Understanding Rotavirus Vaccine - Indication, Pharmacology, Warnings, and Precautions

Overview:

The Rotavirus vaccine is an effective and promising preventative approach to Rotavirus infection. On third April 2008, the supreme drug regulatory authority of the United States, the Food and Drug Administration (FDA), authorized and licensed the Rotavirus vaccine. Later, many countries, including India, incorporated the Rotavirus vaccine as part of the Universal Immunization Program (UIP). The Rotavirus vaccine offers an appreciable defense against infection triggered by Rotavirus. Rotavirus infections can typically pose health risks in babies, precipitating gastrointestinal issues. Rotavirus vaccines are made available under various brand names and licensed by different pharmaceutical companies.

Vaccine Group:

Rotavirus vaccines are categorized under live attenuated vaccines. The live and viable viruses are incorporated into vaccine formulation. However, the viruses are treated so that they cannot bring about active infection in the body even after introduction. The presence of antigenic components in the vaccine allows the body to work against it by producing the specific counter agent (antibody).

Available Doses and Dosage Forms:

Rotavirus vaccines are generally formulated in liquid form. The individual dose and dose frequency may differ with each Rotavirus vaccine brand. Most Rotavirus vaccines are triple-dosed, while double-dose vaccines are also available.

For Patients:

What Is Rotavirus Infection?

Rotavirus infection collectively refers to all forms of infections triggered by Rotavirus. Rotavirus specifically infects the younger age groups, typically babies and small kids. These infections are catchy and transmitted from an infected person to a healthy body. Stomach pain, vomiting, stomach upset, diarrhea, fever, weakness, and tiredness are the frequently encountered manifestations of Rotavirus infections. Obvious manifestations of Rotavirus infection are precipitated two days after the virus gains access to the body. The intense diarrhea associated with Rotavirus infection makes the child prone to dehydration. The watery diarrhea typically persists for a week and can potentially endanger the child’s life if not given proper medical attention. Antibiotic therapies are ineffective for these infections as a virus triggers the condition. Rotavirus vaccines are a widely accepted preventive strategy to check the development of rotavirus infection.

How Does Rotavirus Vaccine Work?

Rotavirus vaccines work by pre-activating the body’s immune system against the antigenic component of Rotavirus. The weakened virus particles incorporated into the vaccine formulation trigger an immune-mediated response in the body. Upon introducing the Rotavirus vaccine, specific immune cells identify the pathogenic component. Following this, the antibody for that particular virus will be generated. So upon further encounter with Rotavirus, the immune cells immediately recognize the pathogen, facilitating a quicker response and viral eradication.

What Is the Dosage of Rotavirus Vaccine?

Two milliliters (ml) is the generally advised Rotavirus vaccine dose. The initial dose needs to be given within the age range of six to 12 weeks. An average of four to ten weeks gap must be maintained between doses. The final third dose needs to be administered before the child reaches the age of 32 weeks.

How Effective Is the Rotavirus Vaccine?

The effectiveness and potency of the Rotavirus vaccine have been evaluated through clinical trials and studies. The studies demonstrated that the Rotavirus vaccine effectiveness ranges between 98 to 74 percent. However, the effectiveness tends to elicit slight variations by the vaccine brands. There are reports of rotavirus infections even in vaccinated groups of the population. Getting the Rotavirus vaccine at a later stage (over eight months of age) also compromises the vaccine’s effectiveness and range of protection. Hence, it is not recommended.

What Are the Things to Inform the Doctor Before Taking the Vaccine?

Before getting the Rotavirus vaccine, it is important to have a thorough discussion with the doctors.

• Suppose the baby has had a previous allergic or hyperreactive encounter with the initial Rotavirus vaccine dose. In that case, the doctor should be aware before proceeding with subsequent vaccine doses. Allergic reactions to even other vaccine forms should also be taken into consideration.

• If the child has any immune-mediated conditions or other underlying ailments, it is imperative to inform the doctor before Rotavirus vaccine ingestion. Depleted immune status can impact the effectiveness and working mechanism of the Rotavirus vaccine. Similarly, if the child is detected with gut blockage, that should be drawn to the doctor's attention beforehand.

• The doctor should be made aware of the child’s age. Ingesting the Rotavirus vaccine in children over 32 weeks is generally not preferred.

How Is Rotavirus Vaccine Administered?

Rotavirus vaccine is available in ready-to-use tube-shaped containers. Each vaccine dose container comes with its protective pouch. The pouch can be ripped off, and the dispensing tube can be taken out of the pouch. The dispensing tube is secured with a cap, which can be split apart by turning it clockwise, followed by an anticlockwise motion. Once the cap breaks off, the dispensing tube becomes ready for vaccine delivery. Being an oral vaccine, the entire dispensing tube’s content is expressed in the child’s mouth. Care should be employed to keep the dispensing tip towards the inner cheek so that the vaccine easily goes in. It also reduces the scope for spitting of the vaccine and incomplete vaccine dose delivery.

What Are the Side Effects of Rotavirus Vaccine?

Like other vaccines and medicines, the Rotavirus vaccine does bring about certain adverse reactions following oral administration. Some of the frequently reported side effects of the Rotavirus vaccine include the following:

• Irritability.

• Restlessness.

• Diarrhea.

• Blocked gut.

• Fever.

• Vomiting.

• Muscle pain.

• Headache.

• Ear pain.

• Stuffy nose.

• Stomach pain.

At times, the Rotavirus vaccine can bring in severe hypersensitivity reactions in the child’s body, which can be grave and alarming. Severe allergic responses mandate immediate medical assistance to safeguard the child’s life.

Dietary Considerations:

No specific dietary considerations need to be followed for Rotavirus vaccine intake. The presence or absence of feeding does not elicit an appreciable influence on the actions of the Rotavirus vaccine.

Missed Dose:

The Rotavirus vaccine course encompasses two or three doses spaced at specific intervals. If the correct date for the subsequent dose is missed, it can be ingested once the overlooked vaccine dose is recalled, provided the child is within the specified age limit. Children over 32 weeks of age are generally not indicated for Rotavirus vaccine. During Rotavirus vaccine administration, the vaccine solution's intended dose may not be achieved due to partial delivery of the vaccine solution. Similarly, the child may sometimes spit out some amount of the vaccine solution. In both these instances, no attempt should be made to administer an extra dose of the Rotavirus vaccine to counterbalance the deficient vaccine dose.

Overdose:

Overdose of the Rotavirus vaccine can develop following ingesting an extra vaccine solution. There is only limited information concerning the Rotavirus vaccine overdose. Upon overdose ingestion, there was a dramatic peaking of adverse reactions. However, no new side effects have been reported in association with overdose.

Storage:

Rotavirus vaccine solutions are marketed in single-use dispensable tubes. The ideal temperature range for Rotavirus vaccine storage is two to eight degrees Celsius (36 to 46 degrees Fahrenheit). It is recommended to keep the vaccine solution away from direct sunlight exposure. Before vaccine ingestion, ensure that the vaccine is within the usage period.

For Doctors:

Indication:

The Rotavirus vaccine is indicated for babies aged six weeks to 32 weeks to extend defense against rotavirus infections.

Dose:

Two milliliters is the standard Rotavirus vaccine that is employed. Based on the vaccine brand, there are two or three individual vaccine doses in a Rotavirus vaccine course. All three doses must be covered before the baby attains 32 weeks. The initial dose can be administered right after the child attains six weeks of age. The initial dose needs to be administered before the age of 12 weeks. Following each dose, there should be a gap of at least four weeks, but it should not extend for more than ten weeks.

Dosing Considerations:

No specific dosing considerations or alterations are advised unless the concerned doctor suggests.

What Are the Pharmacological Aspects of Rotavirus Vaccine?

1. Mechanism of Action: Weakened rotavirus forms are employed in the Rotavirus vaccine. Attenuation depletes the disease-causing potentiality of the virus. However, the presence of antigenic components triggers the body’s immune system. Upon oral ingestion, the antigen-presenting cells immediately pick up the antigenic component and evoke the corresponding antibody production. In addition, it also brings about T-cell activation, which keeps the memory of the virus. In this way, the Rotavirus vaccine primes and pro-activates the immune system for a swift response upon subsequent encounter with the Rotavirus vaccine.

2. Pharmacodynamics: The Rotavirus vaccine brings about immune memory by keeping remembrance of the antigenic counterpart of rotavirus. Furthermore, once introduced into the body, the Rotavirus vaccine interacts with the stomach cells, evoking natural immune-mediated reactions and eventually precipitating immunoglobulin (Ig A) production.

3. Pharmacokinetics: The Rotavirus vaccines do not possess a typical pharmacokinetic profile like other medications or drugs for curing specific ailments. However, the Rotavirus vaccine underwent certain alterations and processing in the human body. Rotavirus vaccines are available for the oral route, where the vaccine is introduced into the body via the mouth. From the mouth, the vaccine formulation gains access to the intestinal mucosa, where it gets absorbed. Following absorption, the vaccine triggers the immune system, eventually producing antibodies. The antibody, along with the help of other immunological components, like macrophages, eliminates and stamps out the viral particles. The viral remnants are often expelled from the body through fecal.

Toxicity:

Rotavirus vaccine toxicity develops due to intake of more than the stipulated dose of Rotavirus vaccine. The reported toxicity issues concerning the Rotavirus vaccine encompass diarrhea, uneasiness, intussusception, general weakness, and muscle pain. The toxicology profile of the Rotavirus vaccine has not been explored much, limiting relevant information concerning how the Rotavirus vaccine interferes with one’s reproductive potential. The carcinogenic and mutagenic involvement of the Rotavirus vaccine is still under discussion, and no conclusive results have been obtained to date.

Clinical Studies:

Case-control studies have been conducted in 12 countries spanning four continents. These studies were randomized to curb bias. The studies demonstrated that the Rotavirus vaccine offers extended protection and shielding against rotavirus gastroenteritis when administered within the specified age limit. Along with the vaccine potency, the safety aspects of the Rotavirus vaccine have also been studied. There were no reports of life-threatening events in the study subjects throughout the study period.

What Are the Contraindications of Rotavirus Vaccine?

• Babies with flagged allergic or hypersensitivity reactions to the initial Rotavirus vaccine dose or any vaccine components should not continue with the course.

• Babies diagnosed with intussusception should refrain from getting the Rotavirus vaccine, which is identified to be an absolute contraindication.

• Severe combined immunodeficiency disease (SCID) is another disease condition that obviates the administration of the rotavirus vaccine. Persistent release of viral particles and intensive diarrhea has been reported when babies with SCID are administered with the Rotavirus vaccine.

Warnings and Precautions:

• Gastrointestinal Disorders: The safety profile of the Rotavirus vaccine in babies diagnosed with gastrointestinal ailments is not proven. Therefore, it is generally not advised for babies with gastric issues. However, if advised by a doctor considering the susceptibility of the Rotavirus infection, exercise caution and attention to check for unexpected complications.

• Allergy: As the Rotavirus vaccine carries the risk of hypersensitivity, ensure access to immediate medical support while getting the vaccine so that prompt medical care can be sought during immediate reactions.

• Compromised Immunity: Babies with depleted immune status or other medical conditions that deteriorate the immune conditions need to be thoroughly evaluated before vaccine administration. The safety profile of the Rotavirus vaccine for such babies is not scientifically proven. Human immunodeficiency virus infection, leukemia, hypogammaglobulinemia, lymphoma, and neoplastic lymphatic lesions are some medical conditions impairing the body’s immune functions.

• Virus Shedding: There are reports of virus shedding in the initial few days post-vaccination. Virus shedding through stool can extend up to 15 days post-vaccine ingestion. Therefore, before advising the Rotavirus vaccine, ensure the baby’s close contact list does not include anybody with impaired immune status.

• Intussusception: Certain studies have demonstrated that Rotavirus vaccine ingestion can make the child vulnerable to intussusception.

• Febrile Conditions: Mild forms of febrile illness often necessitate holding back on Rotavirus vaccine ingestion. However, the doctor analyzes the need for vaccine ingestion and determines the risks and benefits associated with Rotavirus vaccine ingestion in that particular case.

• Incomplete Vaccine Course: Rotavirus vaccine fails to offer maximum effectiveness when the vaccine course is partially stopped or incomplete.

What Are the Drug Interactions of Rotavirus Vaccine?

The Rotavirus vaccine does not elicit obvious interactions with other vaccine formulations, including the Poliovirus vaccine, Tetanus toxoid, Pneumococcal conjugate vaccine, and Hepatitis B vaccine. However, it tends to interfere with certain therapeutic medications, like corticosteroids, antimetabolites, alkylating agents, and cytotoxic drugs, when administered simultaneously. Concomitant ingestion of medicines belonging to these drug classes with the Rotavirus vaccine may dramatically depreciate the vaccine’s potency.

Specific Considerations:

• Rotavirus Vaccine During Pregnancy and Lactation: Rotavirus vaccines are indicated for only a specific age group. The vaccine must be ingested before the age of 32 weeks; therefore, it is not advised for expectant or lactating women. No studies have been conducted on these specific populations.

• Rotavirus Vaccine in the Pediatric Population: Though specifically designed for pediatric use, it is restricted to babies between six and 32 weeks of age. Babies over 32 weeks and under six weeks should not get the Rotavirus vaccine.