MANILA (UPDATE)—Janssen Pharmaceuticals has started clinical trials of its COVID-19 vaccine in the Philippines, the Department of Science and Technology said Friday.
"As an update to the 3 FDA (Food and Drug Administration) approved vaccine developers to conduct clinical trials in the Philippines, Janssen Pharmaceuticals has already started with their trials," Science Undersecretary Rowena Cristina Guevara told reporters in a virtual press briefing.
Meanwhile, site preparations for the clinical trials of vaccine developers Clover and Sinovac are ongoing, she added.
Guevarra said she could not disclose the number of participants involved in the clinical trial of Janssen, the pharmaceutical arm of US health-care company Johnson & Johnson.
In a separate statement, the Department of Health clarified that the trial sites include the capital region, Calabarzon, and Western Visayas.
Science Secretary Fortunato Dela Peña earlier said the areas where the clinical trials would be conducted have a consistently high incidence of COVID-19 infections at least 2 weeks before the trials took place.
In late December, the Food and Drug Administration approved Janssen as the first pharmaceutical firm to conduct clinical trials in the country.
Janssen's experimental COVID-19 vaccine uses an adenovirus—a type of virus that causes the common cold—that has been made unable to replicate.
The adenovirus carries a gene from the coronavirus into human cells, which then produce the coronavirus spike protein, but not the coronavirus itself. This spike protein is what primes the immune system to fight off a subsequent infection by the virus.
Janssen said their vaccine candidate was 66 percent effective overall in preventing moderate to severe COVID-19, 28 days after vaccination.
The level of protection against moderate to severe COVID-19 infection was 72 percent in the United States, 66 percent in Latin America and 57 percent in South Africa, 28 days post-vaccination, it added.
The vaccine can also be stored in most standard refrigerators, making transport and distribution of the shots easier.