Q Will the new dengue vaccine help to protect me against all the different strains of dengue?
A Yes, but to a different extent depending on the strain. Against Den-1 and Den-2, which are the more common dengue strains in Singapore, vaccine efficacy is 50 per cent and 40 per cent respectively. The figures are 75 per cent and 77 per cent for Den-3 and Den-4.
Q Why is the vaccine not recommended for children under 12?
A In clinical trials, children aged between nine and 11 were vaccinated against dengue.
Those who still contracted dengue infections afterwards had a 30 per cent higher risk of hospitalisation. Also, the children had three times the risk of developing severe dengue. These effects were not observed in those aged 12 and above. In fact, the risk of hospitalisation was reduced for the older age group after vaccination.
Q Why is vaccination not recommended for those aged above 45?
A A study conducted in Australia showed that people aged 46 to 60 had a very low antibody response to the vaccine, meaning that it is likely to be less effective at protecting people in this age group from dengue.
Q How much more effective is the vaccine in people who have had dengue before?
A If you have had dengue, the vaccine's efficacy is 81 per cent. However, if you have not been infected with dengue before, this figure is only 38 per cent.
Q What are the side effects of the dengue vaccine, and how long do they last?
A They include soreness at the injection site, a low-grade fever, headaches and muscle aches. These are similar to the side effects of other approved vaccines. The vaccine, which is administered in three doses over a year, is still being studied.
Results so far have shown that it is effective up to four years from the administration of the last dose.
Q When will Dengvaxia be commercially available, and how much will it cost?
A The Health Sciences Authority has said the vaccine will be made available in several months' time, although it did not give a specific timeline.
The maker, Sanofi Pasteur, has not disclosed how much it will cost. Its head of global medical affairs, Dr Su-Peing Ng, has said it will make the vaccine "as commercially accessible as possible".
Q Will the vaccine be subsidised when it becomes commercially available?
A No. The Health Ministry has said the vaccine will not be part of a national vaccination programme because it would not be a "clinically and cost-effective means to tackling dengue infection in Singapore". This means that the vaccine will not be subsidised, and you cannot use Medisave to pay for it.