Next big test....

Vaccines vs. Omicron: The next big test in the coronavirus pandemic

Scientists are gathering evidence on whether existing vaccines will work, while drugmakers prepare to tailor-make new jabs.

BY HELEN COLLIS

As European countries scramble to contain the spread of a new coronavirus variant, named Omicron, attention is turning to whether existing vaccines will work against it — and whether new jabs will be needed.

One reason why scientists in South Africa raised the alert about the variant that was first identified there was due to the significant number of mutations to the part of the SARS-CoV-2 virus that many of the vaccines target.

With investigations underway into whether the vaccines remain effective, governments and public health bodies are urging citizens to maximize their protection by getting booster shots, if they are eligible, and especially for those who have not yet come forward to receive a first course.

To stop the potential spread of any new variant, “it is imperative we close the immunization gap,” Andrea Ammon, director of the European Center for Disease Prevention and Control (ECDC) said in a statement, adding that this included making booster shots available for all adults and prioritizing those over the age of 40.

Vaccine makers are meanwhile getting ready to tailor-make new jabs against the Omicron variant, should that be necessary, based on their existing technologies that have proven effective against the original strain of the virus.

Are vaccines protective?

The extent to which existing vaccines are protective against Omicron is under investigation but, according to U.K. Prime Minister Boris Johnson, there are early signs that they may not be effective in preventing transmission.

“It does appear that Omicron spreads very rapidly and can be spread between people who are double-vaccinated,” he said on Saturday.

Scientists say that, in theory, Omicron may be more able to evade the protection offered by vaccines than other variants.

That’s because vaccines in use in Europe induce a multitude of antibodies to attack sites on a part of the virus known as the spike protein, explained Wendy Barclay, a respiratory virus expert from Imperial College London.

While other variants like Alpha and Delta also have mutations to these so-called antigenic sites of the protein — other sites on the spike protein have not changed and so vaccines have remained effective.

“What's a little bit different about this variant is that it has so many changes across spike that nearly all of the antigenic sites that we know about are changed on this virus,” Barclay told journalists at a briefing.

That suggests that antibodies induced by the vaccines “will be compromised in their ability to neutralize the virus,” she said, while stressing that more research was needed to prove this theory.

Meanwhile, early indications from South Africa offer a glimmer of hope.

During a press conference on Monday, Waasila Jassat, public health specialist at South Africa’s National Institute for Communicable Diseases (NICD), said there has been a sharp increase in hospital admissions in the northern region in Guateng Province, according to tweets from SA Government News.

However, most hospital admissions are in unvaccinated people, Jassat said, adding that the highest risk of hospital admissions was among older groups with underlying health conditions.

Michelle Groome, head of the division of public health surveillance and response at NICD, said cases were highest among younger people, with ages 10 to 24 hardest hit, while there were also cases among 25-to-29-year-olds.

“What we are seeing clinically in South Africa … is extremely mild,” Angelique Coetzee, chair of the South African Medical Association, told Andrew Marr on the BBC on Sunday.

Symptoms may have been missed earlier in South Africa and Europe, she said, because they differ slightly from Delta: extreme tiredness, aches and pains, headache and a scratchy throat. “No cough and no loss of smell or taste,” she said.

In South Africa, around 35 percent of the population has been vaccinated, and 2.9 million cases of COVID-19 have been reported to date in the country of nearly 60 million, although the true number may be much higher.

Biotech mobilizes

While evidence is generated on vaccine efficacy against Omicron, vaccine makers have been quick to respond.

John Bell, regius professor of medicine at Oxford University, which co-developed an adenovirus vaccine with AstraZeneca, said the company has already developed a vaccine that targets the Beta coronavirus strain, which was also first identified in South Africa and known as B.1.351.

This strain dodged much of the protection offered by the original Oxford/AstraZeneca vaccine — to the extent that South Africa called off its immunization campaign with the jab, switching to vaccines from Johnson & Johnson and BioNTech/Pfizer.

Bell told Times Radio that Beta “is the closest strain” to the one now rapidly spreading in South Africa, “so it'll be interesting to see how that performs” against Omicron. Scientists have been working on it for six months and will finish their immunogenicity studies — needed by regulators to assess whether to approve it — next week.

If Oxford and AstraZeneca need to start from scratch to develop a new vaccine against Omicron, “it'll probably take a little bit longer than the mRNA vaccines,” he said, estimating this would take four to six months.

Germany's BioNTech and U.S. partner Pfizer have been working for months on a process to quickly make a new-variant COVID-19 vaccine and scale up production if needed, BioNTech said in a statement.

The companies could “adapt the mRNA vaccine within six weeks and ship initial batches within 100 days in the event of an escape variant,” BioNTech said. They have already developed vaccines against Alpha and Delta variants and have begun clinical trials with these jabs to collect safety and tolerability data that can be provided to regulators.

Moderna, whose vaccine uses similar mRNA technology to the BioNTech/Pfizer jab, said it is investigating several strategies to protect against Omicron.

The U.S. biotech is testing whether people given a higher dose of its booster — the same dose as the primary course — have better protection against Omicron, by analyzing samples in the lab.

It also has two new booster vaccines in development. The first targets Beta and the second targets both Beta and Delta variants. Full and half doses of both are in clinical trials and the company is “rapidly" expanding testing of blood samples to analyze the antibody response to Omicron.

In addition, an Omicron-specific booster is being developed, which could be ready for clinical testing in 60 to 90 days, the company said.

Meanwhile, Novavax, whose protein-based vaccine has not yet been authorized for use, has also begun the development of a new recombinant spike protein vaccine based on the known genetic sequence of B.1.1.529. It will be ready to start testing and manufacturing “within the next few weeks,” the company said in a statement.

In addition, Novavax said trials have shown its whole spike protein vaccine may provide protection against new variants when used as a booster, as demonstrated against Alpha, Delta and Beta in a Phase 2 study. However, it has not yet filed for a license as a booster.

A decision is expected “within weeks” in the EU and also imminently in the U.K. on its vaccine, which is currently authorized in Indonesia.