MANILA — As the dengue virus continues to infect Filipinos, mostly children, the Department of Health says it is open to the possibility of experimenting with the effectiveness of wolbachia infections among mosquitoes as a means of vector control. 

At the sidelines of the launch of the agency’s dengue prevention program, Health Secretary Teodoro Herbosa said he has already spoken to researchers from Singapore and Taiwan on the matter. 

“Ang nangyayari dito, yung wolbachia bacteria nilalagay sa lamok. So yung babaeng lamok hindi na mangangaanak. Maganda yung results. We are willing to conduct experiments as long as may mag provide ng wolbachia  bacteria,” he said. 

(What happens is mosquitoes are injected with wolbachia. So the female mosquito is no longer able to reproduce. The results are promising.)

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 HOW IT WORKS

 According to the World Mosquito Program, a non-profit organization, working with communities worldwide to prevent mosquito-borne diseases, wolbachia is a bacteria commonly found in insects.

 However, it isn’t found in the Aedes aegypti — the carriers of dengue, chikungunya and zika virus. But they can be introduced.

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 “If a male insect has wolbachia and mates with a female that doesn’t, then the eggs she lays won’t hatch. If a female has wolbachia and the male doesn’t, she would lay her normal number of eggs. They would all hatch and all offspring will carry wolbachia,” it said in an explainer. 

Because the eggs of an uninfected female mosquito, following mating with an infected male, won’t hatch, the number of aedes aegypti mosquitoes decreases.

 According to the US Center for Disease Control and Prevention, some communities have observed a significant drop in the Aedes aegypti mosquitoes.

 “Communities in Texas and California that have released mosquitoes with Wolbachia report a significant drop in the number of Ae. aegypti mosquitoes. Singapore, Thailand, Mexico, and Australia have successfully used these mosquitoes,” it said.

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 It adds there remains to data to suggest that the bacteria causes any harm to people, animals or the environment.

 NO VACCINES YET

 The health chief also reiterated that while some countries are already using dengue vaccines, there remains to be no such thing in the country. In 2023, Japanese pharmaceutical company Takeda applied for registration for its dengue vaccine before the Philippine Food and Drug Administration. 

However, it has yet to fulfill other requirements which is the reason why two years later, there is still no movement in the application.

 “May isa pang hinihingi sa kanila yung tinatawag na Risk Management Plan. Pag nasubmit nila 'yun, maaring magkaroon ng bakuna pero yung bakuna hindi natin ginagamit pag may outbreak kasi po yung bakuna,” he said.

 (They are being asked of their Risk Management Plan. Once they submit that, it will be reviewed and it may become possible for us to have a vaccine. But these vaccines are not used during outbreaks.)

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 In 2023, Takeda voluntarilty withdraw their application for a US Biologics License with the US FDA. It has also done the same with its application with Singapore’s Ministry of Health. 

The DOH has previously said that there are currently no medications that target the dengue virus, making treatment more supportive and focused on symptoms. 

This is why as the number of infections in different parts of the country rises, the agency encourages all local governments and communities to conduct clean up drives to minimize potential breeding sites of the dengue-carrying mosquitoes.