Twinrix: Hepatitis A and B combination vaccine
This vaccine is available in adult and pediatric dosages. Pediatric dosage 0.5 ml contains Hepatitis B virus surface antigen HBsAg. Adult dose is 1 ml contains Hepatitis B virus surface antigen.
|TWINRIX adult||720||20||1 ml|
|TWINRIX Junior||360||10||0.5 ml|
How is Twinrix vaccine available?
Twinrix vaccine is available as injection liquid form. It is available as 0.5 ml dose Twinrix junior or 1 ml dose Twinrix. It is available as pre filled syringe without needle. It is available in single dose form. It is packed in opaque box to protect from sunlight.
How is Twinrix vaccine stored?
Twinrix vaccine is stored at 2-8 degree Celsius. The temperature range should be maintained with the help of cold chain. The temperature range should be maintained at all levels of transport and storage. The vaccine should not be frozen. If the vaccine is frozen accidentally it should be discarded and not used for the injection.
How is Twinrix vaccine given?
This vaccine should be re-suspended before giving it. After re-suspension it looks hazy cloudy colorless in appearance.
Twinrix vaccine is given as injection on the antero lateral aspect of thigh in children with needle as intramuscular route. All the safe injection precautions should be followed while giving injection. The disposables should be discarded as per biomedical waste management protocols. The vaccine that has passed expiry should be discarded as per biomedical waste management protocol rules. For those above 19 years 1 ml dose is given. For those below 18 years 0.5 ml dose is needed.
For those who have bleeding disorder this vaccine can be administered subcutaneously and firm pressure is given after the vaccination. The vaccination should be preferably planned after getting the dose of clotting factor in haemophilliacs.
At what age Twinrix vaccine is given?
- Twinrix vaccine can be given in routine immunization at 1 year when both Hepatitis A and Hepatitis B is needed.
- It is given to all above one years as 0, 1, 6 months schedule.
- Twinrix junior can be used till age 15 years of age.
- Twinrix can be used from 1 year above.
- FDA has approved used of this vaccine above 18 years age. It has been found it is safe above 1 year age.
- In exceptional circumstances in adults, when travel is anticipated within one month or more after initiating the vaccination course, but where insufficient time is available to allow the standard 0, 1, 6 month schedule to be completed, a schedule of three intramuscular injections given at 0, 7 and 21 days may be used. When this schedule is applied, a fourth dose is recommended 12 months after the first dose.
How does Twinrix vaccine works?
Twinrix vaccine is active form of immunization but it is inactivated vaccine. It vaccine contains HBs-antigen of Hepatitis B virus in inactivated form and also Hepatitis A virus inactivated form. This antigen is obtained by the recombinant technology. When this vaccine is injected to a host the immunity of the host recognizes the antigen on Hepatitis B virus. The immunity is form against this virus and in the process the memory is also formed. When the real infection occurs the immune response is boosted against the infection and protects the person against the disease itself.
Safety with other vaccine:
Twinrix vaccine is safe with most other medicine and no drug interactions were noted. The other vaccine or other drug should not be mixed in same syringe as this vaccine.
Like other inactivated vaccines Twinrix vaccine is considered as safe in pregnant and lactating woman, but the risk benefit ratio should be evaluated by the caregiver.
Concomitant administration of typhoid, tetanus and HPV Vaccine is safe with this vaccine.
What are side effects of Twinrix vaccine?
Twinrix vaccine causes side effect that are generally milder and can be managed at home and does not need hospital admission:
- Fever is common side effect after the vaccination. It usually subsides in 1-3 days and can be managed very easily at home with medicine like paracetamol and sponging.
- Swelling and pain occurs at injection site may last for 1-3 days can be managed with paracetamol and local cold compression.
- Diarhea and loss of appetite can occur after vaccination and can be managed by oral rehydrating solution.
- Nausea and vomiting may occur after the vaccination and it can be managed by oral syp ondansetron and oral rehydrating solution.
- Abdominal pain.
- Muscular pain and joint pain.
- Headache and fatigue.
- Anaphylaxis and allergy is extremely rare side effect of the vaccine. Like other vaccines the vaccine should be administered at center where necessary personnel and drugs and equipments are available to manage if any reaction occurs.
Why this combination vaccine?
In developed countries where hygiene and drinking water quality is good Hepatitis A is rare. But when you are planning to travel to endemic countries you may have high risk of getting Hepatitis A disease if you are not immune to it.
Additionally those who were not immunized for Hepatitis B virus may find it easy to get protection from these two diseases in a single vaccine.
To whom this vaccine should not be given?
There are only few contra-indications for this vaccine:
- Those who are allergic to any of the component of this vaccine should not be given this vaccine.
- If someone has got allergic reaction at the time of the previous dose should not be given this vaccine.
- If someone is allergic to neomycin should not be given this vaccine as this vaccine contains very small amount of neomycin which can affect allergic person.