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Frequently Asked Questions (FAQs)



 Is the STVac vaccine safe?

STVac vaccine is an intranasal spray vaccine developed by Universiti Putra Malaysia (UPM) to protect goats and sheep against the respiratory disease known as mannheimiosis (previously known as pasteurellosis). The vaccine has undergone laboratory and field trials and is found to be effective and safe.


What are the ingredients in the STVac vaccine?

STVac is a recombinant inactivated bacterial vaccine produced in E. coli (as production host) that carries specific antigens from the outer membrane protein of M. haemolytica bacterium. The protein of interest is expressed by the E. coli, and the E. coli is known as recombinant cells. These cells are grown, harvested, inactivated and prepared as vaccines.


Why should my goats and sheep get vaccinated against Mannheimiosis?

Mannheimiosis is a common respiratory disease found in sheep and goats worldwide, leading to between 30% and 40% death in a goat or sheep population. Following vaccination, the rate of mortality caused by Mannheimiosis could be reduced to an average of 2%. Therefore, vaccinating goats and sheep could significantly increase the survival rate of animals and eventually, the income of farmers.  


Can the STVac vaccine be utilized for different types of strains?

Yes. STVac vaccine is currently the only intranasal spray vaccine against mannheimiosis that can stimulate both local and systemic immunities and provides cross-protection against infection by M. haemolytica A2, A7 and A9 strains. 


Is it harmful if the STVac vaccine is accidentally consumed by a human?

Veterinary vaccines are intended only for use in animals and are not tested for safety in humans. Accidental consumption by humans would not cause serious harm.

Getting The STVac Vaccine


 Do the animals need a booster? How many doses of STVac vaccine should they get?

The animals should get the booster dose as recommended. Failure to provide the booster would risk infection among some of the animals in the population. Nevertheless, these animals should get the booster dose as soon as possible.  


If the animals didn’t get the second booster dose of STVac vaccine within the recommended time, what should be done?

The animals should get the booster dose as recommended. Failure to provide the booster would risk infection among some of the animals in the population. Nevertheless, these animals should get the booster dose as soon as possible.  


How long does protection from Mannheimiosis disease last?

The protection lasted between 3 and 4 months. To effectively protect goats and sheep against Mannheimiosis, vaccination should be done prior to monsoon, winter or summer season, i.e. once every 6 months.


How many goats or sheep can be vaccinated for 250 ml or 500 ml solution STVac vaccine?

One ml of the vaccine is required for each goat and sheep per vaccination. Therefore, a 250 ml bottle can be used for 250 animals, while the 500 ml bottle can be used for 500 animals.


If the dosage of the vaccination exceeds more than 1 dose, what will happen?

Exceeding the recommended dose is wasteful. However, exceeding the dose limit will not cause any adverse effects to the animals.


How long does the goat or sheep need to wait after getting another vaccine, before getting a STVac vaccine?

The animals can get vaccinated with the STVac vaccine at any time after getting other vaccines. This is because the mechanism of the STVac vaccine is different from other systemic vaccines and will not complicate the effectiveness of both vaccines.


If the animals already had Mannheimiosis and recovered, are they covered by natural immunity, or do they still need to get the STVac vaccine?

Animals recovered from mannheimiosis develop natural immunity but this lasts for a period of 6 months. Therefore, they still need booster(s) using the STVac vaccine. 


Can the animals get vaccinated against Mannheimiosis disease while currently sick with the disease?

The concept of vaccination is to prevent infection, and STVac is not intended for treatment of Mannheimiosis in infected animals. Providing STVac vaccination to infected animals is of little help.


Do we need trained personnel or veterinarian for the vaccination of the goats and sheep?

STVac is an intranasal spray vaccine that is easy to administer. Vaccination can be done by the farmers themselves, without the presence of trained personnel.

Getting The STVac Vaccine


Do the animals need to avoid close contact with the unvaccinated animals after they are vaccinated?

No restriction or isolation is needed between vaccinated and unvaccinated animals. 


What is the level of effectiveness of the STVac vaccine?

STVac vaccine reduces deaths by mannheimiosis to 2%-5% compared to 30%-40% deaths among unvaccinated animals. Thus, the STVac vaccine provides between 95% and 98% survival rates against Mannheimiosis.


How long for the vaccine to affect the goats and sheep?

Based on the serum antibody level of the vaccinated animals, the STVac vaccine is effective as early as 1 week after the initial vaccination, and following the booster dose, the effectiveness lasted between 3 and 4 months.


What is the withdrawal period for the vaccination?

The withdrawal period is usually a concern for drugs and antibiotics. Since the STVac vaccine is a biologic, there is no issue with the withdrawal period. However, our study revealed that the vaccine is eliminated from the body within 2 weeks, which is an acceptable time period to stimulate local and systemic immunities.


What is the storage condition of the vaccine?

The vaccine can be stored at ambient temperature (25°C to 30°C) and is stable for a period of one year. Leftover of the vaccine must be stored between 2°C and 8°C and must be used within 2 weeks.

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