Sinopharm's COVID Booster Reverses Antibody Decline, Enhances Cell-Based Responses

In this Feb. 8, 2021 file photo, a man receives his Sinopharm COVID-19 vaccine from a medical staffer at Guru Nanak Darbar temple in Dubai, United Arab Emirates. (AP)
In this Feb. 8, 2021 file photo, a man receives his Sinopharm COVID-19 vaccine from a medical staffer at Guru Nanak Darbar temple in Dubai, United Arab Emirates. (AP)
TT
20

Sinopharm's COVID Booster Reverses Antibody Decline, Enhances Cell-Based Responses

In this Feb. 8, 2021 file photo, a man receives his Sinopharm COVID-19 vaccine from a medical staffer at Guru Nanak Darbar temple in Dubai, United Arab Emirates. (AP)
In this Feb. 8, 2021 file photo, a man receives his Sinopharm COVID-19 vaccine from a medical staffer at Guru Nanak Darbar temple in Dubai, United Arab Emirates. (AP)

A third shot of Sinopharm's COVID-19 vaccine leads to a rebound in antibody levels that drop months after a second dose, a small-scale Chinese study showed.

It also showed the booster enhanced cell-based responses to the coronavirus, reported Reuters.

The findings yet to undergo peer review, come as China starts to give a third COVID-19 shot to higher risk members of the population, as concerns grow that waning antibody levels over time could weaken protection against the virus.

The Sinopharm vaccine is among China's major inoculation tools and is also used in countries such as the United Arab Emirates and Cambodia.

About five months after a second Sinopharm dose, the average concentration of neutralizing antibody against the virus dropped by 70% from the level seen four weeks after that shot, according to analysis of samples taken from vaccinated healthcare workers.

But one week after a third shot, the antibody concentration had increased 7.2-fold compared with the level seen five months after the second shot, researchers from a hospital affiliated with the Sun Yat-sen University said in the paper.

The study on the BBIBP-CorV shot did not discuss how the changes in antibody concentration might impact the vaccine's efficacy, or how the boosted antibody works against variants of the virus.

Several other vaccines have also shown declines in antibody levels over time and their developers have used such data to make a case for boosters.

But some scientists say more data is needed to decide whether boosters are needed.

Cellular responses, another important part of the human immune system, also improved after the third Sinopharm shot, the paper said. "Both humoral and cellular responses were induced by the third dose of robustly and rapidly," researchers said, adding the cellular responses could be key for durable protection.

But two experts outside the study said the implication of the cellular readings could be limited, partly because it remains unclear how T cell-mediated responses correlate with COVID shots' protection.



Bezos-backed Methane-tracking Satellite Lost in Space

US Amazon's founder Jeff Bezos and his wife Lauren Sanchez Bezos leave the Aman Hotel for lunch a day after their wedding in Venice on June 28, 2025. (Photo by ANDREA PATTARO / AFP)
US Amazon's founder Jeff Bezos and his wife Lauren Sanchez Bezos leave the Aman Hotel for lunch a day after their wedding in Venice on June 28, 2025. (Photo by ANDREA PATTARO / AFP)
TT
20

Bezos-backed Methane-tracking Satellite Lost in Space

US Amazon's founder Jeff Bezos and his wife Lauren Sanchez Bezos leave the Aman Hotel for lunch a day after their wedding in Venice on June 28, 2025. (Photo by ANDREA PATTARO / AFP)
US Amazon's founder Jeff Bezos and his wife Lauren Sanchez Bezos leave the Aman Hotel for lunch a day after their wedding in Venice on June 28, 2025. (Photo by ANDREA PATTARO / AFP)

A satellite backed by billionaire Amazon founder Jeff Bezos has been lost in space while carrying out an important climate change mission, New Zealand officials said Wednesday.

Designed to measure greenhouse gas emissions with "unprecedented resolution", the MethaneSAT space probe was also funded by Wellington and the US-based Environmental Defense Fund.

Plagued with technical problems, the satellite recently stopped responding to its Earth-bound controllers.

"Clearly, this is a disappointing development," said Andrew Johnson, a senior official at the New Zealand Space Agency.

"As those who work in the space sector know, space is inherently challenging, and every attempt -- successful or not -- pushes the boundaries of what we know and what we're capable of."

The Environmental Defense Fund, which led the project, said it was "difficult news" but would not be the end of its methane-tracking efforts.

MethaneSAT was designed to measure emissions of the potent greenhouse gas, which fuels climate change by trapping heat in the planet's atmosphere.

It has proven notoriously difficult to get accurate estimates of the methane emissions belched out by oil and gas projects around the globe.

"It was one of the most advanced methane tracking satellites in space, measuring methane emissions in oil and gas producing regions across the world," the MethaneSAT team said.

Project lead Steven Hamburg said initial data gleaned by the satellite was "remarkable".
"Recent measurements in the Permian Basin of Texas and New Mexico revealed emissions three to five times higher than estimated by the US Environmental Protection Agency, while emissions observed in the South Caspian region are over 10 times higher than reported," Hamburg wrote on LinkedIn.

MethaneSAT was launched into space in March 2024 on the back of a SpaceX rocket fired from California.

Controllers first lost contact with the satellite on June 20, the MethaneSAT team said in a statement.

They confirmed it had lost all power on Monday this week and was "likely not recoverable".

"The engineering team is conducting a thorough investigation into the loss of communication," MethaneSAT said, according to AFP.

"This is expected to take time. We will share what we learn."

Despite its shorter-than-expected lifespan, MethaneSAT hailed the mission as a "remarkable success in terms of scientific and technological accomplishment".

Amazon founder Bezos pumped more than US$100 million into the project through his philanthropic Earth Fund.

The satellite eventually succumbed after overcoming a string of technical glitches.
It repeatedly entered a sleep, or stand-by, mode without prompting -- forcing engineers to perform a lengthy reset each time.

One of its three thrusters also failed.