The vaccine for the coronavirus disease 2019 (Covid-19) developed by Russia’s Gamaleya National Center of Epidemiology and Microbiology has been issued an emergency use authorization (EUA) by the Food and Drug Administration (FDA).

In an online press conference on Friday, FDA Director-General Eric Domingo said the EUA was issued after a “rigorous and thorough review” by regulatory and medical experts of both published and unpublished data on the vaccine.

“The interim data from the ongoing phase three trials as published in Lancet show that the vaccine has overall efficacy of 91.6 percent in preventing Covid-19 (coronavirus disease 2019). And the efficacy rate is consistent among all age groups, 18 and older,” Domingo said.

The vaccine is administered in two doses of 0.5 ml intramuscular injections 21 days apart.

He said the adverse events reported from the vaccine were “mostly mild and transient, similar to common vaccine reactions.”

In a Facebook post, the Department of Health (DOH) said these “common adverse events” observed in the vaccine’s phase three clinical trials include local adverse events such as pain on injection site and swelling as well as systemic adverse events such as hyperthermia, headache, asthenia, muscle/joint pain, malaise, sore throat, diarrhea, rhinorrhea, loss of appetite, pain in the oropharynx, nasal congestion, colds, sneezing, and coughing.

While no serious adverse events were initially reported, Domingo said the above adverse events only reflect “limited follow-up and more adverse effects may emerge”.

“That is why, same as all vaccines under EUA, close surveillance and monitoring are needed after immunization,” Domingo said.

Like other Covid-19 vaccines issued with a EUA, he said the Sputnik V vaccine has not been issued a marketing authorization or Certificate of Product Registration, with only the DOH, the National Task Force Against Covid-19, and their designees allowed to purchase the vaccine from its local distributor, Philippine Archipelago International Trading Corporation.

Domingo said the EUA was issued based on three conditions—that it is reasonable to believe that the vaccine may be effective against Covid-19, that the vaccine’s known and potential benefits outweigh its known and potential risks; and that there is no adequate, approved and available alternative vaccine for preventing Covid-19.

“As of this time, there is no completely registered or licensed Covid-19 vaccine in the Philippines or anywhere else in the world. All of the vaccines, for now, are under a EUA,” Domingo said.

To date, the FDA has issued EUA to three other Covid-19 vaccines, the Pfizer-BioNTech, the AstraZeneca, and Sinovac’s CoronaVac.