Immune Mechanism of Foot and Mouth Disease and Treatment of

Allergic Reaction to Vaccine

Yanxi Qiu

Malvern College Chengdu, Chengdu, Sichuan, China

Keywords:

Foot-and-Mouth Disease, Immune Mechanism, Vaccine Allergic Reactions, Rescue Measures.

Abstract: Allergic reactions caused by FMD vaccine are often encountered in the process of FMD immunization. If

not treated in time, it can cause the death of immunized animals and economic losses. This paper mainly

introduces the immune mechanism of FMD, the mechanism of allergic reaction of vaccine, the clinical

symptoms and treatment measures of allergic reaction of FMD vaccine and preventive measures, aim to

provide reference for better avoiding the occurrence of allergic reaction of FMD vaccine.

1 INTRODUCTION

Foot-and-mouth disease (FMD) is an acute, febrile,

highly contagious zoonosis caused by Foot-and-

mouth disease virus (FMDV). The genome of

FMDV is a single-stranded positive-sense RNA

with a total length of approximately 8,500

nucleotides. There are seven serotypes of FMDV,

namely O, A, C, SAT I, SAT II, SAT III and Asia I.

More than 80 subtypes, each serotype has different

antigenicity and there is no cross-immune protection

between the serotypes. Foot-and-mouth disease

(FMD) has caused significant economic losses to

animal husbandry and is the focus of quarantine and

epidemic prevention in various countries around the

world. Vaccines, available since the early 1900s,

have been the most instrumental method for

prevention and control of FMD. However, the

allergic reactions caused by vaccines should not be

ignored, which may even cause animal death.

2 IMMUNE MECHANISM OF

FOOT-AND-MOUTH DISEASE

2.1 Humoral Immunity

The immune response mediated by B cells is called

humoral immunity, and humoral immune effect is

achieved by B cells through the recognition of

antigens, activation, proliferation and finally

differentiation into plasma cells and secretion of

antibodies. Therefore, antibodies are immune

molecules that mediate humoral immune effect.

Antibodies are immune globulins secreted by B

lymphocytes after activation and have important

anti-infective effects. According to the differences

in chemical structure and antigenicity, the antibodies

of animals can be divided into five categories,

namely IgM, IgG, IgA, IgE and IgD, of which, IgG

and IgA have different subclasses. IgM is the largest

immunoglobulin molecule and consists of a

pentamer of five monomers of the same size as IgG.

IgM is the earliest antibody produced by the animal

body after the initial antigenic stimulation. Among

them, the effect of neutralizing the virus is weak, but

the ability to bind complement is strong. IgG is the

most important antibody and the most important

immunoglobulin in serum, accounting for about

75% of the total immunoglobulin, and is widely

distributed in the body. Among all

immunoglobulins, IgG has the strongest virus

neutralization and can exert immune activities such

as antibacterial, antiviral, and neutralizing viruses.

IgA is present in mucosal secretions and other

secretions, and IgA is also present in the blood, and

IgA is associated with local immunity. The site of

IgE production, similar to IgA, is produced by

plasma cells in the lamina propria of the respiratory

and digestive tracts and is present in little amount in

the serum. IgE is a cytophilic antibody that readily

binds to eosinophils and vascular endothelial cells in

skin tissue, mast cells, blood and can mediate type I

allergic reactions. IgE also has an important role in

Qiu, Y.

Immune Mechanism of Foot and Mouth Disease and Treatment of Allergic Reaction to Vaccine.

DOI: 10.5220/0012000400003625

In Proceedings of the 1st International Conference on Food Science and Biotechnology (FSB 2022), pages 5-7

ISBN: 978-989-758-638-5

 2023 by SCITEPRESS – Science and Technology Publications, Lda. Under CC license (CC BY-NC-ND 4.0)

anti-parasitic, certain fungal infections. The

secretion of IgD is rare, and its content in serum is

very low, and unstable, and easily degraded. Some

researchers believe that IgD is related to immune

memory, and some reports suggest that IgD is

related to some allergic reactions.

After animals are exposed to FMDV antigen, a

specific immune response dominated by humoral

immunity is induced and neutralizing antibodies are

produced, which mainly destroy FMDV with

neutralizing and opsonizing effects.

2.2 Cellular Immunity

The function of anti-FMD infection is mainly

related to humoral immunity, but the role of cellular

immunity and cytokines produced by immune cells

in the immune response to FMD cannot be ignored.

At present, the role and mechanism of cellular

immunity in FMD immunity are not fully

understood, and some progress has been made using

synthetic peptides and T cell technology

(

Alexandersen, 2005)

. Synthetic peptides

containing only B cell epitopes have low

immunogenicity, which may be related to MHC

(major histocompatibility complex) restriction, and

the introduction of Th cell (helper T cell) epitopes

can overcome the limitations and induce the

production of high levels of protective antibodies.

Both natural host pigs and cattle have FMDV

serotype-cross-reactive T cells, and this T cell

epitope is present on structural proteins VP1 and

VP3 (Arztl, 2011). After immunization of pigs with

FMDV inactivated antigen, the number of CD4

and

Th cells increased significantly, and lymphocytes

with immune memory could be present in the

circulatory system for at least 1 year (Ayebazibwe,

2010). In vitro, each structural protein of FMDV can

stimulate the proliferation of this cell, of which VP1

and VP3 proteins are more effective, and the

proliferative response is dependent on the antigen

dose. This shows that Th cells are involved in the

immune response to FMDV inactivated antigens.

2.3 Local Immunity

Local immunity is an extension of humoral

immunity and is mainly characterized by the

production of secretory IgA. Pharyngeal mucosal

immunity in FMD is of interest because this site is

the site of initial infection with FMDV and long-

term virus carriage.

3 MECHANISM OF ALLERGIC

REACTION TO VACCINE

Allergic reactions caused by foot-and-mouth disease

vaccine are type I allergic reactions. This reaction is

a complex process: the allergen enters the animal

body for the first time, stimulates the animal body to

produce a large amount of allergic antibody IgE, IgE

adsorbs on the mast cells of tissues and the basophil

surface of blood, so that the animal body is in a

sensitized state. When the sensitized body is re-

exposed to the same allergen, the allergic principle

binds to the IgE antibody attached to the surface of

mast cells and basophils, activates the intracellular

enzyme system, resulting in the rapid release of

various bioactive substances by cellular endocrine

granules. For example, histamine, serotonin and

anaphylatoxin, these bioactive substances can cause

inflammatory reactions, resulting in a series of

allergic reaction symptoms such as telangiectasia

and increased permeability, mucocutaneous edema,

decreased blood pressure and respiratory smooth

muscle spasm.

4 CLINICAL SYMPTOMS AND

TREATMENT OF ALLERGIC

REACTION TO

FOOT-AND-MOUTH DISEASE

VACCINE

4.1 Mild Allergic Reactions

It is a normal vaccine response and its clinical

symptoms are not obvious. Only a few pigs in the

vaccinated herd showed mild apathy and loss of

appetite (Belsham, 2011). In general, it does not

require treatment and resolves spontaneously in 1 to

2 days.

4.2 Moderate Allergic Reactions

It often occurs in groups and appears about 15

minutes after injection of the vaccine. The clinical

symptoms were very pronounced and manifested as

dyspnea, salivation, vomiting, generalized cyanosis,

unsteady standing, and intoxicated gait. Allergic

pigs are generally weak and bedridden. A small

number of pigs were also seen standing with limbs

open and sunk back (Doel, 2003). After the

occurrence of the above symptoms, epinephrine

hydrochloride or glucocorticoids should be used as

FSB 2022 - The International Conference on Food Science and Biotechnology

soon as possible for treatment, while paying

attention to keeping the environment quiet and

providing adequate drinking water.

4.3 Severe Acute Allergic Reactions

It is rare, often occurring within 15 minutes after

injection of the vaccine, and severe allergic

symptoms occur a few seconds after injection of the

vaccine. The main symptoms are: allergic animals

suddenly fall to the ground, general weakness;

dyspnea, salivation, pale conjunctiva, systemic

cyanosis, decreased body temperature; systemic

muscle tremor, confusion, ataxia, incontinence,

unresponsiveness to various stimuli; severe cases

may develop anaphylactic shock, which can cause

death if not timely rescued (Ecuru, 2010).

For severe acute allergic reactions, epinephrine

injection should be performed immediately for

treatment, and some adjuvant therapy can be taken if

necessary.

5 PREVENTIVE MEASURES

Establish a reasonable immunization schedule to

avoid simultaneous immunization with other

vaccines and minimize the occurrence of stress

reactions to foot-and-mouth disease vaccines.

Before immunization, disinfection and sterilization

of devices should be done well, and drugs such as

epinephrine or glucocorticoids should be prepared at

the same time in order to treat allergic pigs timely.

During the immunization, operate in accordance

with the specifications strictly, inject according to

the dose specified in the instructions, and postpone

the immunization for the thin, pregnant animals with

a history of allergy. After the completion of vaccine

injection, attention should be paid to observation. If

allergic reactions occurred, contact the professionals

to take treatment measures as soon as possible. In

addition, establish immunization archives timely. In

case of any death of animals due to allergic reaction,

relevant personnel shall be contacted for harmless

treatment immediately.

6 CONCLUSION

The globalization of commerce is accelerating the

spread of FMDV and presents new requirements on

the trade of animals and animal productions. But

novel vaccines against FMDV are developed slowly,

and only few available novel FMD vaccines have

been used in practice. In the development of new

vaccines, we should improve the effectiveness while

give attention to safety, minimize allergic reactions

and reduce the physical discomfort and death of

animals caused by vaccination.

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Alexandersen, S., Mowat, N., 2005. Foot-and-mouth

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Arztl, J., Juleff, N., Zhang, Z. and Rodriguez, L. L., 2011.

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Immune Mechanism of Foot and Mouth Disease and Treatment of Allergic Reaction to Vaccine