The Dow and S&P 500 indexes rallied on Monday after Moderna announced preliminary trial data showed its COVID-19 vaccine to be 94.5 percent effective – the second promising announcement from the vaccine front in as many weeks.

The Dow Jones Industrial Average vaulted more than 364 points or 1.23 percent at the open of trading on Wall Street, bringing the 30-share index within striking distance of the 30,000 mark.

The broader S&P 500 index – a proxy for the health of US retirement and college savings accounts – jumped 0.76 percent at the open after posting a new record close on Friday.

The Nasdaq Composite Index meanwhile opened virtually unchanged as investors continued to dump Big Tech in favor of shares beaten down by the pandemic.

Shares of Moderna rocketed 10.47 percent in the opening minutes of trading after the biotech firm became the second US company to report positive results from trials of its COVID-19 vaccine candidate.

Last week, Pfizer Inc reported that late-state trial data from the vaccine it is developing with Germany's BioNTech showed it to be more than 90 percent effective.

The double dose of good news is propelling hopes that a game-changer is within sight to vanquish the pandemic and put the US and global economies on track for "normalization".

"After almost a year in which COVID-19 has ravaged the global economy, there is finally light at the end of the tunnel," Neil Shearing, Group Chief Economist at Capital Economics, wrote in a Monday note.

Shearing also warned that the current optimism may be short lived as economies grapple with surging infection rates.

"The good news on vaccines is tempered by the fact that they won't come soon enough to prevent a difficult winter for many economies," Shearing said.

Infections continue to spike across the United States, with confirmed COVID-19 infections topping the 11 million mark over the weekend, according to Johns Hopkins University.

The wave has ushered in more business-sapping restrictions across the nation as state and local authorities try to contain the spread of the disease.

(With input from agencies)