Immunization and Malaria Eradication

Introduction:

The tremendous adaptability of the parasites and the vector that transmit the disease makes malaria challenging to control. While effective measures have been discovered and will continue to be developed to treat malaria, it is inevitable that if those tools are utilized in isolation or ineffectively, the parasites and mosquitoes will evolve mechanisms to escape them. Healthcare workers will need a combination of innovative techniques and equipment to manage malaria successfully, and research will be crucial in creating these cutting-edge tactics.

What Is Malaria?

• Malaria is a disease that occurs when an infected mosquito (with a parasite) bites a person.

• The mosquito injects malaria parasites into the bloodstream when it bites humans. Instead of a virus or a specific type of bacteria, parasites cause malaria.

• Malaria can result in serious health issues such as convulsions, brain damage, breathing difficulties, organ failure, and even death if it is not treated.

How Widespread Is Malaria?

• Tropical regions with high temperatures and humidity are prone to malaria.

• There were 627,000 malaria-related deaths in 2020, with 241 million documented disease cases worldwide. Most of these occurrences take place in South Asia and Africa.

What Causes Malaria?

• A mosquito gets infected when it bites a person who has malaria. The parasite mosquito enters the bloodstream of the person it bites. The parasites grow there. Humans can contract one of five different types of malaria parasites.

• In some instances, pregnant women with malaria may pass the illness to their unborn children.

• Although improbable, malaria can spread through hypodermic needles, organ transplants, and blood transfusions.

What Are the Signs and Symptoms of Malaria?

Malaria symptoms and signs can include the following:

• Fever.

• Chills.

• General discomfort.

• Headache.

• Nausea and vomiting.

• Diarrhea.

• Stomach ache.

• Joint or muscle aches.

• Fatigue.

• Breathing rapidly.

• Swift heartbeat.

• Cough.

The first signs and symptoms of malaria usually appear a few weeks after being bitten by an infected mosquito. Some malaria parasite strains, however, can rest in the bloodstream for up to a year.

How Is It Diagnosed?

A blood test is used to identify the disease. A blood test will detect parasites in the blood and the type of malaria parasite.

How Is It Treated?

Malaria treatment must start as soon as feasible. But, the doctor will first prescribe medications to kill the malaria parasite. Some drugs are given in combination with other drugs. Type of parasite will determine which medication they must receive and how long they must take it.

The following are the most widely used antimalarial drugs:

• Artemisinin-Based Combination Therapy (ACTs): ACT is a formulation of two or more medications that work in different ways to attack the malaria parasite. In most cases, this is the suggested course of action for malaria that is chloroquine-resistant. Two examples are Artesunate-Mefloquine and Artemether-Lumefantrine (Coartem).

• Other Medications: Atovaquone, Chloroquine (ineffective against some parasites), Doxycycline, Mefloquine, Primaquine, and Quinine.

What Is Immunization?

Immunization is the process of receiving the vaccine and developing immunity to the disease. Immunization has a significant role in primary healthcare. Currently, it prevents 2 to 3 million vaccine-preventable disease-related deaths annually.

What Vaccines Are Available for Malaria?

The RTS,S malaria vaccine was officially recommended for wider use among children in sub-Saharan Africa and other areas with moderate or high malaria transmission on October 6th by the World Health Organization (WHO). This is the first time that vaccination for malaria, a disease that has killed billions of people worldwide over many centuries, has been suggested.

What Is RTS,S?

• A vaccination called RTS,S/AS01 (RTS,S) protects against Plasmodium falciparum, the deadliest malaria parasite in the world and the most common in Africa.

• The WHO recommended the vaccination for a pilot introduction in particular regions of three African nations in January 2016.

• The WHO-recommended core set of preventative, diagnostic, and treatment strategies is being supplemented (rather than replaced) with RTS,S as a complementary tool for malaria control.

• P. vivax malaria, the most common type and prevalent in many nations outside of Africa, is not protected against by vaccination.

What Are the Other Vaccines That Are Under Development for Malaria?

• Whole sporozoites, the sexual form of the parasite taken from mosquito salivary glands, are another exciting possibility for a malaria vaccine. These sporozoites are either given with chemoprophylaxis or have undergone radiation treatment to render them non-infectious. Recent studies have demonstrated the safety and tolerability of the whole sporozoite PfSPZ Vaccine and its potential for providing intravenous malaria protection.

• R21, a different candidate for a pre-erythrocytic vaccination, recently demonstrated promising efficacy in a pilot study conducted in Burkina Faso with infants aged 5 to 17 months.

• Other malaria vaccines possibilities, such as mRNA vaccines and transmission-blocking vaccines that target the sexual stage of the parasite growth in the mosquito, are in the research and development or testing stages.

What Are the Obstacles in the Development of a Malaria Vaccine?

The lack of a traditional market, the scarcity of developers, and the technical difficulty of creating a vaccine against a parasite have all been challenges to developing a malaria vaccine.

The complex immunological response to malaria infection is poorly understood, and malaria parasites have a complicated life cycle. The genetic complexity of malaria parasites results in thousands of possible antigens. As a result, exposure to malaria parasites does not provide lifetime immunity, unlike diseases for which there are already effective vaccinations. A person's acquired immunity only offers a limited defense against further illness, and they often still contract the parasite; malaria infection can last for months without showing any signs of disease.

What Are the Other Preventive Measures?

The preventive measures include the following:

1. ITNs (Insecticide-Treated Bed Nets):

   • These are personal defenses that have been demonstrated to lower malaria-related illness, severe disease, and mortality in endemic areas. ITNs have been shown to lower the death rate of children under the age of five from all causes by roughly 20 percent in community-wide studies in many African settings.

   • Functioning of ITNs: A barrier of protection surrounds people sleeping beneath bed nets. However, insecticide-treated bed nets offer significantly greater protection than untreated nets.

   • Mosquitoes and other insects are killed by the pesticides applied to bed nets. Fewer mosquitoes enter the house and try to feed on people inside due to the insecticides' ability to repel them. Additionally, mosquito populations and lifespans will be decreased if high community coverage is attained. When this occurs, everyone in the neighborhood is protected, whether or not they are sleeping under a bed net. More than 50 percent of the residents of a community must use an ITN to obtain these results.

2. Long-Lasting Insecticide-Treated Nets (LLINs):

   • Long-lasting insecticide-treated nets (LLINs), produced by several firms, continue to contain adequate amounts of insecticide after several times of washing for at least three years. More than 15 of these LLINs have received full or provisional approval from the WHO Pesticide Evaluation Scheme (WHOPES) for use in malaria prevention. The CDC is now testing the effectiveness and field durability of some of these and other LLINs.

   • In nations where malaria programs have achieved substantial LLIN coverage, LLINs have been linked to significant drops in malaria cases. WHO currently advises that LLINs be delivered to and used by everyone in malaria-prone areas, not just the most vulnerable populations, such as expectant mothers and young children. LLINs are typically issued through broad campaigns every three years.

3. Residual Indoor Spraying:

   • Many mosquitoes that transmit malaria are referred to as "endophilic," meaning that they rest within homes after consuming blood. Therefore, using indoor residual spraying can effectively reduce these mosquitoes (IRS).
   • Indoor Residual Spraying - As the name suggests, IRS entails applying a residual insecticide to a home's walls and other surfaces. The insecticide will kill any mosquitoes and other insects that come into touch with these surfaces for several months. IRS does not actively shield individuals from mosquito bites. Instead, if mosquitoes linger on the surface where the spray was applied, it typically kills them after they have fed. The IRS stops the spread of infection to other people as a result.

4. Intermittent Preventive Treatment of Malaria for Pregnant Women (IPTp):

   • IPTp involves giving all pregnant women a curative dosage of an efficient antimalarial medicine (now Sulfadoxine-Pyrimethamine) without determining whether they are infected with the parasite that causes malaria. Starting as early as feasible in the second trimester, IPTp should be administered at each appointment for regular prenatal care.

5. Intermittent Preventive Treatment During Infancy (IPTi):

   • Infants at risk for malaria are given a full therapeutic course of Sulfadoxine-pyrimethamine (SP) through the Expanded Program on Immunization (EPI) at intervals matching regular immunization schedules typically at ten weeks, fourteen weeks, and about nine months of age regardless of their status of malaria infection.

The decision on interventions is based on the level of malaria transmission in the area (for example, Intermittent preventive therapy for pregnant women (IPTp) is typically not advised in areas with low transmission levels).

Why Is Malaria Eradication Taking So Long?

Researchers are combating a very sophisticated parasite that specific mosquito vectors can effectively spread. Malaria has deep roots in Africa and affects some remote and underprivileged tribes. Yet, the disease has not had enough attention in the research and development field or funding to spread the available instruments, especially in nations with poor healthcare systems.

Conclusion:

Although malaria is a severe infection, there are things people can do to prevent it. Using preventative drugs and taking precautions to avoid mosquito bites can reduce the likelihood of contracting a disease. Consult the doctor several weeks before the trip if going somewhere where malaria is a widespread problem, which is very crucial at times of pregnancy.