November 27 coronavirus news

While modeling studies have suggested that around 60 to 70% of the population would need to be immune to Covid-19 in order to achieve herd immunity, targeted vaccination may be needed to defeat the virus, said Dr. Mike Ryan, executive director of the World Health Organization’s health emergencies program.

Ryan said it may take “some very clever vaccination strategies” that target people in society who are more likely to carry, transmit and spread the virus.

Herd immunity is built around the idea that disease spreads evenly through a community and that everyone’s absolute risk of being infected is about the same, Ryan explained during a news briefing in Geneva on Friday.

But the virus does not spread evenly. 

If there are lots of protected people surrounding those who are unprotected then “effectively, there’s a barrier. There’s a firewall around some who are not vaccinated, a firewall of vaccinated people, and therefore you can achieve control and eradication, sometimes, without vaccinating everyone,” he said.

While an overall number may be important in terms of policy, Ryan said it will be important to be strategic about which groups are targeted for vaccination.

“It may be much more important to target certain sections of the community than it will be to necessarily target some others who may not be participating in transmission as much,” he said.

And the vaccine may not be a miraculous solution to the pandemic, he cautioned. “I don’t think anyone can promise eradication of this virus until we understand much more about the vaccine, and much more about how the vaccines work in the real world and until we understand much more about the details of transmission of this virus.”

Katherine O’Brien, director of Immunization, Vaccines and Biologicals at WHO, added to Ryan’s point with the example of measles. Last year was a terrible year for measles outbreaks globally, she said.

“Many of those outbreaks were happening in countries that had very high measles vaccine coverage,” she said. “But it wasn’t about the whole country’s coverage that was important, it was about the sub communities, the sub national coverage.”

With the right tools, distribution of Pfizer’s coronavirus vaccine – which requires ultra-cold storage – is possible, but people may need to be strategic about where they allocate those resources, a World Health Organization (WHO) official said Friday.

The task does require enormous resources, and people may need to use a targeted distribution approach, O’Brien said during a news briefing in Geneva.

“Part of the approach that many countries may take is to choose to use vaccines that require an ultra-cold chain for only certain portions of the population that need to be vaccinated,” she added.

O’Brien said some may choose to use the vaccine among health care workers, in facilities where installing an ultra-cold freezer may be more simple than in other settings.

“Every country is going to have to work very hard and is going to have to innovate around systems to actually deliver vaccines that do have an ultra-cold chain,” O’Brien added, citing solutions like portable freezers and dry ice.

O’Brien noted that Pfizer has developed special thermal shippers to transport the vaccines, which can maintain the temperature of the vaccines for about 10 to 15 days.

“The intention is certainly to be able to use it, along with other vaccines because no one vaccine is going to have adequate supply, nor will any one vaccine necessarily have suitable operational characteristics to meet all of the needs,” she said.

Remember: Pfizer and BioNTech submitted on Nov. 20 to the US Food and Drug Administration for emergency use authorization for their coronavirus vaccine candidate.

Emergency use authorization, or EUA, from the FDA is not the same as full approval. An EUA allows products to be used under particular circumstances before all the evidence is available for approval. 

The FDA intends to make a decision about authorizing Pfizer and BioNTech’s coronavirus vaccine within a few weeks of a key meeting scheduled for Dec. 10, according to an agency official.

The number of coronavirus patients hospitalized and in intensive care units in France has continued to decline since Nov. 17, according to figures released by the French Health Agency on Friday. 

There are currently 28,620 Covid-19 patients in France’s hospitals, a decrease of 662 from Thursday.

In addition, the number of patients in intensive care units is down by 695 from last Friday’s figures. There are now 3,871 Covid-19 patients in intensive care units.

Data released also shows the positivity rate of people tested for Covid-19 over the past seven days keeps decreasing with 11.7% on Friday, compared to almost 18% two weeks ago.

France registered 12,459 new coronavirus cases Friday, bringing the total to 2,196,119.

Brazilian President Jair Bolsonaro said Thursday that while his government will distribute the approved coronavirus vaccines free of charge to the population, he personally will not take one.

Bolsonaro has repeatedly downplayed the severity of Covid-19, even after contracting the virus in July, and has raised doubts about future vaccines.

During his weekly broadcast streamed live on social media Thursday night, Bolsonaro said the federal government would purchase vaccines approved by the regulatory commission Anvisa, and "place them at the disposal of the population for free and on a voluntary basis.”

He also said that Congress is unlikely to make the vaccine mandatory.

Brazil has the second-highest number of Covid-19-related deaths worldwide and the third-highest number of total cases.

A committee that advises the US Centers for Disease Control and Prevention about vaccines has scheduled an emergency meeting for Tuesday.

The Advisory Committee on Immunization Practices posted the meeting announcement on its website with little explanation.

While it does not say explicitly that the meeting is to discuss coronavirus vaccine distribution, there’s no other likely reason for such a meeting to be called.

A CDC spokesperson later confirmed the meeting was called to discuss coronavirus vaccines but could not provide more details.

ACIP met on Monday to discuss whether to recommend any coronavirus vaccine that might get emergency use authorization (EUA) from the US Food and Drug Administration and to talk about who should be first in line to get one.

While the FDA approves or authorizes a vaccine, it’s the CDC, based on ACIP’s advice, that decides who should get vaccines and when.

ACIP usually meets regularly three times a year but the approval of a pandemic vaccine is an unusual circumstance.

The CDC did not immediately answer requests for explanation about the meeting.

So far, Pfizer is the only company to apply for an EUA from the FDA. The submission to the FDA was based on results from the Phase 3 clinical trial of Pfizer's vaccine, which began in the United States on July 27 and enrolled more than 43,000 volunteers.

More information and research is needed to understand the difference in efficacies of AstraZeneca vaccine dose schedules and whether a new trial is needed to check the efficacy of the lower dosage, World Health Organization officials said during a news briefing in Geneva on Friday.

There is only so much that can be included in a release, she said, and it needs to be reviewed in terms of the data and questions asked about the data that may come up during the review.

“It’s difficult to weigh in on this,” O’Brien said. “I think what we can emphasize, though, is that from what we understand about the press release, there is certainly something interesting that has been observed, but there are many reasons that could underlie the differences that were observed.”

More information, including evaluations of the immune response in the trial, is needed, she said.

Dr. Soumya Swaminathan, WHO’s chief scientist, agreed with O’Brien, saying that everything that is known is from the news release, and it appears that less than 3,000 people were given the half dose, then full dose of the vaccine.

It is also understood that no one over the age of 55 was in that group. The group given two full doses were larger numbers and had different age groups.

“It’s very hard to compare these two groups and that I would say the numbers are still small to really come to any definitive conclusions,” she said.

“Now, of course, the advantage of using a smaller dose, particularly if you’re getting higher efficacy, is great and you can save on the vaccine and at the same time you are benefitting from higher efficacy, but I think it would be speculation at this point,” she said.

Swaminathan said that they have heard that AstraZeneca would like to do a full trial of the half dose full dose schedule, “if we are to explore this hypothesis of having perhaps a better efficacy with a lower dose, then it would need a trial.”

Remember: The US Food and Drug Administration requires a threshold of at least 50% efficacy. It is not clear if the FDA will authorize emergency use however.

AstraZeneca has not yet tested its half-strength dose in the US either. But on Thursday, a spokesperson for the company told CNN their aim was to include the half-strength dose regimen into their US trials, which currently has around 10,000 participants.

If you ended up traveling for Thanksgiving, there are steps you can take to prevent any further spread of coronavirus.

Try to be outdoors as much as possible, advises Dr. Leana Wen, an emergency room physician and former Baltimore health commissioner. 

“Do not gather indoors, especially not for meals. … Have your meals outside as much as you can. If you’re indoors, open all the windows and all the doors. Make sure to wear masks anytime you're around people who are not in your immediate household,” Wen said in an interview on CNN. 

Wen said that once people travel back to their homes, they should quarantine and then get tested. 

“Then when you return to your home communities, I would encourage people to quarantine. Quarantine for at least seven days, and then get tested. If you cannot get tested, quarantine for 14 days. And the reason is we don't want to see coronavirus wherever it is that we’re going back home to, given how high the level of Covid is all throughout the country,” she said. 

Watch:

Citing the potential impact that the Thanksgiving holiday might have on the number of future Covid-19 cases, Vermont issued updated guidance to residents.

Speaking on behalf of the Vermont Department of Health, Dr. Mark Levine said “my request to Vermonters who may have participated in travel or multi-household gatherings is simply this: please quarantine yourselves at home and please get tested now and in seven days.”

Citing rising case numbers, Levine pleaded with Vermonters to avoid any nonessential travel and any gatherings, particularly those between households.

Despite lower levels of reported holiday and pre-holiday air travel, various surveys conducted prior to Thanksgiving had estimated between a quarter and a third of all Americans planned to dine with people outside of their immediate household.

“Such surveys probably underestimate reality, as people don’t always want to freely admit doing what they have been told not to do,” acknowledged Levine. Nonetheless, Levine noted that Vermont was among the top three regions in the country with the fewest respondents planning on dining with others, the others being Washington state and the District of Columbia.

Vermont's numbers: The state has reported 4,005 cases of coronavirus and 67 deaths since the pandemic started. 

Note: These numbers were released by Vermont’s public health agency and may not line up exactly in real time with CNN’s database drawn from Johns Hopkins University and the Covid Tracking Project.

As coronavirus cases across Canada rise, Prime Minister Justin Trudeau said the country is "in some of the toughest days of this pandemic" and warned residents of what is come.

He asked Canadians to avoid gatherings, wear a mask, and follow health guidelines. But he also highlighted that, “vaccines are on the horizon — there's a light at the end of the tunnel.”

Trudeau announced that Canada is setting up a national operation center through the Public Health Agency of Canada and the Canadian Armed Forces. This team will coordinate logistics and distribution of vaccines. 

The operation center will work through issues around vaccine cold storage, as well as data sharing and reaching indigenous and rural communities.

“Canada is well prepared for large scale rollouts of vaccines, but this will be the biggest immunization in the history of the country. We must reach everyone who wants a vaccine, no matter where they live,” he said. 

Speaking in French, Trudeau aded that “we are now less than a month away from the holiday season. I know that December will be difficult for a lot of people, but don't forget that the present situation isn't permanent,” he said through an interpreter. “There is light at the end of the tunnel. In the meantime, we must hold on a little longer.”

According to the Public Health Agency of Canada, the country averages 5,194 new cases per day. The agency tests roughly 75,666 people daily, which correlates to a 7.6% percent positivity.

Over the last week the country saw an average of 2,072 hospitalizations from Covid-19. At least 428 of them were in the intensive care unit.