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Avigan, promising COVID-19 remedy, is not a vaccine

Source: Fujifilm website

Avigan is not a vaccine, but an existing anti-flu drug being tested to see if it can treat COVID-19, an infectious disease caused by the novel coronavirus SARS-CoV-2.

Cabinet Secretary Karlo Nograles mistakenly classified the antiviral medication Avigan (generic name: favipiravir) among “potential vaccines” against the coronavirus disease in his April 15 briefing.

Reporting the discussion between President Rodrigo Duterte and Japan’s Prime Minister Shinzo Abe at the special virtual summit of the Association of Southeast Nations and its dialogue partners Japan, China and South Korea on Tuesday, Nograles said:

The President had an exchange with Japanese Prime Minister Abe regarding this drug, and during the meeting reiterated that the Philippines is ready to participate in clinical trials of potential vaccines like Avigan.

He said Abe informed the president about 50 countries are interested in studying the drug further, and “gave special mention to President Duterte in this regard.”

Avigan is not a vaccine: It does not contain the virus (SARS-CoV-2) that causes the disease (COVID-19) as vaccines do.

A vaccine is made from very small amounts of weak or dead germs that can cause diseases —viruses, bacteria or toxins, the US Department of Health and Human Services said.

It stimulates the immune system to produce antibodies, exactly like it would if a person were exposed to the disease.

“Unlike most medicines, which treat or cure diseases, vaccines prevent them,” the U.S. Centers for Disease Control and Prevention said.

Developed by the Japanese firm Fujifilm, Avigan tablet was approved for manufacture and sale in Japan as an influenza antiviral drug in 2014, five years before the outbreak of the disease caused by the new coronavirus.

There is still no vaccine and no specific antiviral medicine to prevent or treat COVID-2019, the World Health Organization said. A global group of experts is working under WHO’s coordination to speed up development of the vaccines.

Despite its approval in 2014, Avigan has never been generally distributed in the market, is not available at hospitals and pharmacies in Japan, and is only manufactured and distributed when requested by the Japanese government, Fujifilm said.

It is considered for use only in an outbreak of novel or re-emerging influenza virus infections in which other antiviral drugs are “not effective or insufficiently effective” and only when the Japanese government decides to use it, the firm added.

The anti-flu drug gained prominence after a Chinese science and technology official, Health Zhang Xinmin, told reporters March 17 it “has a high degree of safety and is clearly effective in treatment.” (Read a related fact check: Headline on discovery of COVID-19 drug false; story needs context).

He said results of clinical trials conducted on 200 patients in China showed that patients who received Avigan tested negative in a median of four days and pneumonia symptoms were markedly reduced.

According to Fujilim, Avigan has a mechanism to selectively inhibit RNA polymerase involved in influenza viral replication and is expected to have an antiviral effect on SARS-CoV-2. The new coronavirus is classified into the same type of single-stranded RNA virus as influenza, it said.

The demand for Avigan led Fujifilm to begin the third phase of clinical trials of the drug for COVID-19 patients in Japan on March 31. It started testing the drug on COVID-19 patients in the United States in April.

Johns Hopkins University and Medicine has recorded more than 2 million infections and 128,886 deaths from COVID-19 globally as of April 15. The U.S. has become the epicenter of the pandemic, with 609,995 confirmed cases and 26,069 deaths. Japan has a reported 8,100 cases and 146 deaths.

Fujifilm has increased its monthly production of Avigan as the Japanese government intends to stockpile two million treatment courses of the drug as part of its emergency economic package.

In his message at the Asean Plus 3 summit, Duterte urged all countries to ensure fair and easy access to vaccines and treatments.

Estimates show it will likely take 18 months to get the vaccine to the market.

A vaccine is developed in the lab and tested on animals before it is tried on human. Clinical trials, in turn, are divided into three phases, each of which involves more people than the previous one and thus takes longer. The vaccine also has to be licensed by regulatory agencies.

“While a vaccine for general use takes time to develop, a vaccine may ultimately be instrumental in controlling this worldwide pandemic,” the group of experts working under WHO’s coordination to develop a vaccine against COVID-19 said in statement.


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