COVID booster: vaccine news and game theory

A toolkit to speed up vaccine development and research

An international team, including researchers from Griffith University, Queensland, have developed a toolkit designed to assist and expedite research into COVID-19.

The toolkit includes:

• A SARS-CoV-2 reverse genetics system, taken from the original virus genome sequences in Wuhan. This will allow researchers to easily examine individual mutations, or combinations of mutations, in the lab.
• A panel of nearly all the antibodies generated against SARS-CoV-2. This will allow virologists and immunologists to quickly see the staining from most SARS-CoV-2 proteins.
• A panel of virus isolates and cell lines from patients around the globe. These samples of virus and cells from various patients will allow researchers to test a variety of drugs against COVID-19 in vitro.

The researchers have so far delivered over 200 toolkits to laboratories around the world. They’ve published details of the toolkit in the open-access journal PLOS Biology.

“Our tools are being shared and used and are likely to feature in future SARS-COV-2 studies,” says Ali Zaid, a research fellow at Griffith University who is the co-lead author on the paper.

US approves relaxed storage for the Pfizer vaccine

One of the major challenges in the Pfizer vaccine rollout is that it needs to be stored at -80°C, which is much colder than traditional medical storage. But the US Food and Drug Administration (FDA) has just approved the storage of the vaccine at warmer temperatures, based on data provided by Pfizer.

Pfizer’s new factsheet suggests that the vaccine can be stored between -25° and -15°C for up to two weeks: this is a common temperature range for pharmaceutical freezers.

“The alternative temperature for transportation and storage will help ease the burden of procuring ultra-low cold storage equipment for vaccination sites and should help to get vaccine to more sites,” says Peter Marks, director of the FDA’s Centre for Biologics Evaluation and Research.

Longer break between doses for the Oxford-AstraZeneca vaccine

And in yet more vaccine flexibility news, it seems the Oxford-AstraZeneca vaccine is more effective when there’s a longer interval between doses.

A paper published in The Lancet describes randomised controlled trials with more than 17,000 participants, carried out in the UK, Brazil and South Africa. The authors found that a three-month gap between first and second dose of the vaccine could result in up to 81% efficacy, compared to 55% efficacy with a six-week gap.

They also found that one dose of the vaccine was 76% effective at preventing COVID-19 infection for the first three months after administering. This means it provides some protection to people not yet fully vaccinated.

The authors suggest this could be useful for distributing the vaccine in its early stages.

“Vaccine supply is likely to be limited, at least in the short term, and so policy-makers must decide how best to deliver doses to achieve the greatest public health benefit,” says Andrew Pollard, lead researcher on the study. 

“Where there is a limited supply, policies of initially vaccinating more people with a single dose may provide greater immediate population protection than vaccinating half the number of people with two doses. In the long term, a second dose should ensure long-lived immunity, and so we encourage everyone who has had their first vaccine to ensure they receive both doses.”

Game theory might be useful for studying viral infection

A paper published in the Royal Society Interface suggests that a game-theory approach may assist in understanding how COVID-19 and other viruses get into the cells.

The analysis is based around the ecological idea of “mimicry”: when an organism changes its form to represent another.

Naturalists have described various types of mimicry for decades. Examples include “Batesian” mimicry, where an organism copies another with the intent to deceive (think harmless animals that look like venomous counterparts), and “Muellerian” mimicry, where there is a common interest between organism and copier (think animals adopting each other’s warning cries).

This theory of mimicry can also be used at the molecular level: both with viruses that look like normal cells, and vaccine components that look like viruses.

The authors created a mathematical model that mapped out how a virus and a vaccine could operate in the human body. This could be useful in assisting with vaccine design.

“We need new models and technologies at many levels in order to understand how to tame viral pandemics,” says Bud Mishra, one of the paper’s authors.

More reasons for New Zealand’s pandemic success

A piece published in Nature Immunology has identified scientific expertise as the core tenet of New Zealand’s success when handling the COVID-19 pandemic.

The authors argue that decisive government leadership, informed by a range of scientific fields, allowed New Zealand to avoid the major health impacts of the disease.

Some key features of New Zealand’s success were rapid in-house PCR tests, antibody testing and viral genomics.

The government’s decisions, based on clear scientific advice, pursued a strategy that successfully kept COVID-19 from the population. NZ has recorded just over 2370 cases of COVID and just 26 deaths.

A few days after the publication, NZ prime minister Jacinda Ardern announced a week-long lockdown for the country’s largest city, Auckland, based on symptoms a 21-year-old man had presented. According to reports the man is the older sibling of a student at an Auckland high school to which several cases have been linked.