COVID-19 vaccines: From nose drops to an overhaul, what 2023 could hold

Several vaccine companies say they expect breakthroughs as early as this year as they research new ways to protect people against SARS-CoV-2, the virus that causes COVID-19[feminine].

The Food and Drug Administration is set to convene a panel of its external vaccine advisers later this month to weigh key questions about the future of COVID-19 vaccines, including when and how to fire the shots. green to new boosters and change the strain targeted by vaccines.

Here’s a look at what’s expected this year for the next generation of COVID-19 vaccines.

New vaccines by nose or by mouth

Several companies have pursued approaches that could provide better protection against infections on their own, instead of simply mitigating the severity of the disease.

Potential vaccines to build this kind of ‘mucosal immunity’ aim to deliver antibodies to fend off the virus at sites where it first enters the body, through vaccines that could be taken as drops, sprays or pills.

A few of these vaccines have been licensed in other countries, but none in the United States — and the data behind them aren’t strong, said Dr. John Beigel, associate director of clinical research at the National Institute of Allergy and Infectious Diseases.

Even if Congress acceded to the Biden administration’s request to devote resources to developing potential next-generation mucosal vaccines in large clinical trials, Beigel said it would be difficult to “pick winners” for support. of the government.

Scientists have ways to measure immune responses after mucosal vaccines, just as they do with current vaccines. But they don’t necessarily know how those numbers will actually translate into real protection against the disease.

Different companies have researched mucosal vaccines for COVID, but the data is small and fragmented, Beigel said, using different methods and references. This makes it difficult for scientists to compare early results from labs that have tested new vaccines on animals.

“I think what needs to happen is a much more organized platform where we start to assess some of the most promising and figure out how to measure, how to figure out which of them are most likely to be successful,” Beigel said. .

One of the few mucosal vaccines to have reached the final stage of clinical trials to date is an intranasal option produced by the company Codagenix. A large study supported by the World Health Organization on the vaccine, administered by drops in the nose, should announce its results by the end of the first quarter. A booster vaccine trial was also launched last year in the UK.

Company CEO J. Robert Coleman was optimistic about the vaccine’s chances of entering the US market and said what sets his vaccine apart from the rest of the field is the prospect of data showing its direct efficacy.

Another possible mucosal vaccine could soon be heading towards what is called “provocation tests” taken like a pill, says Vaxart CEO Sean Tucker.

His company signed a deal with British company hVIVO in June to develop the “world’s first human challenge model Omicron”, which will deliberately infect vaccinated volunteers with the virus in hopes of accelerating their discoveries. hVIVO is currently working to validate the results of their approach, Tucker said.

“They haven’t announced their timeline as to when they’re going to complete this, but, assuming all goes well, it happens this year, and we could potentially evaluate our vaccine this year or next year,” Tucker said.

Regulators in China have approved CanSino Biologics repackaging their old vaccine into a nasal spray. India has also given the green light to an option produced by Bharat Biotech. Ocugen, the U.S. sponsor of this vaccine, hopes to initiate trials that could pave the way for deployment in the U.S. market.

“We would like to make Ocugen’s mucosal vaccine available as soon as possible and are seeking government funding opportunities to support the development of OCU500,” Ocugen spokeswoman Tiffany Hamilton said in an email.

However, scientists and US officials have expressed skepticism about these already-licensed options, given that an attempt by AstraZeneca and the University of Oxford yielded disappointing results last year.

“Nor is it at all clear from well-controlled clinical trials that administering existing vaccines intranasally (as some countries have even already approved) will provide a truly significant benefit on the existing generation” , the authors wrote from a viewpoint co-authored last month by Dr. Peter Marks, the FDA’s top vaccine official.

Changes to existing vaccines

Novavax and Moderna, as well as Pfizer and BioNTech, say they are pursuing clinical trials of versions of their COVID-19 vaccines mixed with components designed to trigger immunity against influenza or RSV in a single shot.

The current batch of updated “bivalent” COVID boosters are already a kind of combination vaccine, mixing an antigen intended for the original strain of the virus with another designed for the Variants BA.4 and BA.5.

“A combined flu and COVID vaccine – which still seems very optimistic about its availability for next season, and I think it could do something good to combat the vaccine fatigue that exists at the moment,” says Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center.

Some traditional vaccine makers have also announced plans for revisions that they hope can improve the duration or extent of immunity offered by current vaccines. Pfizer and BioNTech launched a study in November targeting “spikeless proteins” commonly seen in the variants.

“I’d like to think we’re not going to keep looking for variants. I’d like to think we’re not going to recommend an annual vaccine, which I don’t think makes sense either. The model flu doesn’t make sense for the coronavirus,” said Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia. He was one of two votes against the vaccine update for BA.4 and BA.5 in June.

Nowadays, an increasing proportion of infections are caused by a “recombinant” descendant of the known BA.2 strains as XBB.1.5. Updated boosters should offer “some” best protection against it, says the FDA.

“I don’t think the goal is to try to protect against mild illness,” added Offit, who said he was skeptical that immunity from infection or vaccinations would ever be. capable of blocking the onslaught of immuno-evasive strains.

The regulator should tackle the immediate question of which strains should be targeted by vaccines, as much of the country’s current “monovalent” supply is about to expire.

“If we only vaccinate against viruses that are currently circulating, will they be more likely to be infected by those that were present at the start of the pandemic and are no longer present?” said Dr. Stanley Perlman of the University of Iowa.

Perlman, who is also a member of the FDA’s vaccine panel, said he’s not sure if components targeting the original strain are still needed.

“I know I was more of a fan of a bivalent vaccine that was decided in June,” Perlman said. “But now I don’t know. I think we just have to see how the virus evolves.”

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