When a person is 18 years of age or older, influenza vaccination is used to actively immunise against influenza disease caused by influenza virus subtypes A and type B.

• • All individuals older than 6 months who do not otherwise have contraindications to the vaccine are advised to have a routine annual vaccination with seasonal influenza vaccine, according to the Advisory Committee on Immunization Practices (ACIP).

  • Additionally, ACIP does not express a preference for a particular influenza vaccination product and instead advises using any product appropriate for the user's age and risk factors.

  • Recombinant influenza vaccine can also be given to anyone older than 18 years old (RIV).

  • RIV is one of several products that are available for specific patient populations. e.g:

    • The trivalent inactivated influenza vaccination (IIV3) or the quadrivalent inactivated influenza vaccine are both options for people under the age of six months (IIV4).

    • For the influenza season of 2018–2019, there is also the live attenuated influenza vaccination (LAIV4)

• Target populations for vaccination (those at increased risk of complications from influenza illness and their close contacts) include the following when vaccine supply is restricted (Only use RIV if appropriate).

  • Children and infants 6 - 59 months of age

  • Persons ≥50 years of age

  • Nursing home residents and other long-term care facilities

  • Reye syndrome can occur after influenza in infants, kids, and teenagers (6 months to 18 years of age) using long-term aspirin or salicylate therapy.

  • Patients with hepatic, renal, neurologic, hematologic, or metabolic problems as well as chronic lung disorders (including asthma) or cardiovascular system abnormalities (other than isolated hypertension) (including diabetes mellitus)

  • individuals with immunosuppression from any source (including immunosuppression caused by medications or HIV)

  • Reye syndrome following influenza may occur in infants, children, and teenagers (6 months to 18 years of age) on long-term aspirin or salicylate therapy.

  • pregnant women or those who want to get pregnant during the flu season

  • Health care professionals, including students pursuing these fields, who interact with patients

  • household members, including kids, and those who look after newborns, infants, kids under 5, especially those under six months old, as well as people under 50

  • household members, especially youngsters, and those who care for people who have medical conditions that increase their risk of developing serious consequences from an influenza infection

  • American Indians/Alaska Natives

  • Morbidly obese (BMI ≥40)

Recombinant hemagglutinin influenza vaccine Dose in Adults

• It's crucial to note that the time and length of influenza seasons change from year to year.

• Generally speaking, immunisation should start as soon as the vaccine is made available (and, ideally, by the end of October) and before the initiation of influenza activity in the community.

• As long as vaccine is available, vaccination should be continued throughout the influenza season.

• For those who have previously received all of the recommended vaccinations, the CDC does not advise revaccination later in the season.

Dose in the Immunization:

• 0.5 mL/dose IM
• 1 per season is given

Recombinant hemagglutinin influenza vaccine Dose in Childrens

• Generally speaking, immunisation should start as soon as the vaccine is made available (and, ideally, by the end of October) and before the initiation of influenza activity in the community.

• As long as vaccine is available, vaccination should be continued throughout the influenza season.

Dose in the Immunization:

• Adolescents ≥18 years:
  • 0.5 mL per dose IM is given as a single dose per season.

Pregnancy Risk Factor: C

• Information regarding the use of the recombinant influenza vaccine (RIV) during pregnancy cannot be made available.

• Negative fetal outcomes are often associated with maternal influenza.

• Women who are expecting or just gave birth have an increased risk of influenza-related complications.

• All females who become pregnant during influenza season should be vaccinated with an inactivated influenza vaccination. This vaccine can be administered at any time during pregnancy.

• All females who become pregnant or are at risk of becoming pregnant during influenza season can be vaccinated with the recommended inactivated vaccine.

• Pregnant women should follow the same preventative measures that non-pregnant people use to lower their risk of contracting the flu or other respiratory illnesses.

• Women who are pregnant or who will become pregnant during the flu season should concentrate on getting the immunisation if vaccine supplies are restricted. Mothers of newborns, caretakers, and contact parents of kids under 5 are included in this.

Recombinant hemagglutinin influenza vaccine use during breastfeeding:

• If the vaccination is present in breast milk is unknown.
• The manufacturer advises considering the hazards of newborn exposure, the advantages of breastfeeding, and the advantages of receiving a vaccination before deciding whether to continue breastfeeding after immunisation.
• Safety of breastfeeding is not affected by recombinant vaccines.
• Breastfeeding infants need to be vaccinated according to the recommended schedules
• If vaccine supplies are limited, the emphasis should be placed on the delivery of the vaccine to pregnant women or those who will become pregnant during flu season.
• This includes mothers of infants, caregivers, and contact parents of children under 5 years.
• Breastfeeding women who have not received the influenza vaccine during pregnancy can be vaccinated postpartum

Recombinant hemagglutinin influenza vaccine Dose in Kidney Disease:

There are no dosage adjustments provided in the manufacturer’s labeling.

Recombinant hemagglutinin influenza vaccine Dose in Liver Disease:

• There are no dosage adjustments given in the manufacturer’s labeling.

Common Side Effects of Recombinant hemagglutinin influenza vaccine Include:

• Central Nervous System:

  • Headache
  • Fatigue

• Local:

  • Pain At Injection Site

• Neuromuscular & Skeletal:

  • Myalgia

Less Common Side Effects of Recombinant hemagglutinin influenza vaccine Include:

• Central Nervous System:

  • Chills

• Gastrointestinal:

  • Nausea

• Local:

  • Injection Site Reactions

• Neuromuscular & Skeletal:

  • Arthralgia

• Respiratory:

  • Cough
  • Nasal Congestion
  • Nasopharyngitis
  • Pharyngolaryngeal Pain
  • Rhinorrhea
  • Upper Respiratory Tract Infection

Contraindication to Recombinant hemagglutinin influenza vaccine Include:

• Anaphylaxis or severe allergic reaction to any vaccine component

Warnings and precautions

• Anaphylactoid reactions and hypersensitivity reactions

  • During vaccine administration, immediate treatment should be given (including epinephrine 1, mg/mL) to treat anaphylactoid or hypersensitivity reactions.

• Syncope

  • Injectable vaccines can cause syncope and may result in severe secondary injuries (eg skull fracture or cerebral hemorhage).
  • It is most commonly reported in adolescents and young adults within 15 minutes of vaccination.
  • If syncope occurs, procedures should be prepared to prevent injuries from falling.

• Acute illness:

  • The severity of symptoms and the etiology determine whether or not vaccination should be administered.
  • Administration of medication should be delayed in patients with severe or moderate acute illnesses (fever included).
  • In cases of minor acute infections, the vaccine should not be postponed.

• Bleeding disorders:

  • Patients with bleeding disorders, including thrombocytopenia, should be cautious.
  • IM administration can cause bleeding/hematoma.
  • If the patient is on antihemophilic therapy or another similar therapy, IM injections can be scheduled within a few hours.

• Guillain-Barre syndrome:

  • Guillain Barre syndrome (GBS) patients need to exercise caution.
  • Patients with a history of GBS have a higher risk of developing the condition than those without.
  • The ACIP advises against vaccination for individuals who have had GBS in the past, are at low risk of developing severe influenza complications, and have known GBS symptoms within six weeks of receiving a previous vaccination. Additionally, these patients need to be advised that they can benefit from receiving influenza antiviral chemotherapy.
  • The advantages of immunisation may exceed the risks for people with a history of GBS who are more likely to experience serious complications from influenza.
  • Influenza infection itself can cause Guillain-Barre syndrome
  • Recent research has shown that GBS risk is less with vaccines than with influenza.

Monitor:

• Monitor for anaphylaxis and syncope for 15 minutes after administration.
• Maintain the patient in a supine or Trendelenburg position to reestablish adequate cerebral perfusion if syncope occurs.

How to administer Recombinant hemagglutinin influenza vaccine?

For Intramuscular administration only.

• Before attaching the needle, gently invert the syringe.

• Before administering, check for impurities and discolouration.

• If after shaking, there are any visible particles or discoloration in the solution, do not use.

• Adults should receive a deltoid vaccination.

• Avoid injecting in the gluteal area or other places where there may be a significant nerve trunk.

• Do not combine with other injections or immunizations.

• For every injection, a different set of needles and syringes is utilised.

• Patients should receive a vaccination while seated or lying down to prevent injuries linked to syncope.

•  For patients at risk of bleeding following intramuscular injection, the vaccine should be given by an expert familiar with the patients bleeding risk.

• The intramuscular immunisation might be scheduled soon after the patient takes antihemophilic or any similar therapy.

• For the immunisation, a fine needle (23 gauge or smaller) is used, and for at least 2 minutes, the location is subjected to firm pressure (without rubbing).

• Instructions regarding the possibility of a hematoma following the injection should be communicated to the patient.

• Patients receiving anticoagulant therapy are handled the same as those with clotting factor abnormalities in terms of bleeding concerns.

Mechanism of action of Recombinant hemagglutinin influenza vaccine:

• It induces specific antibody production, which promotes immunity against seasonal influenza virus.
• It is forbidden to use preparations from the previous seasons.

The beginning of action

• Almost all adults are protected against antibodies within two weeks after vaccination.

Time

• Vaccine effectiveness can decrease at different rates depending on the virus subtypes and patient age.

International Brands of Recombinant hemagglutinin influenza vaccine:

• Flublok Quadrivalent
• Flublok

Influenza vaccine in Pakistan:

Fluvarix - GSK Influvac - Abbott Quimi-Hib - Macter Vaxigrip - Sanofi-aventis