This month, there are some clinical results for a mucosal next generation Covid vaccine – the 30th mucosal vaccine on my list of mucosal vaccines that have gone into clinical trial. Plus, I’ve added over a dozen preclinical reports to my collection, including more results showing prevention of transmission or durable immunity. And an intranasal vaccine based on an agent called a STING agonist showed strong protection from other coronaviruses, as well as protection against transmission.
News from US Project NextGen
As well as funding trials of next generation Covid vaccines, Project NextGen is funding research on the correlates of protection from authorized vaccines (studying levels of antibodies etc associated with effective vaccination). To try to ensure a group of participants that is more diverse than is usual for clinical trials based in hospitals and universities, they announced this month a pharmacy-based initiative to broaden access. About 20 Walgreens pharmacies in urban, suburban, and rural areas will be clinical trial sites, and “To recruit study volunteers, Walgreens will provide information on how and where to participate in the study.”
This decentralized trial will also get technical and other support from the Fred Hutch Cancer Center – and the Center has also been funded to support some of the next generation vaccine trials.
In other Project NextGen news, Castlevax – who will be running one of the phase 2b “mini-efficacy” trials for their intranasal vaccine – announced they received additional funding for that trial.
Finally, last update, I reported that a mucosal vaccine developed by the NIH’s NIAID was entering a phase 1 trial. Soon after, the NIH announced that recruitment had begun, and that this was the first Project NextGen-funded clinical trial.
Mucosal vaccine news
This month, I added a 30th mucosal vaccine that has gone into clinical trial. (I missed this one when it went into a clinical trial in China last year.) It’s an intranasal viral vector vaccine called Ad5-S-Omicron BA.1, based on adenovirus 5, and Omicron. The developers reported some results for 8 people in the phase 1 trial, along with a transmission study in mice.
The people in the clinical trial had been vaccinated with other vaccines at least 6 months before getting 2 doses of nasal spray. The developers tested their people’s blood and nasal fluids to see if they showed signs of immune response to new Omicron variants.
Nasal immunoglobulin, they reported, “retained potent neutralization” against all the Covid variants they tested, though serum immunoglobulins did not for all of them.
The developers then tested the impact on mice of intranasal application of the vaccinated people’s immunoglobulin. There were 4 groups of mice getting different immunoglobulin, and a control group getting immunoglobulin from people who did not have the intranasal vaccine. The mice getting the vaccinated people’s nasal immunoglobulin “showed a significant and comparable reduction in viral load.”
More new preclinical results:
I’ve added 7 preclinical reports on results for another 5 mucosal vaccines to my collection since the last update, with one reported below in the pancoronavirus vaccine category. The others include:
Tokyo Metropolitan Institue of Medical Science and Toko Yakuhin Kogyo Co (Japan): This vaccine is a protein subunit mixed with carboxyvinyl polymer (CVP), tested intranasally in mice. The developers reported levels of longterm efficacy (at least 15 months).
Friedrich Loeffler Institute (Germany) and University of Bern (Switzerland): This report is for genome-modified live-attenuated vaccines, tested as a single intranasal dose in mice and hamsters. For one of them, unimmunized hamsters put in contact with immunized animals after a Covid challenge test had minimal viral RNA in nasal washings and no signs of the virus in organs.
Ohio State University (USA): This group developed several versions of viral vector vaccine based on 3 Covid variants. The viral vectors were measles and mumps components of the MMR vaccine. The developers reported on testing these intranasally in mice and hamsters.
Pancoronavirus vaccine news
Pancoronavirus vaccines aim to provide protection not only from variants of the SARS virus that causes Covid, but also against the next new coronavirus to spread among humans. This month, 3 vaccines have joined this category, all from the US.
NanoSTING-SN: A mucosal protein subunit vaccine from the University of Houston and Auravax (USA)
NanoSTING is the name for a mucosal adjuvant that is a STING agonist, a class of agents that can stimulate immune activity. (STING stands for stimulator of interferon genes.) Different versions of this vaccine were tested in mice and hamsters.
Hamsters got 2 intranasal doses of the SN version, and then had a challenge test with the Delta variant, along with an unvaccinated group. The vaccinated hamsters had reduced viral loads, and by day 6, no virus was detectable.
The developers did a transmission study using the SN version in hamsters. One group had sham immunization, and a group of 8 hamsters had 2 intranasal doses of SN, 21 days apart. The immunized hamsters were challenged with an Omicron variant on day 35, and a day later, each was co-housed with an unimmunized hamster.
The vaccine protected the 8 hamsters from getting sick, and only 2 showed a low amount of virus in lung and nasal tissue. No virus was detected in any of the contact hamsters. The experiment was repeated with a single intranasal dose: This also prevented transmission.
The developers tested blood from mice vaccinated with the SN version and found signs of immune response to a group of other coronaviruses, including the original SARS and MERS, as well as an alphacoronavirus.
Then, a group of vaccinated and unvaccinated mice were challenged with the original SARS. The unvaccinated mice showed signs of illness, but the vaccinated ones did not, and all survived.
Finally, the developers vaccinated 3 primates (rhesus macaques) with 2 intranasal doses, 28 days apart. Signs of immune response were consistent with those of the mice.
This is the fourth preclinical report for this vaccine – all records here.
A protein subunit vaccine from Georgia State University (USA)
Four versions of this vaccine were tested. One of them, based on the Delta variant, showed signs of protection from all the Covid variants tested. Immunized mice were also protected in challenge experiments with the Delta variant, and the original SARS.
This is the second preclinical report for this vaccine – the first is here.
A protein subunit vaccine from Baylor College of Medicine (USA)
This vaccine aims to provide protection from betacoronaviruses, and is based on components of the original SARS, MERS, and an Omicron variant. The vaccine was tested in mice. The mice showed signs of response to all of those viruses, as well as betacoronaviruses that are currently only infecting bats.