A top World Health Organization official warned on Thursday that Europe's coronavirus outbreak is becoming a "very serious situation" due to a resurgence of new infections following a respite throughout the summer months.

"We have a very serious situation unfolding before us," said Hans Kluge, W.H.O.'s regional director for Europe, during a Thursday press briefing on the coronavirus outbreak's situation in the region. "Weekly cases have now exceeded those reported when the pandemic first peaked in Europe in March."

Last week, the region reported over 300,000 new infections with the majority of the increase coming from younger populations, similar to how new hotspots in the United States are in the surrounding areas of college campuses. However, the number of cases of those in more vulnerable populations including older individuals is also rising as well.

"More than half of European countries have reported a greater than 10% increase in cases in the past two weeks...Although these numbers reflect more comprehensive testing, it also shows alarming rates of transmission across the region," Kluge added.

As Europe heads towards its colder months, broad lockdown measures may need to be reinstated to curb the severity of impeding outbreaks. At this time the coronavirus's foothold on the region, and the entire world, depends on the rapid development and distribution of a safe and effective vaccine.

Vaccine Update

Coronavirus vaccine frontrunner Moderna (MRNA  ) released a 135-page document, called its protocol, on Thursday that details how the biotech is conducting its late-stage clinical trial of its candidate, including how the safety and efficacy of the drug will be determined. Pfizer (PFE  ) has also provided its plan for its Phase III trial, aiming to be as transparent as possible with the public.

Moderna's protocol notably suggests that the first total analysis of the large trial's data may not be conducted until December, with it possibly not providing enough information to determine if the vaccine is effective in prevention COVID-19 infection. Later analysis, scheduled for March and May, will more likely prove its efficiency.

Unlike Moderna, Pfizer's plan did not include a timeline for analysis, according to the New York Times. However, the company has in the past stated that it will likely know the effectiveness of its candidate as early as October.

Both vaccine candidates are in the middle of their late-stage clinical trials, with Moderna aiming to involve 30,000 participants and Pfizer 44,000.

Yet, the added transparency may still not be enough to persuade the American public to get a vaccine once they are approved for use by the U.S. Food and Drug Administration. According to a new Pew Research poll, only 51% of U.S. adults surveyed now say that would definitely or probably get a vaccine if its were available immediately, leaving the other half of the country unvaccinated. That is a significant drop from the 72% that said they would get a vaccine back in May.