The unprecedented heat is smashing temperatures records from the San Francisco Bay area further east to Idaho and Montana, with more broken records expected tomorrow. Further south towards Death Valley, California, forecasters expect the region to break its September heat record of 125 degrees Fahrenheit. Salt Lake City, Utah has broken its previous September record of 100 degrees three times during this past week. The heatwave began on August 30 and is expected to peak today or tomorrow, with temperatures gradually falling. Some of the most excessive heat is forecast for California’s Central Valley. According to the National Weather Service, the capital city of Sacramento has a 67 percent chance to match its September record of 109 degrees tomorrow. The heat is putting immense strain on the power grid, as desperate residents crank up the air conditioning to stay safe. The California Independent System Operator (ISO), has issued multiple “Flex Alerts,” calling energy conservation between the hours 4 p.m. and 9 p.m. to avoid power outages. “California consumers and businesses have responded to our Flex Alert calls with helpful reductions in their electricity use during the grid’s most challenging hours,” said California ISO chief executive Elliot Mainzer in a video update on Saturday, ahead of the extension of the alert. “Cooperation like this makes a real difference, so thank you everyone for that help.” The agency is bracing for peak demand on Tuesday of more than 50,000 megawatts. While global warming is causing heat waves like this one to occur with greater frequency, this record-breaking heat is caused by a particularly nasty situation called a heat dome. Heat domes occur when the atmosphere acts like a giant hat and traps in hot air over land or water. According to the National Oceanic and Atmospheric Administration (NOAA), this phenomenon occurs when strong, high-pressure atmospheric conditions combine with influences from La Niña. The high pressure system pushes hot air downward, compresses it, and warms it further. This creates huge areas of sweltering heat that gets trapped under the “dome” of high-pressure. The heat dome also stop clouds from forming, making it less likely for cloud cover to block the sun’s heat or relief from rain. The air circulation patterns higher up in the atmosphere will also influence whether high pressure persists and trigger a heat wave. As prevailing winds from the Pacific Ocean move the hot air east over land, northern shifts of the jet stream trap the air and move it toward land. There, the hot air sinks, resulting in heat waves. As the arctic has warmed due to climate change, the jet stream has slowed down, causing these areas of heat to be stuck in one place longer. According to The San Francisco Chronicle, these heat domes can even overcome the cooling effect of California’s marine layer (air chilled by the Pacific Ocean). Heat domes are more commonly seen above the land, but marine heat waves can also occur. Climate change has also made California a more humid place. In an interview with The Washington Post, Alexander Gershunov from the Scripps Institution of Oceanography said, “with higher humidity, temperatures don’t really drop that much at night. And in terms of health impacts, that pretty much removes the nighttime respite that we need to face another day of scorching heat.” These overall trends are not a surprise to researchers. Of all the extreme weather events, heat waves are “the most closely-related and directly-impacted by global warming,” adds Gershunov. Heatwaves are among the most dangerous natural hazards, killing more than 166,000 people between 1998 and 2017. To keep cool (even without air conditioning) scientists recommend wearing loos fitting clothing in lighter colors that don’t absorb as much heat, staying hydrated, taking cool showers throughout the day, and blocking out the sun using curtains or shades.
title: " Popular Science" ShowToc: true date: “2022-12-06” author: “Von Blackburn”
Although the decisions still need to be confirmed by the FDA itself and the CDC, they pave the way for all at-risk Americans—and everyone who received the J&J vaccine—to receive booster shots. Last month, the FDA approved Pfizer boosters for the same at-risk groups that the FDA panel recommended for Moderna recipients this week, which are people over 65, younger people at high risk for severe COVID, and those who work in high-exposure jobs, like nursing. (The CDC has already approved third doses of Pfizer and Moderna for immunocompromised people, though those aren’t technically boosters.) In making its decision, the FDA panel relied on data from Israel, and small studies from the companies themselves. But Israel has largely vaccinated its population with Pfizer, not Moderna or J&J. And the panelists repeatedly raised concerns about the depth of drug company data, particularly on side effects. “I’ve got some real issues with this vote,” said Patrick Moore, a virologist at the University of Pittsburgh School of Medicine, after voting in favor of Moderna’s boosters. “Nonetheless, I want to explain why I voted yes on this. It’s more based on gut-feeling than real serious data.” As data reporter Betsy Ladyzhets noted in her COVID Data Dispatch Newsletter after the Pfizer booster authorization, there’s a serious lack of home-grown data underlying the entire booster process. Because the CDC doesn’t track all breakthrough infections—just serious ones—federal advisory bodies are relying on data gathered outside the US, and that may not directly pertain to the questions in front of them.
How Moderna’s data stacks up
So how exactly is the FDA making these decisions? On Thursday morning, two Israeli public health officials presented epidemiological data on the impact of Pfizer booster shots on a surge of COVID cases in August. Sharon Alroy-Preis, Israel’s director of Public Health Services, said that the country saw a steep dropoff in cases among people over 60 after boosters became available. That data is especially notable because it includes the experiences of millions of people, collected via the country’s national health service. “There is no question in my mind that the break of the curve now was due to the booster dose,” she said. At the FDA presentation, the Israeli officials said that boosters not only reduced the rate of infections, but cut the rate of severe disease by about 70 percent. In people older than 60, they said that boosters reduced deaths by 80 percent. Most panelists spoke favorably of using the Israeli findings to consider boosters for the Moderna vaccine. “I think we can probably extrapolate from the Pfizer data in Israel,” said Mark Sawyer, a pediatric infectious disease specialist at UC San Diego. “In all other ways, these two vaccines are quite similar.” But some experts raised questions about whether the two mRNA vaccines are similar enough to draw such firm conclusions. Moore, the Pittsburgh virologist, pointed out that although Pfizer and Moderna’s vaccines rely on the same mRNA technology, Moderna’s vaccine contains several times as much mRNA in each shot. And one even questioned whether Israel was drawing the right conclusions from its data. “I was not as impressed with the Israeli data as a justification,” said Michael Kurilla, a researcher at the National Institutes for Health. He said that the epidemic curve of Israel’s summer wave—with boosters on hand—looked similar to that of earlier waves, where there weren’t boosters, which led him to wonder if the shots actually made the difference. It seems clear that mRNA boosters will further protect their recipients against COVID. But when it comes to the larger questions—can we expect full protection against infection? Will boosters hold up against other highly infectious variants, like delta?—the data just isn’t in.
J&J’s data shows two doses is better than one
In the case of Johnson & Johnson’s vaccine, the situation is even more complicated. J&J is delivered as a single shot, and the company is asking to add a second dose not because it will head off waning immunity, but because it will bring its efficacy into line with the mRNA vaccines. That means that Israel’s data, which is focused on waning immunity following mRNA vaccination, is even less applicable. “The reality is that your vaccine does seem to be holding up quite well in terms of durability,” said Kurilla to J&J officials on Friday, “so the immediate need for a booster is not apparent.” But J&J’s vaccine has had a lower efficacy against all infections—around 70 percent in the US—even though it’s highly effective against hospitalization and death. “There is room to improve the efficacy,” said Penny Heaton, head of vaccine research for Janssen, J&J’s pharmaceutical division. Even though the overall efficacy was the central concern of the meeting, J&J is applying for a booster, not a revised primary dose. (Having a one-dose primary regimen means that J&J can still be potentially used to deliver immunity in places where spotty healthcare infrastructure makes it hard to get follow-up doses.) Data presented by J&J at Friday’s meeting showed that after two doses, J&J recipients in the United States were 94 percent protected against symptomatic illness. Company presenters also said that the effect was pronounced in the elderly in particular. They argued that the booster was most effective after six months, but that was based on a study that included only 17 people who received a six month booster. In the end, the panel ended up approving the booster after 2 months—essentially a second shot in a two-dose series—over that lack of data. And J&J’s data was submitted with a caveat: much of it was presented as “unverified by the FDA.” Marks, of the FDA, said that this was because the drug company had delivered data for a trial involving thousands of patients, and FDA reviewers would have needed months to fully verify it.
What the data says about the safety of booster shots
The panel also focused on data concerning the safety profiles of booster shots. Because the United States has a unified reporting system for adverse reactions to vaccines, there is a huge amount of national data on the safety of the vaccines as they’re already delivered. There are two main concerns. The first is blood clotting after the J&J vaccine, which primarily affects women in their 20s to 30s. The recognition of this rare but dangerous side effect led the United States to pause its distribution of the J&J vaccine this spring, breaking the momentum of some outreach campaigns. As of October 5, FDA officials reported 47 cases from J&J. The second is swelling of the heart muscle, known as myocarditis, which has most affected young men, and isn’t as dangerous. There have been 93 cases related to J&J, and 300 following Moderna shots as of June. Where the panelists expressed concern, however, was the extra dose, particularly in the case of Moderna. Eric Rubin, an infectious disease researcher and the editor-in-chief of the New England Journal of Medicine, said that “the safety data are very thin,” because the Moderna booster dose, which is just half the size of the 100 microgram primary doses, was only tested on 170 people. Instead, many panelists relied on Israeli data, which showed that out of 3.7 million full 100 microgram third doses delivered in Israel, there were only 44 events that required hospitalization or were life threatening. In the end, many of the panelists said they were comforted by the global data on safety—just not what they’d been presented by drug companies.
