Evidence for Reduced Antibody Protection Against SARS-CoV-2 Variants

Testing and vaccination – these are the pillars on which humanity is trying to get a grip on the Coronavirus pandemic. Although it is taking longer than many had expected, it is believed that it is only a matter of time before we are all vaccinated and thus protected.

However, time is also working for the virus, which has now mutated several times, with variants B.1.1.7 from the United Kingdom, B.1.351 from South Africa and P.1 from Brazil spreading rapidly. These viruses have mutations in the so-called spike protein, the structure on the surface of the virus that is responsible for attachment to host cells. At the same time, the spike protein is also the major target of the immune response. Antibodies generated in response to SARS-CoV-2 infection or vaccination bind to the spike protein, thereby blocking the virus.

A team led by Markus Hoffmann and Stefan Pöhlmann of the German Primate Center – Leibniz Institute for Primate Research and Jan Münch of the Ulm University Medical Centre has found that the SARS-CoV-2 variants B.1.351 and P.1 are no longer inhibited by an antibody used for COVID-19 therapy. In addition, these variants are less efficiently inhibited by antibodies from recovered patients and vaccinated individuals. Thus, convalescence from COVID-19 as well as vaccination may offer only incomplete protection against these mutant viruses (Cell).

SARS-CoV-2 viruses invade lung cells in order to multiply. For the virus to enter a cell, it must first attach to the cell surface. For this, the virus uses its so-called spike protein, which is located on the viral envelope. The spike protein is also the target for therapies and vaccines aimed at preventing the virus from replicating in the body.

At the beginning of the pandemic, SARS-CoV-2 was relatively stable, but recently several viral variants have been detected and are spreading rapidly. Variants B.1.1.7, B.1.351, and P.1, which first appeared in the United Kingdom, South Africa, and Brazil, respectively, have mutations in the spike protein and some are located in areas targeted by currently used antiviral agents and vaccines.

“This is worrisome because the rapid spread of variants that might not be efficiently inhibited by antibodies could undermine our current vaccination strategy,” says Stefan Pöhlmann, an infection biologist at the German Primate Center in Göttingen. Therefore, the team led by Pöhlmann and Münch investigated how effectively the mutant viruses are inhibited by drugs and antibodies.

“We found that certain antiviral agents that block host cell entry and are in (pre)clinical development inhibit the mutant viruses just as well as the original virus. Variant B1.1.7, which is currently spreading rapidly in Germany, was also efficiently inhibited by antibodies, including antibodies induced by vaccination. In contrast, an antibody used for COVID-19 therapy did not inhibit variants B.1.351 and P.1. Moreover, these variants were less well inhibited by antibodies from convalescent or vaccinated individuals, they partially bypassed the neutralizing effect of the antibodies,” says Jan Münch.

The use of the currently available vaccines makes sense and a rapid expansion of the vaccination efforts in Germany is desirable. However, it is possible that vaccination or recovery from COVID-19 may offer reduced protection from SARS-CoV-2 variants B.1.351 and P.1.” Clinical studies must now show the extent to which this fear is true.

“Our findings show that it is important to limit the spread of the virus as much as possible until widespread vaccination is feasible. Otherwise, we risk the emergence of new variants that cannot be effectively controlled by the currently available vaccines” says Markus Hoffmann, first author of the study.

Source: German Primate Center

In Pictures: Food of Malaysia (3)

Roti Jala

Cendawan Goreng (Fried Mushrooms)

Sambal Udang

Murtabak

Asam Pedas

Lemang

Study: Even a Little Coffee in Pregnancy Could Impact Newborn’s Weight

Dennis Thompson wrote . . . . . . . . .

As little as half a cup of coffee each day might be enough to stunt the growth and birth weight of a baby in the womb, a new study claims.

Women who consumed an average 50 milligrams of caffeine per day — equivalent to half a cup of coffee — had infants that were 2.3 ounces lighter than babies born to women who didn’t drink any caffeine, researchers report.

That amount is a fraction of the daily caffeine consumption limit currently recommended by the American College of Obstetricians and Gynecologists (ACOG) and the World Health Organization (WHO), said lead researcher Jessica Gleason. She is a postdoctoral researcher with the U.S. National Institute of Child Health and Human Development.

ACOG recommends that pregnant women limit their caffeine consumption to less than 200 milligrams a day, and the WHO suggests less than 300 milligrams daily, Gleason said.

“Our results do stand out in light of those recommendations, because we’re finding that even at lower levels we are seeing these small reductions in size,” Gleason said.

“We always recommend that women discuss their caffeine consumption with their provider,” Gleason added. “Until we know more, our research does suggest that it may be prudent to limit caffeine consumption” during pregnancy.

Previous studies looking at caffeine’s effects on pregnancy relied on women to report how much they consumed daily, Gleason said.

This study took things a step further, using blood samples taken between 10 and 13 weeks of pregnancy from more than 2,000 women at 12 clinical sites in the United States, to determine their exact levels of both caffeine and its metabolite, paraxanthine.

Overall, pregnant women with the highest blood levels of caffeine gave birth to babies that were about 3 ounces lighter, 0.17 inches shorter, 0.11 inches smaller in head circumference, and about 0.13 inches smaller in thigh circumference than the infants of women with no or minimal caffeine in their bloodstream, the researchers found.

These effects on birth size and weight from caffeine are on par with those observed in pregnant smokers, Gleason noted.

“This reduction in birth weight is within the range we see in reductions of birth weight among women who smoke during pregnancy,” Gleason said, noting that smokers tend to deliver babies an average 1.8 to 7 ounces lighter than those of nonsmokers.

The findings were published online in JAMA Network Open.

But while these results are concerning, pregnant women shouldn’t rush to throw out all their coffee beans, tea bags and diet colas, said Dr. Jill Berkin, an assistant professor of maternal-fetal medicine with the Mount Sinai Health System in New York City.

The results of this study conflict with prior research, which found no significant link between caffeine and fetal growth, Berkin said.

Further, the effects of caffeine on birth size and weight observed here were not enormous, Berkin said, and so it’s hard to say whether these babies would suffer any of the long-term health effects typically associated with stunted fetal development.

These effects can include increased risk of obesity, heart disease and diabetes later in life, the researchers said in background notes.

“It was so very small, really only coming out to about 3 ounces of difference in body weight. Whether the 3 ounces has clinical impact on a baby long-term remains to be determined,” Berkin said. “We know there are poorer outcomes associated with babies that are in the less than tenth percentile for expected weight for gestational age, but not smaller reductions in potential fetal weight, so whether that’s clinically significant is really unknown.”

Berkin added that caffeine did not significantly affect one crucial measure of fetal development — abdominal circumference.

“Traditionally when looking at fetal growth, abdominal circumference is probably the most important feature of predicting which fetuses are larger and which fetuses are smaller,” Berkin said. “In the calculations that we use to determine fetal growth, abdominal circumference is weighed heavier than all the other parameters.”

There are several theoretical reasons to suspect that caffeine could inhibit fetal growth, Gleason said.

“We know that caffeine and its primary metabolite paraxanthine both cross the placenta, but the fetus lacks the enzymes to break down or clear caffeine from its system,” Gleason said. As caffeine builds up in fetal tissues, it could disrupt growth in the womb.

Prolonged exposure to caffeine could also cause blood vessels in the uterus and placenta to constrict, which could reduce blood supply to the fetus and inhibit growth, Gleason said.

Caffeine also might disrupt normal hormonal processes in fetal development, she added.

“The results of a single study are never going to allow us to make any sort of recommendations, but just this evidence alone should certainly spark additional research into low-level caffeine consumption and size at birth and growth restrictions,” Gleason said.

Birth size is not the only thing that can be affected by coffee consumption during pregnancy: Research published earlier this year in the journal Neuropharmacology found that too much coffee during pregnancy was linked to a higher risk for behavioral problems among children.

Source: HealthDay

Malaysian-style Beef Curry

Ingredients

600 g beef
1 cup water
1/2 cup oil
300 g potatoes
5 tbsp meat curry powder
6 shallots
4 cloves garlic
3 cm piece ginger
4 cups coconut milk — extracted from 1/4 coconut
3 cm piece cinnamon stick
2 cloves
1 star anise
25 g grated coconut — fried until golden and pounded
salt to taste

Method

  1. Wash the meat well and cut into bite-size pieces and drain.
  2. Blend the curry powder with 1 cup water.
  3. Pound the shallots, garlic and ginger.
  4. Heat oil and fry the pounded ingredients until fragrant. Add in the curry powder and fry further until fragrant.
  5. Add the beef with a little bit of water.
  6. Add the pounded fried coconut, star anise, cloves and cinnamon stick.
  7. Stir slowly and add the coconut milk, potatoes and salt.
  8. Simmer until the potatoes are cooked.
  9. Serve hot with cooked rice.

Makes 4 to 6 servings.

Source: Malaysian Cuisine


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