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PubMedDate not supplied

Improving the heat stability of vaccines: problems, needs, and approaches.

Biologics comprise temperature-sensitive organic polymers that must retain their primary and secondary structures as well as their interrelationships if their activities are to be retained. Targets for temperature-stable vaccines assume a technologic database that exceeds present knowledge. For this reason, new territory must be explored. Coupled with lack of scientific information is lack of economic incentive for the producer to undertake new areas of basic research on stabilization. Moreover, the means of protecting and rewarding the inventor are extremely weak, and no source of funds for meeting the costs is evident. It is critical, at this time, to weigh the costs of improving vaccine against those of establishing an effective cold chain. Developing a cold chain seems the more likely choice.

Drug Stability↗
PubMed1967

Lambda chains in cold agglutinins.

Type L light chains have been found in the cold agglutinins in the serums of three patients with chronic hemolytic anemia. Altholugh two of these cold agglutinins are unusual in that they do not have specificity to I or i red-cell antigens (one of these has, in addition, cryoglobuilin property), the third is a cold agglutinin of I specificity. Previously reported cold agglutinins from such patients have all been of type K; this is tlhe first report of type L cold agglutinins associated with chronic hemolytic anemia.

Anemia, Hemolytic, Autoimmune↗
PubMed2005

Introducing hepatitis B virus vaccine into the Expanded Programme on Immunization in Bangladesh: a proposed method to evaluate whether the existing infrastructure has the capacity.

To determine whether the existing Expanded Programme on Immunization (EPI) in Bangladesh has the capacity to introduce the hepatitis B virus (HBV) vaccine, this study was carried out in all the nine health facilities, which maintain a cold-chain, in Chandpur district of Bangladesh. The research, focusing specifically on cold-chain equipment, aimed at developing and applying an indicator of the use of cold-chain equipment. A structured questionnaire, developed and field-tested, was used for collecting information on cold-chain equipment and their use-rate. Data were used for estimating the resources needed to introduce the HBV vaccine and for increasing the coverage of measles and DPT vaccines. The findings of the study showed that the use-rate of cold-chain equipment in this district was low, suggesting that the district has sufficient spare capacity to introduce and sustain the storage of an increased quantity of vaccines. This paper suggests an approach to study capacity in relation to infrastructural facilities. By measuring the capacity of capital equipment, the study has illustrated that the measurement of resource-use rates provides useful information about the burden that a new vaccine places on the EPI.

Bangladesh↗
PubMedDate not supplied

Vaccine delivery management.

During the typical 12- to 18-month voyage of a vaccine from manufacturer to immunization site, many situations arise in which the cold chain may be interrupted. Extensive efforts have been made in the 1980s to ensure an uninterrupted cold chain through the use of improved equipment and better training of personnel. One important advance is the vaccine cold-chain monitor, which identifies weak spots in the cold chain and prevents the use of heat-damaged vaccine. Further improvements will require efforts by the recipient countries (e.g., better use of the private sector for transport and equipment management), by donor agencies (e.g., greater consideration of the operational and maintenance costs of the equipment selected and resolution of fuel shortages), and by industry (e.g., more appropriate packaging and pricing of vaccine, extension of the expiration period, and increased heat stability.

Cold Temperature↗
PubMed1997

Vaccine storage conditions in clinics in Colombo.

OBJECTIVES: To study the practices of health personnel regarding vaccine storage and the integrity of the cold chain, during storage, in immunisation clinics. DESIGN: A cross-sectional descriptive survey based on a postal questionnaire and an observational study of the cold chain during storage of a randomly selected sample. SETTING: Colombo District. PARTICIPANTS: 10 health centres, 13 Colombo Municipal Council Clinics, 26 general practices receiving vaccines from health centres, 13 private hospitals and 10 state-run hospitals. METHOD: A pretested postal questionnaire collected information on storage conditions and compliance with EPI requirements. The sub-sample in which the temperatures were monitored consisted of 33% of the total. The study was carried out in 1995-1996, when there was an uninterrupted power supply. OUTCOME MEASURES: Responses to the postal questionnaires and the colour changes recorded in thermosensitive WHO cold chain monitors. RESULTS: The response rate to the postal questionnaire was 87.5%. All 63 respondents stored vaccines in refrigerators worked by electricity. Information regarding refrigerators showed 46% to be less than 5 years old and 17% were more than 15 years old. 97% of refrigerators had good door seals. Regular defrosting was claimed by 79% of clinics and 81% had a named person responsible for vaccine storage. Only 57% had thermometers available and temperatures were monitored daily in only 40% of clinics. 76% of refrigerators were used for purposes other than storage of vaccines. Colour changes were noted in 2 out of 22 cold chain monitors.

Ambulatory Care Facilities↗
PubMed1996

Vaccine transport and storage: environmental challenges.

This paper describes the current status of the vaccine cold chain that was developed in the 1970s. It then describes the changes that are likely to take place in the next 5 to 10 years and their potential impact on the existing system. For more than 20 years, the cold chain system and vaccine handling rules have been set to the speed of the most fragile of the EPI vaccines namely: Oral Polio Vaccine. This has led to the establishment by WHO of stringent vaccine handling rules and Standard Performance Specifications for cold chain equipment. Major changes are occurring that will impact on immunization programmes: The introduction of Vaccine Vial Monitor (VVM), the prospect of an increase in the stability of OPV and the worldwide ban on refrigeration gases and insulation foaming agents.

Chlorofluorocarbons↗
PubMed2004

An analysis of clinical risks in vaccine transportation.

'Cold chain' transport is an integral part of a system of vaccine transportation that assures the potency of vaccines. If the temperature of vaccines is not kept between the ranges of 2 and 8 degrees C, this can lead to adverse effects especially for the recipients of first time immunization, as no protection is offered. This investigation has shown that there is considerable risk of vaccines being rendered impotent due to ad hoc collection of vaccines by healthcare professionals from pharmacy services, outside of the cold chain transport agreement with the vaccine supplier. This is because at present there are no guidelines for ad hoc collection of either vaccines or the approved cold chain equipment provided to transport the vaccine. The root cause analysis has shown that the general practice can manage this risk by making changes to its system for vaccine ordering, stock control and maintenance. A number of changes are proposed, including the appointment of a vaccine coordinator and the development of a protocol for ad hoc collection of vaccines from pharmacy. By focusing on improving the quality of the process, the practice can improve the care and safety of its immunization programme.

Humans↗
PubMedDate not supplied

Storage and handling of vaccines by family doctors.

The aim of this study is to see if vaccine storage and handling procedures used by family doctors in a health board region maintain vaccines at maximum potency. All 144 family doctors in the region were invited to be part of the study. Doctors were interviewed in their practice premises about procedures used in dealing with vaccines. Following the interview, practice fridges were examined and temperature recorded. Samples of oral polio were taken from 20 randomly selected fridges for potency testing. Cold chain monitors and freeze watch indicators were used to monitor batches of vaccine stored. Of the 144 doctors, 142 (98.6%) agreed to participate. Of these, 140 used 111 fridges to store vaccine, 2 doctors store vaccine at room temperature. Of the 111 fridges, 6 (5.4%) had the power supply safeguarded, 9 (8.1%) had thermometers, and 36 (32.4%) had vaccine only stored therein. During defrosting, the vaccine in 22 (19.8%) of the fridges was not adequately protected. Of the 138 doctors who use multi-dose vaccine vials, 133 (97.2%) keep them for further use at the end of a day/session, of whom 3 store them at room temperature. The temperature recorded in 42 (37.8%) fridges was outside the recommended range. Thirteen (28.2%) cold-chain monitors indicated vaccine exposed to more than 10 degrees C. Eighteen (90%) of the oral polio samples showed a reduction in total titre of live virus, however, none were below the minimum acceptable. This study indicates that vaccine potency could be seriously compromised due to breaks in the cold-chain and suggests the need for guidelines to be drawn up, implemented and monitored to ensure the integrity of immunisation schemes.

Adult↗