Volume 7, Number 2, August 1999
Adapted from the final report of the 13th meeting of the PAHO Technical Advisory Group
The 13th meeting of the Pan American Health Organization (PAHO) Technical Advisory Group (TAG) on Vaccine-Preventable Diseases was hosted by Health Canada and held in Hull, Quebec, from April 12 to 16, 1999. TAG meets every 2 years and functions as the leading forum to promote regional initiatives aimed at controlling and eliminating vaccine-preventable diseases. Representatives from PAHO member countries meet to review the current status of vaccine-preventable diseases and immunization programs in the countries of the Region.
During the Hull meeting, emphasis was placed on the need to highlight the role that immunization has played in reducing the incidence of vaccine-preventable diseases. This impact can be further increased if countries find the means to introduce other vaccines in a sustainable way. The following are excerpts of the final report on the conclusions and recommendations of the meeting.
Introduction
The Region of the Americas enters the new millennium with great promise and strength. Additional vaccines are being added to the basic schedule every year, and the Region is making progress towards ensuring that these vaccines are of known quality. Much remains to be done, however, especially in reaching those people who are not currently benefiting from immunization services and those who could already be enjoying the advantages of vaccination against diseases that carry a significant health burden.
On the other hand, there is a tendency for complacency that goes hand in hand with the success achieved by immunization worldwide. Efforts are needed to disseminate more widely the value of vaccines to individuals and the community at large.
Immunization coverage levels remain at above 80% throughout the Americas, and thus the vast majority of children are being reached with the basic vaccination schedule. The strength of these programs lies in a panamerican approach to tackling important public health problems. The historic poliomyelitis eradication in the Americas was the product of the collective action of collaborating agencies, countries and beneficiaries alike in the pursuit of a common objective. This collaboration has enabled many countries in the Region to acquire the necessary tools to improve their health situation by themselves.
1. Impact of Decentralization and Health Sector Reform on National Immunization Programs
The processes of health reform and decentralization of health services are well under way in the countries of the Americas. Although laws have been enacted that transfer decision-making and resources to the local levels, in practice there is a need to clarify the responsibilities of the various institutions assigned to the delivery of immunization services, as well as the mechanisms to transfer and manage resources. These changes are causing delays, especially in the allocation of resources for routine vaccination activities and for emergency outbreak situations in some countries.
Several countries going through the process of decentralization and health reform are showing a decline in process indicators for immunization programs, such as coverage and surveillance. This could have serious implications, both nationally and internationally, for immunization programs, especially for measles eradication. National governments should make special efforts to maintain the quality and effectiveness of national immunization programs, so that no areas become a reservoir to seed infection into other communities and countries.
Recommendations
Financing
Delivery of Immunization Services
Programmatic
2. Measles Eradication
Great progress has been made towards interrupting measles transmission in most countries of the Americas. However, measles virus continues to circulate in several areas of the Region, and only 21 months remain until the target date of achieving the goal of hemispheric measles eradication.
Recommendations
Vaccination Strategies
Outbreak Response
Surveillance and Laboratory
3. Rubella and Congenital Rubella Syndrome
Rubella virus continues to circulate freely in most countries of the Region. After a complete investigation, many suspected measles cases are ultimately found to be rubella. Moreover, cases of CRS have been found in all countries of the Region that have established CRS surveillance systems. This suggests that CRS is a major public health problem in all countries of the Americas.
Recommendations
Vaccination Strategies
Surveillance and Laboratory
4. Poliomyelitis
The Region of the Americas remains at constant risk of polio importations from countries where the virus still circulates widely. Poliovirus is now largely confined to South Asia, West Africa, Central Africa, and the Horn of Africa. However, there have already been two importations detected in Canada since the confirmation of the last case of acute flaccid paralysis (AFP) due to wild poliovirus in the Americas in 1991.
National data continue to show deterioration in the surveillance of AFP in some countries. It is critical that the AFP surveillance system remain fully functional to rapidly detect poliovirus throughout the Region, should the virus be re-introduced.
The eradication of polio from the Western hemisphere is a well-known public health milestone. After 7 years of maintaining the Region polio-free, it would be a tragedy if polio were re-established in the hemisphere. A high level of commitment should be maintained at the political level in every country, to protect the population and prevent the re-establishment of the disease in the Region.
Recommendations
General
Laboratory
5. Neonatal Tetanus
Tremendous progress has been made in eliminating neonatal tetanus (NNT) as a public health problem throughout the Americas. In 1998, there were 223 reported cases of NNT from 16 countries in the Region. This represents an 85% reduction in cases since intensive efforts were instituted in 1988.
Recommendations
6. Yellow Fever
Although no case of urban yellow fever has been reported in the Region since 1942, more than 1,900 cases of sylvatic (jungle) yellow fever have been reported from Bolivia, Brazil, Colombia, Ecuador, Peru, French Guyana, and Venezuela over the past 10 years. Although all of these infections were acquired in endemic areas, many of the cases were diagnosed and reported in urban environments. The widespread dissemination of the Aedes aegypti mosquito throughout the Americas makes the re-urbanization of yellow fever an increasing concern.
The seriousness of the yellow fever problem in the Region requires a commitment by countries at risk to implement appropriate vaccination and surveillance strategies for controlling and preventing the disease.
Recommendations
7. Haemophilus influenzae Type b Vaccine
Safe and effective Haemophilus influenzae type b (Hib) vaccines are available. These vaccines have had a significant impact in reducing the incidence of Hib disease in countries where the vaccine has been introduced in routine infant immunization programs and high coverage has been obtained. Remarkable progress has been achieved in the introduction of Hib vaccine in the Americas. By December 1999, PAHO estimates that 81% of all newborns in the Region (75% in Latin America and the Caribbean) will be living in countries where Hib vaccine is included in routine infant immunization schedules.
Recommendations
Combination Vaccines
8. Rotavirus Vaccine
Worldwide, rotavirus infection contributes significantly to infant and child morbidity and mortality as a result of diarrheal diseases. In developing countries, rotavirus accounts for a sizeable proportion of all deaths due to diarrhea, especially in children < 5 years of age.
A live, orally administered rotavirus vaccine became available in 1998. Although rotavirus vaccine is a potential candidate for inclusion in national immunization programs, a better understanding of rotavirus epidemiology and burden of disease in different countries is needed. Each country will eventually need to weigh the economic implications of introducing the vaccine into its immunization schedule.
Recommendations
9. Vaccines of Quality
Using vaccines of proven quality is essential for immunization programs. Although the manufacturer is primarily responsible for ensuring vaccine quality, there should be a national authority in each country that performs the six basic regulatory functions: licensing, clinical evaluation, Good Manufacturing Practices (GMP) inspections, lot release, laboratory testing, and post-marketing surveillance. PAHO has been strengthening the vaccine quality control system in the Region by organizing a network of certified national control laboratories responsible for the quality testing of vaccines and by harmonizing regulatory procedures of the national regulatory authorities of all countries.
Recommendations
10. Hepatitis B
It has been estimated that as many as 400,000 new hepatitis B infections occur annually in the Americas. In highly endemic areas, transmission occurs primarily perinatally or in early childhood. In areas with intermediate endemicity, infection occurs in all age groups. In areas of low hepatitis B seroprevalence, most infections occur in adults, especially in persons belonging to defined risk groups. Since the development of chronic infection is age-dependent, children can account for a high proportion of chronic hepatitis B infections. The risk of chronic infection is highest when infection is acquired early in life.
Recommendations
11. Safe Syringe Practices
Non-sterile injection practices remain a problem in some areas. Insufficient supplies of syringes and needles seem to be a major factor. Unsafe injections can result in the transmission of bloodborne pathogens from person to person.
Recommendations
12. Immunization Safety
Immunizations have reduced the incidence of vaccine-preventable diseases throughout the world. Public trust in national immunization programs is important to maintain. Although modern vaccines are safe and effective, no vaccine is entirely without risk and significant adverse events. The regular monitoring of immunization safety will provide technical and scientific assurance of the safety of vaccines utilized.
Recommendations
Technical Advisory Group Members
John Peter Figueroa (Jamaica), Donald A. Henderson, Chairman (United States), Akira Homma (Brazil), John La Montagne (United States), Joseph Z. Losos (Canada), Fernando MuZoz Porras (Chile), Walter Orenstein (United States), Roberto Tapia Conyer (Mexico) and Ciro A. De Quadros, Secretary Ad-Hoc (United States).
Editorial Note: The Canadian National Advisory Committee on Immunization (NACI) recommendation regarding rubella vaccination and pregnancy is that women of childbearing age should be advised to avoid pregnancy for 1 month after vaccination. NACI also recommends that inquiry regarding pregnancy should be made before vaccination, and administration of vaccine to pregnant women should be avoided.
Adapted from Fact Sheet No. 15, Division of Vaccines and Immunization, Pan American Health Organization, Washington, D.C.
Following a resurgence of measles cases in the Region of the Americas in 1997, the number of cases reported declined in 1998. As the year 2000 approaches, collaboration among all who are working to eradicate measles is more important than ever, so we can make this goal a reality!
Four years have passed since the goal of measles eradication from the Americas was established at the 1994 Pan American Sanitary Conference. The majority of countries in the Region continue to successfully control measles and prevent large outbreaks with the Pan American Health Organization's (PAHO) recommended vaccination strategy for measles eradication. While great progress has been made towards achieving this goal with a marked reduction in the annual number of reported cases, measles virus continues to circulate in a few countries of the Region.
The ramifications of the measles outbreak in southern Brazil in late 1997, with over 52,284 confirmed cases, continue to affect countries of the southern cone, particularly Argentina, Bolivia and Paraguay. For 1998, the provisional confirmed cases in the Region of the Americas stands at 12,940, which represents a 75% reduction in measles cases when compared to confirmed cases in 1997. The measles outbreaks in Brazil and Argentina in 1997 and 1998 have again demonstrated the lethality of measles virus. Over 100 measles-related deaths have been reported in the past 2 years in both countries; most occurred among unvaccinated infants and preschool-aged children.
These outbreaks underscore the extreme infectivity of measles virus and the importance of achieving and maintaining high measles immunity in infants and preschool-aged children, especially those living in urban environments. Experience in the Americas is showing that the high population density of cities greatly facilitates measles virus circulation between infected and susceptible individuals, especially when the number of susceptible infants and children is high because of low vaccination coverage in routine measles programs.
There are four major remaining challenges to complete the Region's measles eradication goal by the year 2000.
First | The countries of the Americas need to keep up their guard by maintaining the highest population immunity possible in infants and children through routine immunization services. |
Second | All countries need to carry out follow-up measles vaccination campaigns among children 1 to 4 years old, at least every 4 years to avoid the accumulation of susceptible children. This is an important component of the vaccination strategy recommended by PAHO for measles eradication. |
Third | All the countries in the Americas should place high priority on measles surveillance to conduct rigorous case and outbreak investigations. |
Fourth | The countries should assign sufficient resources to maintain adequate stocks of measles vaccines and other supplies, to carry out routine immunization services, to conduct scheduled follow-up vaccination campaigns and to quickly implement control measures in the event of an outbreak. |
PAHO is urging countries to take a pro-active approach to prevent measles outbreaks. Outbreaks have been opportunities, however, to reinforce surveillance and to obtain the necessary political commitment to meet the goal of measles eradication by the year 2000. Considerably greater efforts are needed, however, in analyzing these outbreaks, disseminating lessons learned among health workers, and translating this information to decision-makers at the policy level.
It will be critical to implement PAHO's recommended vaccination strategy for measles eradication in full, and include other groups potentially at high-risk for measles, such as health care workers, college and university students and faculty, military personnel and people working in the tourist industry. For measles eradication, annual routine vaccination coverage must be at least 95% in every district or municipality of every country of the Region, and follow-up campaigns must be conducted among children 1-4 years of age at least every 4 years.
Together we will eradicate measles from the Americas!
Starting with this issue, the Update will feature, on an ad-hoc basis, a Qs and As section which will highlight significant or frequently asked immunization-related questions, and responses provided by national or provincial/territorial public health authorities knowledgeable in the specific issues, or by expert advisory committees. The purpose of this feature is to disseminate as widely as possible information that may be relevant to immunization programs and program staff who may be faced with similar questions. This service is being coordinated by the Division of Immunization to share and promote sharing of information by readers with common interests or concerns. While the questions may be edited, they will be kept as close as possible to the original to reflect real-life situations in the field. All attempts will be made to make the information provided in the Qs and As factually accurate and consistent with national policies and guidelines, however, the information does not necessarily represent official Health Canada policy. Readers who have information that can be shared in this section should contact the editorial staff.
Q: We have a child who was immunized with a vaccine called Tetralife or Tetra.... - the vaccination record is not legible. I am assuming it is a form of DPT-Hib. I am also wondering if this would have been a whole-cell pertussis vaccine. Are you able to enlighten us about the infant immunization schedules for South Africa. (Saskatchewan)
A: Information on the World Health Organization (WHO) Expanded Program on Immunization (EPI) schedule may be obtained from the website for WHO's Department of Vaccines and Biologicals (formerly Global Programme for Vaccines and Immunization) at www.who.int/gpv/. For country-specific immunization information, select "Diseases + Vaccines", "Country Immunization Profiles", then "Alphabetic Index". There is also an option to download Excel files of country-specific vaccination schedules and vaccination coverage levels. This website is an invaluable resource for any local/regional/provincial/territorial vaccine provider or public health staff (provided they have Internet access) to obtain basic immunization information for questions arising when serving clients from other countries. (Division of Immunization, LCDC)
Note: Additional information on a South African vaccine manufacturer was obtained through an Internet search for "Tetralife" and provided with the response, as a potential source of information on the specific vaccine product.
We wish to remind our readers that the future of this publication depends upon the readers' interest and contributions. We believe, and have received feedback from the field, indicating that this newsletter is an invaluable forum for provinces/territories to highlight achievements or developments of interest and to share information about their VPD programs/activities with > 1,200 public health recipients. We continue to encourage active submission of reports on programmatic, policy or epidemiologic issues for publication.
The Update now includes an "Upcoming Conferences/Events" section to highlight national conferences/meetings related to VPDs; we would like readers to keep us informed of such events.
Submissions may include original material or previously published material and should be sent to the attention of VPDU Editors via fax (612-952-7948), e-mail (adwoa_bentsienchill@hc-sc.gc.ca) or by mail (Attn: VPDU Editors, Division of Immunization, Bureau of Infectious Diseases, LCDC, Tunney's Pasture PL 0603E1, Ottawa, Ontario K1A 0L2).
Volume 6, No. 4 - Paragraph 5, Page 36
Please note in paragraph 5, 4th line, "(up to 25 per
10,000 cases(6))" should read (up
to 25 per 100,000 cases).
Confirmed Measles Cases in Canada
by Week of Onset*
(January 1 to June 30, 1999) |
||
Week Ending |
Onset of Rash |
Confirmed Cases |
2 Jan |
53 |
0 |
9 Jan |
1 |
0 |
16 Jan |
2 |
0 |
23 Jan |
3 |
0 |
30 Jan |
4 |
1 |
6 Feb |
5 |
1 |
13 Feb |
6 |
0 |
20 Feb |
7 |
1 |
27 Feb |
8 |
0 |
6 Mar |
9 |
0 |
13 Mar |
10 |
0 |
20 Mar |
11 |
0 |
27 Mar |
12 |
0 |
3 Apr |
13 |
0 |
10 Apr |
14 |
0 |
17 Apr |
15 |
0 |
24 Apr |
16 |
0 |
1 May |
17 |
0 |
8 May |
18 |
0 |
15 May |
19 |
0 |
22 May |
20 |
1 |
29 May |
21 |
0 |
5 Jun |
22 |
0 |
12 Jun |
23 |
0 |
19 Jun |
24 |
0 |
26 Jun |
25 |
0 |
TOTAL |
-- |
4 |
* Based on confirmed cases reported to the Enhanced Measles Surveillance System, Division of Immunization, LCDC. |
Cumulative number of cases
reported* for
selected
vaccine-preventable diseases, Canada
January 1997 - June 1999
Disease |
January-June 1997 |
January-June 1998 |
January-June 1999 |
Diphtheria |
1 |
0 |
1 |
Haemophilus influenzae type b |
12 |
15 |
11 |
Measles§ |
382 |
8 |
4 |
Mumps |
154 |
35 |
24 |
Rubella¶ |
2,305 |
41 |
13 |
Congenital rubella syndrome |
1 |
1 |
0 |
Pertussis |
1,114 |
772 |
1,659 |
Paralytic poliomyelitis |
0 |
0 |
0 |
Tetanus |
1 |
0 |
0 |
* Based on cases reported to the Notifiable Disease Reporting System, Division of Disease Surveillance, LCDC; 1998 and 1999 data are provisional. Also cumulative totals for the current year to date may not represent national totals due to incomplete reports from provinces/territories. § Measles data are based on confirmed cases reported to the Enhanced Measles Surveillance System, Division of Immunization, LCDC. ¶ Approximately 98% of rubella cases reported in 1997 have been reported from Manitoba where an outbreak of rubella occurred, starting October 1996 through December 1997. |
National Immunization Awareness Week October 25-30, 1999 |
National Immunization Registry "Trade Show" Regina December 6-8, 1999 |