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Why it takes 2 shots to make mRNA vaccines do their antibody-creating best – and what the data shows on delaying the booster dose

With slow vaccine distribution and manufacturing, some people won’t get the second dose on time. But does it matter?

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After a second dose of the COVID-19 mRNA vaccine, a swarm of antibodies attacks the virus. Kateryna Kon/Science Photo Library via Getty Images

With the U.S. facing vaccination delays because of worker shortages and distribution problems, federal health officials now say it’s OK to push back the second dose of the two-part vaccine by as much as six weeks.

As an infectious disease doctor, I’ve been fielding a lot of questions from my patients as well as my friends and family about whether the COVID-19 vaccine will still work if people are late receiving their second dose.

Why you need two doses 3-4 weeks apart

Two doses, separated by three to four weeks, is the tried-and-true approach to generate an effective immune response through vaccination, not just for COVID but for hepatitis A and B and other diseases as well.

The first dose primes the immune system and introduces the body to the germ of interest. This allows the immune system to prepare its defense. The second dose, or booster, provides the opportunity for the immune system to ramp up the quality and quantity of the antibodies used to fight the virus.

In the case of the Pfizer and Moderna COVID-19 vaccines, the second dose increases the protection afforded by the vaccine from 60% to approximately 95%.

Why the CDC decided receiving the second dose within 42 days is OK

In the clinical trial, the second dose of the Pfizer vaccine was administered as early as day 19 and as late as day 42 to 93% of the subjects. Since protection was approximately 95% for everyone who was vaccinated within this time “window,” there is little reason not to allow some flexibility in the timing of the second dose 2.

As more vaccine becomes available, the timing of the second dose should be close to four weeks for the Pfizer and Moderna vaccines. But the good news is that even while supplies remain limited, the science suggests that there’s nothing bad about getting a second dose as late as 42 days after the first.

What the immune system does between the first and second dose

The biology through which the mRNA vaccines induce their protection from COVID-19 is fundamentally different from that with other vaccines.

Pfizer and Moderna vaccines use messenger RNA that encodes the spike glycoprotein. Upon injection of the vaccine, the mRNA enters into immune cells called dendritic cells. The dendritic cells use the instructions written in the mRNA to synthesize the hallmark spike glycoprotein, which characterizes the SARS-CoV-2 virus that causes COVID-19. These immune cells then show the spike glycoprotein to B-cells, which then make anti-spike antibodies.

Dendritic cells recognize viruses and present information about the spike protein to T-cells. T-cells provide information about the viral spike protein to B-cells, which are transformed to memory B-cells that store information about the virus. When this memory B-cell is activated with an infection or the second dose of the vaccine, this causes some of the B-cells to change into plasma B-cells that secrete protective antibodies that fight the virus. Kateryna Kon/Science Photo Library via Getty Images

The mRNA vaccines are uniquely capable of inducing a special kind of immune cell – called a T-follicular helper cell – to help B-cells produce antibodies. The T-cells do this through direct contact with the B-cells and by sending chemical signals that tell the B-cells to produce antibodies. It is this help in antibody production that makes these vaccines so effective.

But not all B-cells are the same. There are two kinds that make anti-spike antibodies: long-lived plasma cells and memory B-cells. The long-lived plasma cells, as their name implies, live in the bone marrow for years after vaccination, continuously churning out antibody – in this case anti-spike antibody. These long-lived B-cells do not need to be boosted.

The memory B-cells, on the other hand, live in a state akin to hibernation. They do not produce antibodies until stimulated by a booster of the vaccine, or are exposed to infection with the coronavirus that causes COVID-19. That is the reason we need that second dose. Together these two types of B-cells provide a constant level of protection.

What happens if you don’t get the Pfizer or Moderna second dose on time?

With current vaccine shortages, and problems with setting up the infrastructure to vaccinate millions of people, many physicians are concerned that the second dose of vaccine won’t be delivered in the prescribed three-to-four-week window.

That booster shot is necessary for the T-cells to stimulate the memory B-cells to produce massive quantities of antibodies. If the booster isn’t given within the appropriate window, lower quantities of antibodies will be produced that may not provide as powerful protection from the virus.

[Deep knowledge, daily. Sign up for The Conversation’s newsletter.]

William Petri receives research funding from the NIH, the Bill & Melinda Gates Foundation and Regeneron, Inc.

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate…

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Low Iron Levels In Blood Could Trigger Long COVID: Study

Authored by Amie Dahnke via The Epoch Times (emphasis ours),

People with inadequate iron levels in their blood due to a COVID-19 infection could be at greater risk of long COVID.

(Shutterstock)

A new study indicates that problems with iron levels in the bloodstream likely trigger chronic inflammation and other conditions associated with the post-COVID phenomenon. The findings, published on March 1 in Nature Immunology, could offer new ways to treat or prevent the condition.

Long COVID Patients Have Low Iron Levels

Researchers at the University of Cambridge pinpointed low iron as a potential link to long-COVID symptoms thanks to a study they initiated shortly after the start of the pandemic. They recruited people who tested positive for the virus to provide blood samples for analysis over a year, which allowed the researchers to look for post-infection changes in the blood. The researchers looked at 214 samples and found that 45 percent of patients reported symptoms of long COVID that lasted between three and 10 months.

In analyzing the blood samples, the research team noticed that people experiencing long COVID had low iron levels, contributing to anemia and low red blood cell production, just two weeks after they were diagnosed with COVID-19. This was true for patients regardless of age, sex, or the initial severity of their infection.

According to one of the study co-authors, the removal of iron from the bloodstream is a natural process and defense mechanism of the body.

But it can jeopardize a person’s recovery.

When the body has an infection, it responds by removing iron from the bloodstream. This protects us from potentially lethal bacteria that capture the iron in the bloodstream and grow rapidly. It’s an evolutionary response that redistributes iron in the body, and the blood plasma becomes an iron desert,” University of Oxford professor Hal Drakesmith said in a press release. “However, if this goes on for a long time, there is less iron for red blood cells, so oxygen is transported less efficiently affecting metabolism and energy production, and for white blood cells, which need iron to work properly. The protective mechanism ends up becoming a problem.”

The research team believes that consistently low iron levels could explain why individuals with long COVID continue to experience fatigue and difficulty exercising. As such, the researchers suggested iron supplementation to help regulate and prevent the often debilitating symptoms associated with long COVID.

It isn’t necessarily the case that individuals don’t have enough iron in their body, it’s just that it’s trapped in the wrong place,” Aimee Hanson, a postdoctoral researcher at the University of Cambridge who worked on the study, said in the press release. “What we need is a way to remobilize the iron and pull it back into the bloodstream, where it becomes more useful to the red blood cells.”

The research team pointed out that iron supplementation isn’t always straightforward. Achieving the right level of iron varies from person to person. Too much iron can cause stomach issues, ranging from constipation, nausea, and abdominal pain to gastritis and gastric lesions.

1 in 5 Still Affected by Long COVID

COVID-19 has affected nearly 40 percent of Americans, with one in five of those still suffering from symptoms of long COVID, according to the U.S. Centers for Disease Control and Prevention (CDC). Long COVID is marked by health issues that continue at least four weeks after an individual was initially diagnosed with COVID-19. Symptoms can last for days, weeks, months, or years and may include fatigue, cough or chest pain, headache, brain fog, depression or anxiety, digestive issues, and joint or muscle pain.

Tyler Durden Sat, 03/09/2024 - 12:50

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Walmart joins Costco in sharing key pricing news

The massive retailers have both shared information that some retailers keep very close to the vest.

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As we head toward a presidential election, the presumed candidates for both parties will look for issues that rally undecided voters. 

The economy will be a key issue, with Democrats pointing to job creation and lowering prices while Republicans will cite the layoffs at Big Tech companies, high housing prices, and of course, sticky inflation.

The covid pandemic created a perfect storm for inflation and higher prices. It became harder to get many items because people getting sick slowed down, or even stopped, production at some factories.

Related: Popular mall retailer shuts down abruptly after bankruptcy filing

It was also a period where demand increased while shipping, trucking and delivery systems were all strained or thrown out of whack. The combination led to product shortages and higher prices.

You might have gone to the grocery store and not been able to buy your favorite paper towel brand or find toilet paper at all. That happened partly because of the supply chain and partly due to increased demand, but at the end of the day, it led to higher prices, which some consumers blamed on President Joe Biden's administration.

Biden, of course, was blamed for the price increases, but as inflation has dropped and grocery prices have fallen, few companies have been up front about it. That's probably not a political choice in most cases. Instead, some companies have chosen to lower prices more slowly than they raised them.

However, two major retailers, Walmart (WMT) and Costco, have been very honest about inflation. Walmart Chief Executive Doug McMillon's most recent comments validate what Biden's administration has been saying about the state of the economy. And they contrast with the economic picture being painted by Republicans who support their presumptive nominee, Donald Trump.

Walmart has seen inflation drop in many key areas.

Image source: Joe Raedle/Getty Images

Walmart sees lower prices

McMillon does not talk about lower prices to make a political statement. He's communicating with customers and potential customers through the analysts who cover the company's quarterly-earnings calls.

During Walmart's fiscal-fourth-quarter-earnings call, McMillon was clear that prices are going down.

"I'm excited about the omnichannel net promoter score trends the team is driving. Across countries, we continue to see a customer that's resilient but looking for value. As always, we're working hard to deliver that for them, including through our rollbacks on food pricing in Walmart U.S. Those were up significantly in Q4 versus last year, following a big increase in Q3," he said.

He was specific about where the chain has seen prices go down.

"Our general merchandise prices are lower than a year ago and even two years ago in some categories, which means our customers are finding value in areas like apparel and hard lines," he said. "In food, prices are lower than a year ago in places like eggs, apples, and deli snacks, but higher in other places like asparagus and blackberries."

McMillon said that in other areas prices were still up but have been falling.

"Dry grocery and consumables categories like paper goods and cleaning supplies are up mid-single digits versus last year and high teens versus two years ago. Private-brand penetration is up in many of the countries where we operate, including the United States," he said.

Costco sees almost no inflation impact

McMillon avoided the word inflation in his comments. Costco  (COST)  Chief Financial Officer Richard Galanti, who steps down on March 15, has been very transparent on the topic.

The CFO commented on inflation during his company's fiscal-first-quarter-earnings call.

"Most recently, in the last fourth-quarter discussion, we had estimated that year-over-year inflation was in the 1% to 2% range. Our estimate for the quarter just ended, that inflation was in the 0% to 1% range," he said.

Galanti made clear that inflation (and even deflation) varied by category.

"A bigger deflation in some big and bulky items like furniture sets due to lower freight costs year over year, as well as on things like domestics, bulky lower-priced items, again, where the freight cost is significant. Some deflationary items were as much as 20% to 30% and, again, mostly freight-related," he added.

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Walmart has really good news for shoppers (and Joe Biden)

The giant retailer joins Costco in making a statement that has political overtones, even if that’s not the intent.

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As we head toward a presidential election, the presumed candidates for both parties will look for issues that rally undecided voters. 

The economy will be a key issue, with Democrats pointing to job creation and lowering prices while Republicans will cite the layoffs at Big Tech companies, high housing prices, and of course, sticky inflation.

The covid pandemic created a perfect storm for inflation and higher prices. It became harder to get many items because people getting sick slowed down, or even stopped, production at some factories.

Related: Popular mall retailer shuts down abruptly after bankruptcy filing

It was also a period where demand increased while shipping, trucking and delivery systems were all strained or thrown out of whack. The combination led to product shortages and higher prices.

You might have gone to the grocery store and not been able to buy your favorite paper towel brand or find toilet paper at all. That happened partly because of the supply chain and partly due to increased demand, but at the end of the day, it led to higher prices, which some consumers blamed on President Joe Biden's administration.

Biden, of course, was blamed for the price increases, but as inflation has dropped and grocery prices have fallen, few companies have been up front about it. That's probably not a political choice in most cases. Instead, some companies have chosen to lower prices more slowly than they raised them.

However, two major retailers, Walmart (WMT) and Costco, have been very honest about inflation. Walmart Chief Executive Doug McMillon's most recent comments validate what Biden's administration has been saying about the state of the economy. And they contrast with the economic picture being painted by Republicans who support their presumptive nominee, Donald Trump.

Walmart has seen inflation drop in many key areas.

Image source: Joe Raedle/Getty Images

Walmart sees lower prices

McMillon does not talk about lower prices to make a political statement. He's communicating with customers and potential customers through the analysts who cover the company's quarterly-earnings calls.

During Walmart's fiscal-fourth-quarter-earnings call, McMillon was clear that prices are going down.

"I'm excited about the omnichannel net promoter score trends the team is driving. Across countries, we continue to see a customer that's resilient but looking for value. As always, we're working hard to deliver that for them, including through our rollbacks on food pricing in Walmart U.S. Those were up significantly in Q4 versus last year, following a big increase in Q3," he said.

He was specific about where the chain has seen prices go down.

"Our general merchandise prices are lower than a year ago and even two years ago in some categories, which means our customers are finding value in areas like apparel and hard lines," he said. "In food, prices are lower than a year ago in places like eggs, apples, and deli snacks, but higher in other places like asparagus and blackberries."

McMillon said that in other areas prices were still up but have been falling.

"Dry grocery and consumables categories like paper goods and cleaning supplies are up mid-single digits versus last year and high teens versus two years ago. Private-brand penetration is up in many of the countries where we operate, including the United States," he said.

Costco sees almost no inflation impact

McMillon avoided the word inflation in his comments. Costco  (COST)  Chief Financial Officer Richard Galanti, who steps down on March 15, has been very transparent on the topic.

The CFO commented on inflation during his company's fiscal-first-quarter-earnings call.

"Most recently, in the last fourth-quarter discussion, we had estimated that year-over-year inflation was in the 1% to 2% range. Our estimate for the quarter just ended, that inflation was in the 0% to 1% range," he said.

Galanti made clear that inflation (and even deflation) varied by category.

"A bigger deflation in some big and bulky items like furniture sets due to lower freight costs year over year, as well as on things like domestics, bulky lower-priced items, again, where the freight cost is significant. Some deflationary items were as much as 20% to 30% and, again, mostly freight-related," he added.

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