Immunisation Programs in Africa
The not so compulsory cold chain?
By Ariane Halm (EPIET Fellow Cohort 13, HPA/CfI,UK)
Mali
Epidemiologist at work in the field in Mali
In 1999, more or less the first step in my career took place in a small town in Guinea (Conakry), West Africa. When I got the mission to Mali ten years later, it meant I got to go back to some of my professional roots – what a joy!
Africa not only has a better climate (in my opinion) and more sun than our fields, but it can also be home to some less good news, such as numerous infectious diseases as well as at times very scarce resources. Most people will know that vaccines are sensitive to heat, and it is generally recommended they be kept under controlled low temperatures (2-8ºC). Ensuring this “cold chain” is a challenge everywhere, but it becomes particularly difficult in settings where electricity and equipment are scarce.
What many people may not know is that despite the restrictive storage guidelines there is actually leeway in the temperatures vaccines can be stored under, and that there is potential to greatly relieve pressure on the logistics & supply chain and increase flexibility for healthcare staff.
Vaccine Vial Monitors (VVMs) are temperature- and time-sensitive stickers placed on individual vaccine vials that measure the cumulative heat exposure. They serve as indicators as to whether a vaccine is well enough preserved to be administered, or if the heat exposure endpoint has been reached and the vial should be discarded.
OPV vials with VVMs
The live-attenuated oral polio vaccine (OPV) is the most heat-sensitive of those currently included in the Expanded Programme for Immunisation. It is often used as part of national vaccination campaigns working towards the goal of global eradication of poliomyelitis. These campaigns aim to vaccinate all children under five years with OPV, and they constitute an important organisational and logistical enterprise.
During these vaccination campaigns, the cold chain faces additional problems: (1) the weight of the icepacks that have to be carried often for several hours and long distances, as well as (2) the humidity generated by the icepacks that soaks the vaccine labels often resulting in their detachment, destruction or lack of readability, consequently leaving the vaccine unusable even if the vial is still full.
Polio vaccination campaigns represent a good opportunity to perform a study of OPV under “out of the cold chain” (OCC) conditions, i.e. without icepacks. There is a need to document OCC use as it is a (re-)current practice but there is a lack of scientific literature of its field application. Together with ex-EPIET fellow Olivier Ronveaux (cohort 3) who works at the World Health Organization in Geneva, we performed a study during the latest polio immunisation round in Mali in May/ June 2009. Our aim was to demonstrate that OCC use for OPV during a mass vaccination campaign is feasible, beneficial and safe.
Besides being an interesting and meaningful area of research, it fits in nicely with my pharmacy and supply background.
We did a crossover intervention trial in the southern district of Sélingué, which actually borders my former home Guinea. All vaccination teams in the study area applied both, icepack (=cold chain) and OCC procedures on alternating days during the vaccination activities. The study was based on VVM status classification, continuous temperature recordings and a couple of questionnaires to be filled out by vaccination teams and campaign supervisors. It was preceded by a training of all teams on VVM readings and data collection tools.
Some vaccination teams, mostly composed of people without specific or health-related training, walk for 5-20 km under the African sun (temperatures up to 40ºC) carrying the filled vaccine carrier and other campaign tools (polio markers, chalks, tally sheets, etc.). For most of us, this would seem quite an outrageous undertaking.
Typical polio campaign vaccine carriers
Despite this and against some of our initial fears, the study went very well. We had a response rate from the vaccinations teams (97%) that I think would have proved difficult to achieve where I am currently working. Furthermore, our results confirm that under controlled circumstances OPV can be kept OCC without being damaged despite high ambient temperatures – good news that should be explored further.
In addition to this, I learned that woman needs to be corpulent so that man knows she is going to work hard, and was reminded afresh that it is much better to relax and not get stressed about e.g. time (not easy for a German, I can assure you), because things will mostly somehow work out anyways. And that it is better to try and see the positive side and keep your sense of humour. Admittedly, this is easier under the sunshine while being constantly fed with mangos than under the London rain.
Last but not least, the mission also included the obligatory West African music everywhere, the odd dancing experience, eating “riz sauce” with your hands, as well as the delight of the evenings’ cold beer – all in all a fantastic diversion from swine flu.
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Zero la vie
By Lorenzo Pezzoli (Epiet Cohort 12, Temporary Advisor for WHO)
Cameroon
Traditional housing in the Extreme North of Cameroon
Cameroon is often described as Africa in miniature, since most of the beautiful African landscapes and amazing wildlife species can be found there. Unfortunately, among the typical Cameroonian wildlife we can count also some dangerous members that are not exactly tourist attractions. Like elsewhere in Africa, mosquitoes are vectors of the yellow fever virus and of the malaria plasmodium, just to cite two very serious mosquito-borne infections endemic in Cameroon. Another very dangerous wild species is also present in Cameroon, the Wild poliovirus, and it is not unusual to still find cases of poliomyelitis in Cameroon and in the neighbouring countries of Nigeria, Central African Republic, and Chad.
Luckily both yellow fever (YF) and poliomyelitis (Polio) are vaccine preventable diseases and vaccination campaigns are conducted in Cameroon for primary prevention or outbreak control. The National YF and Polio Vaccination Campaign covered 62 health districts in Cameroon between the 4 and the 11 of May 2009.
I had the opportunity to work in Cameroon between 16 April and 21 May 2009 as a consultant for the World Health Organization (WHO). WHO is currently experimenting rapid techniques to evaluate vaccine coverage during vaccination campaigns to guide timely mop-up actions. With this intention, during the vaccination campaign we implemented the Lot Quality Assurance Sampling (LQAS) methodology in 17 districts at risk for low coverage across the country. It was a very intense period of hard work for all the team, which included experts of the Ministry of Health (MoH), the National Institute of Statistics (NIS), and WHO. Protocol writing, recruiting the surveyors, training them, coordinating all the local teams and at the same time conduct surveys ourselves, data entering, data analysis, report writing, certainly kept us busy.
The study was very rewarding and, although many of the at-risk districts were found with sub-optimal levels of coverage, we recommended an extension of the vaccination campaign of two days to increase the vaccination coverage in the areas of weakness.
The LQAS Study Team in Yaoundé (from left to right): Mr. Ndjomo (NIS), Mr. Takeu (NIS), Dr. Tchio (MoH), Mr. Dzossa (NIS), and m
This mission was also a great opportunity for me to learn more about this truly amazing country. I was very lucky to find excellent colleagues and friends, who not only supported me through the many challenges of a national vaccination campaign, but also transmitted me a very positive and enthusiastic attitude.
In five weeks in Cameroon, I not only gained more experience in vaccination coverage surveys, but I learned how to maintain optimism even when things seem not to go the way they are planned and how differences most of the time can be seen as opportunities. I have also realized that life is zero, zero la vie, as a famous singer from Yaoundé says, so we should make the best of it, without feeling overwhelmed by circumstances as we do too often. In addition, I have also acquired excellent skills in bargaining at the local markets, which is also very useful in the time of the credit-crunch.
Every day we learn something different and every experience should prepare us for the next one, especially, but not only, in epidemiology. I am sure that remembering the lessons from Cameroon will be very useful here in London, the most diverse city I know, where every day something different happens. The first thing I did once I landed was trying to discuss the price of the Heathrow Express. That did not work so well, I must say, and I still had to pay the full ticket. But after implementing the LQAS in cities like Yaoundé or Maroua, perhaps I should transfer the methods to Hampstead and check the MMR coverage. Most importantly, I am trying to remember that life should not be a stressful business. Although, as we all know too well, nothing is 100% effective, remembering this simple lesson makes things better, sometimes... For example, when a tube strike or a signal failure on the Northern Line blocks me in the underground, now I just play zero la vie on my iPod and enjoy the music.
Dr Ticha (WHO) getting vaccinated in the city of Maroua to set the good example
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Yellow Fever AEFI Surveillance
By Gabrielle Breugelmans (Epiet Cohort 7, Agence de Médecine Préventive (AMP), France)
Africa
50 dose presentation of diluent for yellow fever vaccine
Although I have been working for the last six years in vaccines it was not until I started working at AMP two years ago that I became more familiar with the ins and outs of vaccine safety monitoring. As we all know, vaccines are a major public health triumph by protecting the individual and the public from vaccine preventable diseases. Although modern vaccines are safe, no vaccine is entirely without risk. Some people experience events after vaccination ranging from mild side effects to life-threatening, but rare, illnesses. In some cases, these reactions or events are caused by the vaccine; in others, they are caused by an error in the administration of the vaccine; and in the majority of cases, there is no relationship.
Whatever the cause, when somebody experiences an Adverse Event Following an Immunization (the socalled AEFI or “MAPI” in French) this can have a big impact to the extent that people refuse further vaccinations for themselves or their children, with all kind of possible consequences.
Luckily for most of us in Europe vaccine safety is strictly regulated and any notice of a possible vaccine related AEFI well investigated. This is unfortunately not the case for those in Africa where surveillance to monitor the safety of vaccines, medications or medical devices is sorely lacking.
Like Lorenzo, I had the opportunity to go several times to Cameroon over the past four month as member of the Yellow Fever partnership to support Ministries of Health in West and Central Africa to implement yellow fever AEFI surveillance as part of their mass yellow fever vaccination campaigns.
Although my missions to Cameroon were mainly concentrated in lush green, hilly, and temperate Yaoundé, the political capital of Cameroon (Douala is Cameroon’s economic hub), it was a very pleasant change of West Africa (e.g. Burkina Faso, Mali) where temperatures easily reach >40°C in the dry season. Cameroon falls in the so-called Yellow Fever Belt in Africa and Yellow Fever is endemic in the country. In 2007 Cameroon, which is a GAVI (Global Alliance for Vaccines and Immunization) eligible country (i.e., its’ gross national income per capita was US$ 1000 or less in 2003), applied to the Yellow Fever Initiative for funding to conducts its preventive Yellow Fever campaign. This Initiative, led by WHO and UNICEF, with the support of GAVI, targets the implementation of Yellow Fever immunization campaigns between 2006 and 2013 in 12 African countries. Furthermore, the Initiative will provide funding in the amount of approximately 290 million US$ to vaccinate 180 million people with the highly effective attenuated 17D YF vaccine. Within the framework of the Initiative, the 12 Member States and WHO will identify specific target populations to vaccinate, with the aim of both preventing outbreaks and managing epidemics, and consequently increasing immunization coverage. One condition to obtain funding is to include AEFI surveillance as an integral part of the yellow fever campaign.
Local poster to announce the combined yellow fever / polio vaccination campaignSetting up AEFI surveillance in a country with no existing pharmacovigilance system is no small task. As nothing was in place six weeks before the start of the campaign many hours were spent in developing an operational guide, preparing notification and investigations forms, operational procedures for biological sample collection and management, training on AEFI surveillance for the different actors in the field, and last but certainly not least communication tools for crisis management. Although time was extremely limited (isn’t it always!) the team at the Ministry of Health still managed to have everything ready on May 4th, the first day of the vaccination campaign. Between May 4 – 11, in total 7.5 million people 9 months and older (pregnant women, the extremely ill, and those with egg allergy excluded) in 62 districts in Cameroon were vaccinated. Although the vaccination campaign lasted only one week the AEFI monitoring period lasted until June 10 (30 days after the end of the vaccination activities) in order not to miss possible serious AEFIs that may develop up to four weeks after vaccination. As we speak (June 22, 2009), the personnel of the EPI (Expanded Program on Immunisation) office of the Ministry of Health in Yaoundé are still busy with data entry of hundreds of forms while preparing at the same time for the upcoming measles campaign at the end of this month.
Working with the EPI and WHO personnel in Cameroon was a true pleasure and I admire the enthusiasm and perseverance of the staff as working in the public health sector in Cameroon is just plain challenging due a constant lack of materials, funds, high morbidity and mortality rates and so forth. I have very fond memories of the good times and stories shared over a cold Castle beer, steamed or fried plantains (type of banana that is omnipresent) and a plate of Ndole, which is made of boiled, shredded bitterleaf (a type of green), peanuts, and melon seeds. It is seasoned with spices and hot oil, and can be cooked with fish or meat. Ndole is definitely not a “light” dish but extremely tasty and should be enjoyed slowly, like many things in Africa!
