosage adjusted accordingly. In addition, patients should be carefully monitored for side effects.

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37. DeWals P, Carbonneau M, Payette H et al. Influenza and pneumococcal vaccination in long term care facilities in two regions of Quebec. Can J Infect Dis, 1996:7;296-300.

38. Adal KA, Flowers RH, Anglim AM et al. Prevention of nosocomial influenza.  Infect Control Hosp Epidemiol 1996;17:641-48.

39. Doebbeling BN, Edmond MB, Davis CS et al. Influenza vaccination of health care workers: evaluation of factors that are important in acceptance. Prev Med 1997;26:68-77.

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* Members: Dr. V. Marchessault (Chairman), Dr. J. Spika (Executive Secretary), N. Armstrong (Advisory Committee Secretariat Officer), Dr. G. De Serres, Dr. P. DeWals, Dr. I. Gemmill, Dr. B. Law, Dr. M. Naus, Dr. P. Orr, Dr. W. Schlech III, Dr. B. Ward.

Liason Members: Dr. J. Carsley (CPHA), Dr. G. Delage (CPS), Dr. T. Freeman (CFPC), Dr. S. Hadler (CDC), Dr. J. Livengood (CDC), Dr. N MacDonald (CIDS), R. McLaren (COHNA), Dr. A. McCarthy (ND), Dr. J. Salzman (CATMAT), Dr. J. Waters (ACE).

Ex-Officio Members: Dr. M. Carew (MSB), Dr. P. Duclos (LCDC), Dr. L. Palkonyay (LCDC).

[Canada Communicable Disease Report]