THE NEED FOR A MULTIPRONGED APPROACH
To properly manage chikungunya epidemics in Singapore, a deliberate and multipronged approach is essential. Ongoing medical studies, in addition to the support of international collaboration between governments, educational institutions, and medical companies, is one of the key components of this approach.
Death rates have significantly decreased because of early monitoring and access to appropriate medical care for mosquito. However, there are no currently available commercially that are especially designed to treat mosquito. It can be challenging to keep in mind the interest of pharmaceutical companies in developing such drugs to treat and prevent severe infections, which are less attractive than those for persistent diseases.
Additionally, the defensive complexity of the mosquito disease makes it challenging to develop a safe and effective vaccination. There are four distinct dengue serotypes, and each of them co-circulates directly. Immunity to a person who is infected by a particular serotype increases, but this immunity does occasionally worsen a following infection brought on by a different serotype.
A vaccine that protects all four serotypes would be a match change.
The presence of a vaccine that is effective against the most prevalent circulating mosquito serotypes, does not increase following infection, and can be given to a wide age range, including older people, would be very helpful in reducing the burden of mosquito in Singapore.
Already, Singapore has just one licensed mosquito vaccine, Dengvaxia. Only those with previous infections between the ages of 12 and 45 should bevaccinated. As quite, its use geographically so far has been limited.
Sanofi, but, recently announced that they will abandon creation of Dengvaxia due to a lack of demand worldwide.
Qdenga is another vaccine that has just been introduced in a number of nations. It has been approved in countries including Indonesia, Thailand, Vietnam and conditional acceptance in Malaysia for employ independently of prior infection.
Four and a half years after giving Qdenga, a study found that it was about 84 % effective in reducing hospitalization and 61 % effective in preventing symptomatic dengue cases.
However, for countries with low to moderate dengue transmission, including Singapore ( Singapore is considered to have a low dengue transmission ), the World Health Organization’s position paper in May 2024 currently does not recommend Qdenga’s inclusion into national vaccination programmes.
Qdenga does not appear to protect against serogroup 3 and it is questionable if it protects against serogroup 4. Although it has a high efficacy against serotype 2, the predominate serotype in Singapore, it does not seem to protect against serotype 3.
Following a review by the Health Sciences Authority based on first submitted clinical data, the company in Singapore has even withdrawn its software to record Qdenga here.
A second dengue vaccination, TV003, has just completed clinical trials in Brazil with promising benefits. Longer-term follow-up information is pending.