COVID Booster: extra vaccine shots, 3D images of SARS-CoV-2, and spotting allergens

No boosters for the general population just yet

There is currently no need for booster vaccine shots among the general population, a global study has found.

The review in The Lancet, run by the World Health Organisation and written by a worldwide panel of experts, found that vaccines remain highly effective against symptomatic disease, even the Delta variant. And it’s wiser to use existing supplies on unvaccinated people.

“Taken as a whole, the currently available studies do not provide credible evidence of substantially declining protection against severe disease, which is the primary goal of vaccination. The limited supply of these vaccines will save the most lives if made available to people who are at appreciable risk of serious disease and have not yet received any vaccine,” says lead author Dr Ana-Maria Henao-Restrepo, a WHO researcher.

“Even if some gain can ultimately be obtained from boosting, it will not outweigh the benefits of providing initial protection to the unvaccinated. If vaccines are deployed where they would do the most good, they could hasten the end of the pandemic by inhibiting further evolution of variants.”

SARS-CoV-2 mapped in three dimensions

A team of Australian researchers has put together a detailed map of all SARS-CoV-2’s proteins, including how they can vary and get into human cells. The researchers say their Aquaria resource has revealed new targets for viral treatments or vaccines.

A star shaped protein
The SARS-CoV-2 envelope protein as modelled in Aquaris. Credit: Aquaria.

“Our resource contains a level of detail of SARS-CoV-2’s structure that is not available anywhere else. This has given us an unprecedented insight into the virus’s activity,” says lead researcher Sean O’Donoghue, from the Garvan Institute of Medical Research and CSIRO’s Data61.

The researchers found several proteins that hijack human cells or mimic human proteins, each of which could potentially be used to combat the virus.

“Much of the coronavirus research to date has focused on the spike glycoprotein, which is the main target for current vaccines. This protein will continue to be an important target, but it’s also important we broaden our focus to other potential targets and better understand the entire viral lifecycle,” says O’Donoghue.

A paper describing their research is published in Molecular Systems Biology.

Possible culprit for rare mRNA reaction

There have been rare instances of people with anaphylactic reactions to COVID vaccines – this is one of the main reasons you have to wait under medical observation for 15 minutes after getting your jab.

A group of US scientists has found the possible reason for this allergy in mRNA vaccines: polyethylene glycol, or PEG, which is used to coat the mRNA and prevent it from disintegrating before it hits our cells.

The researchers undertook allergy testing on 11 people who’d had an anaphylactic reaction to an mRNA vaccine. Of these, all but one reacted to PEG, which suggests that it might play a role.

In their paper, published in JAMA, the researchers stress that their study group is tiny – reactions to these vaccines are rare, after all – so it’s difficult to draw firm conclusions about allergies to the vaccines.

If you’d like to read about all – yes, all – of the ingredients in COVID vaccines and what they do, this highly respected publication has you covered with this article.

Australian healthcare staff are less enthusiastic about work

An unsurprising but important study by Edith Cowan University found that 42% of Australian healthcare workers are less willing to work than before the pandemic.

The researchers surveyed nearly 600 frontline healthcare staff during the first wave of COVID-19. While they stress that sentiment may have changed since early 2020, workers’ primary concerns were availability of personal protective equipment, risk to family members, and contracting the virus.

“Organisations may have improved their processes and procedures from what they were at the start of the pandemic, but we have to weigh this against factors such as fatigue and burnout,” says Associate Professor Erin Smith, a researcher at ECU.

“As the pandemic continues, the risks of ongoing physical, psychological and emotional toll on frontline workers and their families are of great concern.”

The full results of the survey are published in Disaster Medicine and Public Health Preparedness.

Modifying Moderna to mitigate variants

While the WHO reiterates that boosters aren’t necessary for the world’s population right now, vaccine manufacturers are still interested in exploring their potential. A small trial run by Moderna has found that booster shots of its mRNA vaccine, modified to address SARS-CoV-2 variants, are safe and provoke an extra immune response in people.

The trial is still going, but interim results from 80 participants, published in Nature, show that both the original vaccine and boosters modified to mimic variants are safe for people to take. They also provoke antibodies against wild-type COVID and the Beta, Gamma and Delta variants.

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