Analytical summary - Immunization and vaccines development
According to WHO guidelines, a child is considered fully immunized if he or she has received:
- a vaccination against tuberculosis (Bacille Calmette-Guérin, BCG)
- three doses of diphtheria, pertussis and tetanus (DPT) vaccine
- three doses of pneumococcal conjugate vaccine (PCV)
- at least three doses of polio vaccine
- one dose of measles vaccine.
These vaccines should be received during the first year of life.
Since 2002, Malawi has replaced the DPT vaccine with pentavalent vaccine that protects against DPT, hepatitis B (HepB) and Haemophilus influenzae type B (Hib). In Malawi, BCG and polio vaccine should be given within the first 14 days after birth, and the DPT-HepB-Hib, PCV and polio vaccines should be given at approximately 6, 10 and 14 weeks of age. The measles vaccine should be given when, or soon after, the child reaches 9 months of age. It is recommended that children receive the complete schedule of vaccination before their first birthday.
The proportion of children who are fully immunized at 12 months of age has remained relatively low. In 2005, only 59% of children aged 12–23 months were fully vaccinated by 12 months of age. Over the years, Malawi has sustained high routine immunization coverage of over 80% for childhood antigens, achieving a non-polio acute flaccid paralysis rate of 2.7% and a measles rate of over 2%. In 2010, there were outbreaks of measles countrywide. The major challenges faced by the programme include mobilization of resources for responding to outbreaks of vaccine-preventable diseases and for introduction of new vaccines.
Malawi conducted a cold chain assessment in 2011 and not only came up with an inventory of cold chain equipment but also identified capacity requirements that needed to be strengthened. The report made recommendations on a number of programme components that need strengthening at both national and district levels, including the development and implementation of the cold chain rehabilitation and expansion plan for 2011–2015. As part of the plan, Malawi is constructing a national vaccine store and renovating the regional vaccine stores. The plan also addresses transportation and cold chain training as a way of strengthening immunization systems.
The Malawi Ministry of Health and Population, in collaboration with WHO and the United Nations Children’s Fund, conducted an assessment of maternal and neonatal tetanus elimination in Malawi in 2002. The results of the assessment suggest that Malawi has achieved neonatal elimination. The survey found an incidence rate of less than 1 neonatal case per 1000 live births in the three districts. The success of the immunization programme in Malawi, with about 80% of all women having received at least two doses of tetanus toxoid vaccine, has contributed to this low incidence.
The WHO African Region adopted regional measles pre-elimination targets to be met by the end of 2012 and has been working towards these targets since 2008. At the end of 2011, WHO conducted an assessment of the country performance against the pre-elimination goals. Based on the performance, Malawi is on track to meet the measles pre-elimination targets for 2012.
The acute flaccid paralysis surveillance report 2010 indicated that out of the 6.4 million population aged less than 15 years, there were 118 non-polio acute flaccid paralysis cases reported, giving a non-polio acute flaccid paralysis rate of 1.8 against a targeted rate of 2.0. The percentage of acute flaccid paralysis cases with adequate stool samples was 78% compared with the target of 80%. All of the 118 acute flaccid paralysis cases were discarded as non-polio acute flaccid paralysis, thus Malawi is on track to achieve polio eradication.
In November 2011, Malawi launched a new vaccine called PCV, which protects children against diseases such as pneumonia, meningitis, otitis media and bacteraemia and is provided, like other vaccines, through the Expanded Programme on Immunization. It is expected that about 660 000 children aged under 1 year will receive the PCV vaccine annually. Despite the efforts that the Government of Malawi, in collaboration with different partners, is directing towards making sure that children are vaccinated, there are still some communities that do not allow their children to be vaccinated. This will have implications on the effectiveness of the vaccine.
In Malawi Hib surveillance has been carried out at the Queen Elizabeth Central Hospital in Blantyre for almost 10 years. The site captures data on Haemophilus influenza, Streptococcus pneumonia, Nesseria meningitis and non-specific meningitis.
Malawi is among seven African countries taking part in a malaria vaccine trial. This is a double-blind (observer-blind), randomized and controlled multicentre study to evaluate, in infants and children, the efficacy of the RTS, S/AS01E candidate vaccine against malaria disease caused by Plasmodium falciparum infection, across diverse malaria transmission settings in Africa.
This phase III study of GSK Biologicals candidate malaria vaccine RTS, S/AS01E has been designed to address the key safety and efficacy information required for vaccine licensure. The first results of the study were released in October 2011. The results suggested that the vaccine is about 56% efficacious against clinical malaria. The research trial, which started 2 years ago, will run for 5 years.