COVID-19 booster increases durability of antibody response, research shows
New research from the University of Virginia School of Medicine speaks to the benefits of a COVID-19 booster.
The new findings shed light on how mRNA boosters – both Pfizer and Moderna – affect the durability of our antibodies to COVID-19. A booster, the researchers report, made for longer-lasting antibodies for all recipients, even those who have recovered from a COVID-19 infection.
“These results fit with other recent reports and indicate that booster shots enhance the durability of vaccine-elicited antibodies,” said senior researcher Jeffrey Wilson, MD, PhD, of UVA Health’s Division of Asthma, Allergy and Immunology.
“Although only about half of the U.S. population that is eligible for a booster has received one, it is increasingly clear that boosters enhance the protection that is conferred by the primary series mRNA vaccines alone,” said UVA Health’s Jeffrey Wilson, MD, PhD. Credits: UVA Health
Tracking COVID-19 antibodies
Wilson and his collaborators looked at antibody levels following a booster in 117 UVA employee volunteers and compared those results with the levels seen in 228 volunteers after their primary vaccination series. Antibody levels one week to 31 days after the primary series and booster were similar, but the boosted antibodies stuck around longer regardless of whether the person had had COVID-19.
“Our initial thought was that that boosters would lead to higher antibody levels than the primary vaccine series, but that was not what we found,” said researcher Samuel Ailsworth, the first author of a new scientific paper outlining the findings. “Instead, we found that the booster led to longer lasting antibodies.”
Antibody levels naturally decline over time after an infection or after vaccination, but higher levels are thought to be more protective. Thus, longer-lasting antibodies would be expected to provide more sustained immunity against severe COVID-19.
The researchers found that the antibodies generated by the Moderna booster proved longer lasting than those generated by the Pfizer booster. Moderna’s antibody levels exceeded Pfizer’s out to five months, the end of the study period. Although the findings were statistically significant, Wilson notes that both mRNA vaccine boosters provide enhanced and fairly similar levels of protection against COVID-19 in recently published large epidemiologic studies.
Because the frequency of COVID-19 infections in the community was relatively high when the boosters were being given, the authors also studied the effect of COVID-19 infection on antibody levels. The findings suggest that the “enhanced antibody durability observed after booster vaccination was not explained by hybrid immunity,” the researchers report in their paper.
In the latest results, younger booster recipients initially generated more antibodies than did older recipients, but this difference disappeared with time.
Wilson notes that this study adds to the accumulating evidence that boosters are an important of protecting the community from COVID-19.
“Although only about half of the U.S. population that is eligible for a booster has received one, it is increasingly clear that boosters enhance the protection that is conferred by the primary series mRNA vaccines alone,” he said.
The research was supported by the UVA Manning COVID-19 Research Fund, an American Academy of Allergy, Asthma & Immunology Faculty Development Award and National Institutes of Health grant R37-AI20565.
To keep up with the latest medical research news from UVA, subscribe to the Making of Medicine blog at http://makingofmedicine.virginia.edu.
Press release from the University of Virginia Health System
ALMA finds possible sign of neutron star in supernova 1987A
Two teams of astronomers have made a compelling case in the 33-year-old mystery surrounding Supernova 1987A. Based on observations of the Atacama Large Millimeter/submillimeter Array (ALMA) and a theoretical follow-up study, the scientists provide new insight for the argument that a neutron star is hiding deep inside the remains of the exploded star. This would be the youngest neutron star known to date.
This artist’s illustration of Supernova 1987A shows the dusty inner regions of the exploded star’s remnants (red), in which a neutron star might be hiding. This inner region is contrasted with the outer shell (blue), where the energy from the supernova is colliding (green) with the envelope of gas ejected from the star prior to its powerful detonation. Credits: NRAO/AUI/NSF, B. Saxton
Ever since astronomers witnessed one of the brightest explosions of a star in the night sky, creating Supernova 1987A (SN 1987A), they have been searching for a compact object that should have formed in the leftovers from the blast.
Because particles known as neutrinos were detected on Earth on the day of the explosion (23 February 1987), astronomers expected that a neutron star had formed in the collapsed center of the star. But when scientists could not find any evidence for that star, they started to wonder whether it subsequently collapsed into a black hole instead. For decades the scientific community has been eagerly awaiting a signal from this object that has been hiding behind a very thick cloud of dust.
The “blob”
Extremely high-resolution ALMA images revealed a hot “blob” in the dusty core of Supernova 1987A (inset), which could be the location of the missing neutron star. The red color shows dust and cold gas in the center of the supernova remnant, taken at radio wavelengths with ALMA. The green and blue hues reveal where the expanding shock wave from the exploded star is colliding with a ring of material around the supernova. The green represents the glow of visible light, captured by NASA’s Hubble Space Telescope. The blue color reveals the hottest gas and is based on data from NASA’s Chandra X-ray Observatory. The ring was initially made to glow by the flash of light from the original explosion. Over subsequent years the ring material has brightened considerably as the explosion’s shock wave slams into it. Credits: ALMA (ESO/NAOJ/NRAO), P. Cigan and R. Indebetouw; NRAO/AUI/NSF, B. Saxton; NASA/ESA
Recently, observations from the ALMA radio telescope provided the first indication of the missing neutron star after the explosion. Extremely high-resolution images revealed a hot “blob” in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspected location of the neutron star.
“We were very surprised to see this warm blob made by a thick cloud of dust in the supernova remnant,” said Mikako Matsuura from Cardiff University and a member of the team that found the blob with ALMA. “There has to be something in the cloud that has heated up the dust and which makes it shine. That’s why we suggested that there is a neutron star hiding inside the dust cloud.”
Even though Matsuura and her team were excited about this result, they wondered about the brightness of the blob. “We thought that the neutron star might be too bright to exist, but then Dany Page and his team published a study that indicated that the neutron star can indeed be this bright because it is so very young,” said Matsuura.
Dany Page is an astrophysicist at the National Autonomous University of Mexico, who has been studying SN 1987A from the start. “I was halfway through my PhD when the supernova happened,” he said, “it was one of the biggest events in my life that made me change the course of my career to try to solve this mystery. It was like a modern holy grail.”
The theoretical study by Page and his team, published today in The Astrophysical Journal, strongly supports the suggestion made by the ALMA team that a neutron star is powering the dust blob. “In spite of the supreme complexity of a supernova explosion and the extreme conditions reigning in the interior of a neutron star, the detection of a warm blob of dust is a confirmation of several predictions,” Page explained.
These predictions were the location and the temperature of the neutron star. According to supernova computer models, the explosion has “kicked away” the neutron star from its birthplace with a speed of hundreds of kilometers per second (tens of times faster than the fastest rocket). The blob is exactly at the place where astronomers think the neutron star would be today. And the temperature of the neutron star, which was predicted to be around 5 million degrees Celsius, provides enough energy to explain the brightness of the blob.
Not a pulsar or a black hole
Contrary to common expectations, the neutron star is likely not a pulsar. “A pulsar’s power depends on how fast it spins and on its magnetic field strength, both of which would need to have very finely tuned values to match the observations,” said Page, “while the thermal energy emitted by the hot surface of the young neutron star naturally fits the data.”
“The neutron star behaves exactly like we expected,” added James Lattimer of Stony Brook University in New York, and a member of Page’s research team. Lattimer has also followed SN 1987A closely, having published prior to SN 1987A predictions of a supernova’s neutrino signal that subsequently matched the observations. “Those neutrinos suggested that a black hole never formed, and moreover it seems difficult for a black hole to explain the observed brightness of the blob. We compared all possibilities and concluded that a hot neutron star is the most likely explanation.”
This neutron star is a 25 km wide, extremely hot ball of ultra-dense matter. A teaspoon of its material would weigh more than all the buildings within New York City combined. Because it can only be 33 years old, it would be the youngest neutron star ever found. The second youngest neutron star that we know of is located in the supernova remnant Cassiopeia A and is 330 years old.
Only a direct picture of the neutron star would give definite proof that it exists, but for that astronomers may need to wait a few more decades until the dust and gas in the supernova remnant become more transparent.
Detailed ALMA images
This colorful, multiwavelength image of the intricate remains of Supernova 1987A is produced with data from three different observatories. The red color shows dust and cold gas in the center of the supernova remnant, taken at radio wavelengths with ALMA. The green and blue hues reveal where the expanding shock wave from the exploded star is colliding with a ring of material around the supernova. The green represents the glow of visible light, captured by NASA’s Hubble Space Telescope. The blue color reveals the hottest gas and is based on data from NASA’s Chandra X-ray Observatory. The ring was initially made to glow by the flash of light from the original explosion. Over subsequent years the ring material has brightened considerably as the explosion’s shock wave slams into it. Credits: ALMA (ESO/NAOJ/NRAO), P. Cigan and R. Indebetouw; NRAO/AUI/NSF, B. Saxton; NASA/ESA
Even though many telescopes have made images of SN 1987A, none of them have been able to observe its core with such high precision as ALMA. Earlier (3-D) observations with ALMA already showed the types of molecules found in the supernova remnant and confirmed that it produced massive amounts of dust.
“This discovery builds upon years of ALMA observations, showing the core of the supernova in more and more detail thanks to the continuing improvements to the telescope and data processing,” said Remy Indebetouw of the National Radio Astronomy Observatory and the University of Virginia, who has been a part of the ALMA imaging team.
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This research is presented in two papers:
ALMA observation of the “blob”: “High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta”, by P. Cigan et al., The Astrophysical Journal. https://doi.org/10.3847/1538-4357/ab4b46
The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.
The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Organisation for Astronomical Research in the Southern Hemisphere (ESO), the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).
ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.
