Zyvac TCV vaccine
Zyvac TCV vaccine is given to prevent typhoid fever also known as enteric fever. This is Typhoid TCV vaccine by Zydus. This is typhoid Vi polysaccharide antigen conjugated to tetanus toxoid. This vaccine is available as single dose or multidose vial and also single dose prefilled syringe. It contains purified Vi polysaccharide of S. typhi capsular antigen conjugated to tetanus toxoid 25 mcg, sodium chloride 4.5 mg, water for injection in each 0.5 mg
How is Zyvac TCV vaccine available?
Zyvac TCV vaccine is available as ready to inject liquid form. It is available in pre filled syringe with 0.5 ml injectable single dose. It looks cloudy, the constituents become homogenous when agitated. It is packed in an opaque packet to protect it from light. The sterile single use disposable needle for injection is usually available in the packet.
How is Zyvac TCV vaccine stored?
Zyvac TCV vaccine is stored at 2-8 degree Celsius. The temperature is maintained with the help of cold chain. The temperature range should be maintained at all stages of the storage and transportation. The vaccine if frozen accidentally should be discarded and should not be used. The vaccine if passed beyond expiry date should not be used and discarded.
How is Zyvac TCV vaccine given?
Zyvac TCV vaccine is given on anterolateral aspect of thigh intramuscular injection. All the safe injection precautions should be utilized while giving injection. It should not be given subcut or intravenous as the efficacy by these routes is unknown. Those with bleeding tendency may get it subcut the clinical decision by pediatrician is needed.
At what age Zyvac TCV vaccine is given?
Zyvac TCV can be safely given to all between ages 6 months to 45 years. Two doses are given. Second dose is given 3 years of first dose. Usually first dose is given at 6 months with influenza vaccine or at 9-10 months with MMR vaccine.
What if some has missed dose of Zyvac TCV?
If someone has missed the dose of Zyvac TCVvaccine should get it earliest as possible. The decision to take vaccine should be taken after consultation with pediatrician. Those children staying in endemic area like South east Asia and Indian subcontinent should get this vaccine. Those planning to visit these regions or other endemic regions should get this vaccine atleast 3 weeks before exposure.
How does Zyvac TCV vaccine works?
Zyvac TCV vaccine contains antigens from Vi capsuler polysaccharide antigens of S. typhi capsule. When this vaccine is injected to the host all these antigens are entered into the body. Inside the host these antigens are recognized by the immune system of the host. The immune mechanism to fight against these antigens is developed. When real infection occurs the immune response is rapidly ramped up and the disease is prevented. This is active form of immunization that is host himself/herself develops the immunity by its own mechanism after vaccination. The boosters are needed to maintain the long term immunity as after many years the immunity may wane. The tetanus toxoid in the vaccine acts as conjugation protein and it helps the immune system to recognize the antigens more effectively. Tetanus toxoid increases the efficacy of the vaccine. Yet the duration this vaccine provides protection is unknown, theoretically it seems it is efficient at least till 18 years of age.
Safety of Zyvac TCV vaccine with other drugs:
- As this is killed vaccine it is safe to give the vaccine with most of the other medicines and other vaccine. It is safe if given with other vaccines like MMR, measles and pneumococcal vaccines.
- The vaccine if given with other vaccines should not be mixed in same syringe it should be given separately and at separate site.
- The vaccine is safe for immunocompromised patients and those with HIV AIDS patients.
- The safety of vaccine is not yet established in pregnancy and lactating mothers.
What are side effects after Zyvac TCV vaccine?
- Zyvac TCV vaccine is S. typhi Vi-polysaccharide antigen conjugated to tetanus toxoid.
- · Fever may come after the vaccination it may last for 3 days and usually mild to moderate grade. It can be easily controlled with paracetamol oral medicine and sponging. It can be managed at home.
- · Injection site pain and swelling may occur after vaccination. It is less as compared to DTwP vaccine. This pain can be managed with paracetamol and cold compression at injection site.
- · Irritability may come after vaccination may last for 1-3 days usually subsides by its own.
- · Headache may occur after vaccination this side effect can be easily managed with paracetamol and usually subsides by its own.
- · Lose motions and vomiting may occur in few patients after vaccination. It can be managed with Oral rehydrating solution and if needed medicine like ondansetron.
- · If patient is allergic to any component anaphylaxis reaction may occur. This is extremely rare side effect but can be life threatening. The facility at which vaccination is given should be equipped with treatment to manage anaphylaxis reaction.
To whom Zyvac TCV vaccine should not be given?
- Zyvac TCV vaccine should not be given to someone if known allergic to any of its components.
- The contraindications Of Zyvac TCV vaccine are very rare, advice of pediatrician should be considered before any conclusion.
- Those with convulsion in past is not a contraindication for this vaccination.
- Those with bleeding disorder like haemophilia should plan this vaccine after getting the dose of factor administered. Subcut route should be considered in such patients and clinical discretion of the treating pediatrician is needed.