President Donald Trump has previously promised that rising temperatures would make COVID-19 "miraculously" go away. At a rally back in February, Trump told supporters, "as the heat comes in, typically that will go away in April." As we approach mid-April, the U.S. has nearly 430,000 cases and more than 14,800 deaths, per a New York Times case tracker. More than 89,000 have died worldwide.

But a panel of experts from the National Academies of Sciences, Engineering, and Medicine has concluded that may not be the case, in a letter an infectious diseases committee wrote to the White House.

In the April 7th letter, the NAS's committee on Emerging Infectious Diseases and 21st Century Health Threats say there isn't enough evidence to say that summer weather will lessen coronavirus cases.

The committee reviewed a host of different studies with varying findings and each with their own limitations.The committee found that studies published on how temperature and humidity impacted the virus "have conflicting results" and are "hampered by poor data quality, confounding factors, and insufficient time since the beginning of the pandemic from which to draw conclusions."

The letter noted that Australia and Iran are "experiencing rapid virus spread" despite their current warm temperatures. Additionally, because of the lack of immunity in humans, any effect warmer climates have on the virus's spread "may not be as apparent as with other respiratory viruses for which there is at least some pre-existing partial immunity."

Other pandemics among influenza strains have not shown seasonal patterns either, the letter reads. (The author referred to influenza strains resulting in pandemics, not epidemics or a seasonal increase of cases.)

"There have been 10 influenza pandemics in the past 250-plus years—two started in the northern hemisphere winter, three in the spring, two in the summer and three in the fall. All had a peak second wave approximately six months after emergence of the virus in the human population, regardless of what initial introduction occurred," the letter says.

The first cases of COVID-19 in New York originated from Europe or other parts of the U.S., rather than countries in Asia, according to new research analyzing the dozens of genetic material from the virus in New York patients.

A team of researchers at the Icahn School of Medicine at Mount Sinai found New York's early cases of coronavirus match the genetic material of the virus from Europe,

The Mount Sinai team looked at 84 cases across 21 NYC neighborhoods in Manhattan, Bronx, Queens, and Brooklyn as well as two towns in Westchester County from March 18th or earlier. They were compared to more than 2,300 genomes of the virus, officially called severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2, available through an online database called the Global Initiative on Sharing All Influenza Data.

Researchers determined the origin of the novel coronavirus strains in NYC had mostly come from Europe.

The analysis "indicates multiple independent but isolated introductions mainly from Europe and other parts of the United States," a co-author of the Mount Sinai study and genetics and genomic sciences professor, Harm van Bakel, said in a statement.

"Only one of the cases studied was infected with a virus that was a clear candidate for introduction from Asia, and that virus is mostly closely related to viral isolates from Seattle, Washington," said Viviana Simon, a microbiology and infectious diseases professor at Mount Sinai's school of medicine.

The Mount Sinai team's research suggests that the virus was spreading through the NYC area as early on as late January, according to Simon.

A separate team of researchers at NYU Grossman School of Medicine found similar results in early data. That team evaluated 91 cases and found the coronavirus appears to have been spreading in the city a couple of months before testing began and most virus samples originated from Europe.

The findings show the narrative that the virus had spread from China is misleading; that narrative -- reinforced by Trump repeatedly referring to COVID-19 as "the Chinese virus" -- has contributed to racist backlash and attacks against Asians in NYC and impacted local businesses in Asian communities even before cases were confirmed in New York.

Though the virus was likely spreading as early on as January in New York City, Trump had issued a ban on non-citizens for traveling from China, where the first case of the virus was detected late last year, January 31st. Then on March 11th, he issued a suspension of travel from Europe for most non-citizens, though experts say travel bans don't work once the virus is spreading within the country itself.