Although vaccines are effective preventive measures against many diseases, they remain a major scientific challenge in reducing deaths from infectious diseases such as tuberculosis or AIDS, and vector-borne diseases such as malaria, mosquitoes, and Crimean-Congo hemorrhagic fever or Lyme disease, a tick-borne disease.
Andrei Daniel Michalka, Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Romania.
The latter are considered the second largest carrier of human diseases after mosquitoes and the most common ectoparasite of domestic and wild animals.
Ticks carry pathogens such as bacteria (Lyme disease, Mediterranean spotted fever and anaplasmosis), viruses (tick-borne encephalitis and Omsk hemorrhagic fever) and parasites (babesiosis).
They can also cause allergic reactions to their bites and to the consumption of animal products such as red meat, in a condition called Alpha-Gala syndrome, which is underdiagnosed and widespread worldwide.
The challenge is to keep them at bay.
Some recommendations include wearing long-sleeved shoes when entering the field, then checking the body for bites and removing them with fine tweezers where they attach to the skin, without squeezing to prevent their contents from entering the body.
However, ticks are difficult to control and the most common measures are based on the use of chemical acaricides, which have a negative impact on the environment.
It should be added that its abuse has led to the emergence of ticks resistant to these toxic chemicals.
An alternative are natural acaricides, which can be obtained from extracts of plants with repellent properties, such as rosemary, garlic or mint.
Andrei Daniel Mihalka, Department of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca, Romania.
Studying traditional methods of different cultures to repel these parasites with plants has taught us how some of them can help to repel them or make them leave dangerous places, such as the ear canal.
However, against this backdrop, vaccines represent the most effective, safe, economically viable and environmentally sustainable intervention. As a result, this will affect their feeding and reproduction and thus lead to a reduction in their population over time.
For this reason, vaccines are being developed and applied to both domestic and wild animal species that play an important role in maintaining tick populations.
Evolution of vaccines
From the classic 3I (isolate-inactivate-inoculate, isolate-inactivate-administer) scheme of the late 18th century, today we have advanced to genetic engineering and biotechnology, reverse and computational vaccinology, vaccinomics and quantum vaccinomics, and personalized vaccinology with new formulations and delivery platforms.
In this scenario, vaccine evolution was driven by multiple challenges, such as creating an effective formula against multiple species of these parasites or the impact of genetic diversity of tick strains on vaccine effectiveness.
Tick vaccine antigens evolved from protein extracts of internal organs into recombinant proteins and chimeras created using quantum vaccinomics.
Future directions will advance these areas along with other emerging technologies such as multiomics, artificial intelligence and big data, mRNA vaccines and probiotics.
Read more: These are mRNA vaccines that will protect us from various deadly diseases
Combining vaccines with other measures in collaboration with regions with high incidence of ticks and transmitted diseases is also important for a tailored approach to vaccine development.
Two sides of the coin
Thus, as our Health and Biotechnology Group at the Hunting Resources Research Institute (IREC-CSIC) has just demonstrated, developing personalized vaccines to combat ticks in countries with the highest incidence of the disease will contribute to the control of these diseases and their impact on society.
Andrei Daniel Mihalka, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Romania.
But we must consider both sides of the coin. Ticks also have properties that we should be aware of. They play an important role in biodiversity and serve as food for some species of animals, and they also help control them naturally.
These organisms have evolved to produce molecules with anti-tumor properties and to be able to create living tissue for surgical interventions.
Thus, we can control ticks, but not eradicate them from all habitats, as they are important for the protection of biodiversity and the development of biomedicine.