The Russian president said that the vaccine developed at the Gamaleya Institute had been approved by his country's health ministry.
Philippines president said Russia had offered his country the vaccine and promised to be one of the first to receive it to prove it was safe.
If there is no price too high for a successful vaccine, does that change if you've already paid for 100 unsuccessful ones?
While 70 percent or more is better, Fauci said a vaccine that's 50 or 60 percent effective brings added value if it's coupled with public health measures.
Researchers point to a phenomenon called T-cell memory, which may allow white blood cells to attack variations of viruses they have encountered before.
"Usually, vaccines literally take years and years and years to develop," the vice president said.
"We shouldn't be surprised these attacks are happening. What would be surprising is if they stopped," cybersecurity expert Stefan Tanase told Newsweek.
The vice president also said the administration was getting ready to offer vaccines to tens of millions of Americans.
President of the Russian Academy of Sciences said hundreds of millions of doses could potentially be available by the start of the year.
Multiple treatments and vaccines for COVID-19 are already approaching their final trial phases after their development has been fast-tracked, President Donald Trump announced during an at-times boisterous speech in North Carolina on Monday.
The British government offers 30 million people flu jabs to alleviate healthcare pressure if the second wave of COVID-19 arrives.
By investing early, the administration hopes to prevent delays in getting a virus vaccine to the public.
The agreement followed talks held by Mexican president Andrés Manuel López Obrador with U.S. officials earlier this month.
The country aims to have 30 million doses of a vaccine for the virus this year.
Several Russian health officials have denied the allegation.
The UK has already ordered 100 million doses of the vaccine which is being developed in partnership between Oxford University and pharmaceutical company AstraZeneca.
Bloomberg reported Monday that top government officials and business tycoons had received a vaccine developed by the state-run Gamaleya Institute in Moscow.
The government believes that a vaccine offers the best chance of defeating the COVID-19 virus and getting things back to normal.
"I'm really quite cautiously optimistic that we'll be able to have something as we get into the end of this year and the beginning of next year," Dr. Anthony Fauci said Thursday.
"We believe that based on the current results it will be approved in Russia in August," Kirill Dmitriev, head of the Russian Direct Investment Fund, said.
"We are writing to underscore the vast importance of human challenge trials as a method to help develop vaccines," an open letter signed by more than 120 scientists read.
Countries around the globe must jointly put in place best practice—including mandatory mask wearing, social distancing, and above all, sharing readily available solutions—before it is too late.
There are at least 160 potential novel coronavirus vaccines in development in the U.S., Europe, China and Australia.
"We hope the vaccine could generate neutralizing antibodies in humans seen in monkeys and mice," vaccine researcher Kiat Ruxrungtham said in a press conference on July 12.
Currently, there are around 20 candidate COVID-19 vaccines in various states of clinical trials, with about 140 in pre-clinical development.
"There absolutely is a light at the end of the tunnel even if it's hard to see sometimes," said ex-Obama health care head Andy Slavitt.
The vaccine will take a different approach than other companies, focusing on boosting the body's immune response by stimulating T helper cells and high levels of neutralizing antibodies.
The University of Oxford study leader said the vaccine could offer better protection than "naturally-acquired immunity".
Potential vaccines are being trialed in the U.S., China, the U.K., Germany and Belgium.
Healthcare workers and those vulnerable to severe COVID-19 should be prioritized, experts say.