The true number of coronavirus cases in the United States is likely to sit at 50 million – more than double the official number, research has revealed.

It comes as desperate American officials weigh up giving out a half dose of the vaccine to citizens – in a move that could jeopardise the effectiveness of the immunisation across the world.

As cases skyrocket across the US, a culture war over masks and public health measures continues, with anti-maskers holding rallies and forcing their way into shopping centres across the country in recent days.

In evidence bound to make some protesters reconsider their actions, a peer-reviewed report from Pfizer scientists has revealed that COVID-19 cases are actually going under-reported.

The writers of the research released on Wednesday morning said they had found the number of cases was actually closer to 50 million.

Official data from Johns Hopkins University showed that by Tuesday night just over 20.8 million US cases had been recorded.

Despite the explosion in cases and the fact more than 353,000 Americans have died, COVID-19 has remained a political football this week with President Donald Trump tweeting a conspiracy theory that the numbers were being over-reported.

A sign with directions for drivers at a post-immunisation area in Kentucky. Photo: Getty

“The number of cases and deaths of the China Virus is far exaggerated in the United States because of the @CDCgov’s ridiculous method of determination compared to other countries, many of whom report, purposely, very inaccurately and low,” he tweeted.

But the Pfizer report has shown the reality of US cases is actually much worse than the impression given by official data.

As of November, an estimated 46.9 million Americans or more than 14 per cent of the US population, are likely to have had COVID-19. Only about 28.1 million of those were symptomatic.

“Reported COVID-19 cases do not represent the full SARS-CoV-2 disease burden,” the report reads.

“Case reports are dependent on patients seeking health care, availability and type of care (eg, telemedicine), and testing availability.”

Tweet from @SamBraslow

Using data from public health surveillance and surveys of COVID-19 antibodies among the general population, the research shows that by mid-November more than 14 per cent of the US population had contracted COVID-19.

The US has been reporting a record number of cases in recent days, with hospitals and morgues overrun.

Despite the skyrocketing number, the country is far from herd immunity the report argues.

“The US population remains a long way from herd immunity, even with millions of new infections each week,” the report said.

Long lines in Los Angeles queue for COVID-19 testing. Photo: Getty

Not only are the current official numbers of cases likely to be well below the actual number, so are the official deaths.

“The number of estimated COVID-19 deaths is also remarkably more than the reported deaths in the US through November 15, 2020,” the report reads.

“Supporting the conclusion that approximately 35 per cent of COVID-19 deaths are not reported.”

Vaccine jeopardy

About 15.4 million vaccine doses have been distributed in the US, with only 4.5 million people receiving their first dose.

The rollout is moving slowly – health officials had wanted 20 million people vaccinated by the end of 2020.

Because of the slow progress, the US Food and Drug Administration is considering giving half-doses of Moderna’s COVID-19 vaccine to people age 18 to 55.

Moncef Slaoui, the chief scientific adviser of the federal Operation Warp Speed, said clinical data showed the vaccine can be just as effective at half-doses in that age group.

Members of the New York fire department wait to receive the coronavirus vaccine.

But there are concerns this could jeopardise the effectiveness of the vaccine for the rest of the world.

Melbourne’s Burnet Institute chief executive Professor Brendan Crabb said the decision to split the vaccine would save lives but make it less effective.

“In 99 cases out of 100 it is very unwise to do this,” he told The New Daily. 

“But, of course, we are in that one in 100 event. I can understand why it is being considered.

“In the UK, for example, there is modelling that says if they do one dose, and give the second dose to someone else, they might save 6000 lives, because you can get extra people vaccinated.”

CEO of Melbourne’s Burnet Institute, Professor Brendan Crabb.

But splitting the vaccine also created “perfect conditions” for the virus to mutate earlier than expected, which could put the effectiveness at risk, he said.

“Where you only partially vaccinate, you run the risk generating mutations that escape the vaccine,” Professor Crabb said.

“Once you generate a virus mutation all vaccines are less effective.”

Although there was “a lot riding on doing it properly” the sheer number of cases in the US and UK mean desperate measures were being considered to save lives, he said.

“I don’t think anyone could have imagined the numbers. There’s a person dying every 50 seconds in the UK and every 33 seconds in the US.”

Anti-mask protests

California has been one of the worst-hit areas in terms of rapidly increasing case numbers, with many of the state’s hospitals and morgues overrun.

Despite this anti-mask protests have continued to grow, with campaigners targeting shopping centres and supermarkets.

Tweet from @SamBraslow

On Saturday “Burn the Mask” protesters blocked an entrance to a Trader Joe’s grocery store in Fresno, forcing it to close early.

In Los Angeles, where nearly one in five people are testing positive, a group of protesters stormed a Ralphs grocery store and argued with customers about masks.

The group, some showing support for Mr Trump with Make America Great Again clothing, then went to terrorise customers in a Westfield mall where they chanted “no more masks” and “f–k Communist China”.