Immunization, Vaccines and Biologicals

Malaria

Malaria is a global health priority. It occurs in 99 countries and more than 3 billion people are at risk of acquiring the disease. In 2010, there were an estimated 219 million cases of malaria, and 660 000 malaria deaths globally. Approximately 80% of cases and 90% of deaths are estimated to occur in the WHO African Region, with children under five years of age and pregnant women most severely affected.

Malaria is preventable and effective interventions are available. Immunization programmes can play a role in the delivery of several key malaria interventions:

• Long-lasting insecticidal nets (LLINs)
• Intermittent Preventive Treatment in Infants (IPTi-SP)
• Intermittent Preventive Treatment in Pregnant Women (IPTp)
• Future malaria vaccines

1. Long-lasting insecticidal nets (LLINs)

Long-lasting insecticidal nets (LLINs) have played an important role in the remarkable success in reducing malaria burden over the past decade. They are a core prevention tool, and widely used by people at risk of malaria.

For LLINs WHO recommends:

1. Universal coverage remains the goal for all people at risk of malaria.

2. In order to maintain universal coverage, countries should apply a combination of mass free distributions and continuous distributions through multiple channels, in particular antenatal and immunisation services. Mass campaigns are a cost-effective way to rapidly achieve high and equitable coverage, but coverage gaps start to appear almost immediately post-campaign through net deterioration, loss of nets, and population growth, requiring complementary continuous distribution channels.

The delivery mechanism may be a direct distribution or through vouchers to pregnant women and/or children at the time of vaccination:

• LLINs have been successfully integrated with many measles and polio mass vaccination campaigns.
• LLINs have been distributed at antenatal contacts (for example with TT vaccination) and have the advantage of allowing protection of both pregnant women and children under the age of one year if the infant is sleeping with the mother.
• LLINs have been distributed with routine immunization services, either at the first contact (BCG or DTP1) if the mother has not previously received an LLIN, or at the measles vaccination contact (MCV1 or MCV2) which can serve as an incentive for completing the child’s full vaccination schedule.

Key resources

• Continous LLIN distributions : A Guide to Concepts and Planning (Dec 2011)

• Country to Country Guide for Implementers of LLIN Keep Up: A Guide for Continuous Delivery of LLINs via ANC, EPI and Other Routine Health Services (Dec 2011)

Grabowsky M. et al. (2005) Integrating insecticide treated bednets into a measles vaccination campaign achieves high, rapid and equitable coverage with direct and voucher based methods. Tropical Journal of Medicine and International Health.vol 10 (11) 1151-1160.

Grabowsky M. et al. (2005) Integrating Insecticide treated bednets during measles vaccination: a low cost means of achieving high and equitable coverage. Bulletin of the World Health Organization 83 (3).

MMWR. Distribution of Insecticide Treated Bednets During an Integrated Nationwide Immunization Campaign - Togo, West Africa, December 2004.

MMWR. Distribution of Insecticide Treated Bednets During a Polio Immunization Campaign - Niger 2005.

2. Intermittent Preventive Treatment in pregnancy (IPTp)

Malaria infection during pregnancy is a major public health problem, with substantial risks for the mother, her fetus and the neonate. Intermittent preventive treatment of malaria in pregnancy is a full therapeutic course of antimalarial medicine given to pregnant women at routine prenatal visits (which may include TT vaccination), regardless of whether the recipient is infected with malaria. IPTp reduces maternal malaria episodes, maternal and fetal anaemia, placental parasitaemia, low birth weight, and neonatal mortality.

WHO recommends IPTp with sulfadoxine-pyrimethamine (IPTp-SP) in all areas with moderate to high malaria transmission in Africa. As of October 2012, WHO recommends that this preventive treatment be given to all pregnant women at each scheduled antenatal care visit except during the first trimester. WHO recommends a schedule of four antenatal care visits. Based on currently available evidence, the preventive efficacy of SP for IPTp persists even in areas where quintuple mutations linked to SP resistance are prevalent in P. falciparum.

3. Intermittent Preventive Treatment in Infants (IPTi)

Intermittent preventive treatment in infants is a full therapeutic course of antimalarial medicine delivered to infants through routine immunization services, regardless of whether the child is infected with malaria. WHO recommends IPTi with sulfadoxine-pyrimethamine (IPTi-SP) in areas with moderate to high malaria transmission in sub-Saharan Africa that have less than 50% prevalence of pfdhps 540 mutation in the P. falciparum parasite.

IPTi reduces clinical malaria, anaemia and severe malaria in the first year of life. Treatment is given three times during the first year of life at approximately 10 weeks, 14 weeks, and 9 months of age, corresponding to the routine vaccination schedule of the Expanded Programme on Immunization (EPI).

Key documents

J. Crawley et. Al. Effect of intermittent preventive treatment for malaria during infancy on serological responses to measles and other vaccines used in the Expanded Programme on Immunization: results from five randomised controlled trials. Lancet. www.thelancet.com. Published September 12, 2012.

4. Malaria Vaccines

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