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Possible vaccines/treatment(s) for Coronavirus

For completeness, the top line 'third dose' booster results from Pfizer/BioNTech for standard dose (30µg) BNT162b2 administered around 11 months after the original standard two-dose series, which were announced yesterday.

These are the first results from their randomised, controlled COVID-19 vaccine booster trial (<10k participants, 16+ years), which demonstrated a relative vaccine efficacy of 95.6% (95%CI:89.3-98.6) to disease occurrence (during a period when delta/B.1.617.2 was dominant), consistent irrespective of age, sex, race, ethnicity, or comorbidity.

Note that the efficacy quoted is disease reduction in the boosted vaccinees relative to unboosted (ie original two-dose series only) vaccinees (all of who had no prior infection), and not relative to unvaccinated persons.

Related, a small study of BNT162b2 booster neutralisation of early wild-type, beta/B.1.351 and delta B.1.617.2 (23 US vaccinees, 18-85 years, in a randomised, placebo-controlled, phase 1–2–3 pivotal trial), that supports the above results. Here the 30µg booster was administered around 8-9 months after the original standard two-dose series. Immunoresponses more akin to that of hybrid immunity, with significant increases in neutralising immunity substantially greater than that following the original second dose, were observed.
Neutralising responses after two and three doses of BNT162b2: 50% neutralisation titres against a wild-type (USA-WA1/2020) and against beta/B.1.351 and delta/B.1.617.2.

DOI: 10.1056/NEJMc2113468.
 
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A brief review of the state of play of new variant vaccine development.

Essentially - there is no pressing need for any right now. The main players (Pfizer/BioNTech, Moderna and AstraZeneca) are engaged in dress rehearsals, practicing, tuning the entire pipeline and making sure they are in a position to move swiftly should a new variant with high degree of escape arise (ie a significant jump in hospitalised vaccinees).

To this end they have been producing small test runs of variant specific vaccines (Pfizer and AstraZeneca are testing beta variant based vaccines and Moderna is trialling a multivalent beta/delta one). But there are no plans to offer these to the public. The aim is to iron out any potential issues and streamline the process to the same degree that is seen with annual flu vaccine selection (only perhaps even faster with mRNA platforms).
 
A brief review of the state of play of new variant vaccine development.

Essentially - there is no pressing need for any right now. The main players (Pfizer/BioNTech, Moderna and AstraZeneca) are engaged in dress rehearsals, practicing, tuning the entire pipeline and making sure they are in a position to move swiftly should a new variant with high degree of escape arise (ie a significant jump in hospitalised vaccinees).

To this end they have been producing small test runs of variant specific vaccines (Pfizer and AstraZeneca are testing beta variant based vaccines and Moderna is trialling a multivalent beta/delta one). But there are no plans to offer these to the public. The aim is to iron out any potential issues and streamline the process to the same degree that is seen with annual flu vaccine selection (only perhaps even faster with mRNA platforms).
It seems to me that the Covid thing, if nothing else, has resulted in a step change in the practicalities of vaccine development.

I think the next 10 25 years is going to be very, very interesting in the world of immunology.
 
It seems to me that the Covid thing, if nothing else, has resulted in a step change in the practicalities of vaccine development.

I think the next 10 25 years is going to be very, very interesting in the world of immunology.

Partly this is true as the mRNA platform has really shined with covid and the more traditional methods were already well developed over many years. Tbh though the advantage that really helps is the strain change regulatory pathway from getting annual flu jab approvals. This will be used to tune covid jabs as and when required. It means a lot of the red tape is already streamlined so the focus can be on selecting which strains are included.

Combined flu/covid jabs would be logistically handy, and I know some trials have been done, but I’m not sure if it’ll become the norm. Time will tell.
 
Topline results comprising Moderna's interim data from the KidCOVE study. These are for an initial two-dose series of 50µg mRNA-1273 in (4,753) children, 6-11 years (half the adult doses).

Strong immunogenic responses were observed, with high seroconversion rate. The doses were will tolerated, with reaction comparable to those seen in adults. Specifically, in this trial, the SARS-CoV-2 neutralising antibody geometric mean ratio (GMR), comparing the response in children to the response in young adults from the phase 3 COVE study, was 1.5 (95%Cl:1.3-1.8), with a seroresponse rate of 99.3%.

Moderna plan to submit these data to FDA/EMA/etc in due course.
 
Novavax has just filed with the MHRA for regulatory approval of their SARS-CoV-2 NVX-CoV2373 protein sub-unit vaccine, based on their phase 3 trial results and other data. They expect to complete filings with regulatory authorities in Canada, Australia, and New Zealand, plus the WHO, shortly. US FDA submission expected towards the end of the year.
 
Back to hybrid immunity - from MIT/Harvard a preprint for a small study (n=35) investigating delta-related 'breakthrough' infection immunity response in a US community (infections typically around 5-6 months after vaccination, so possibly in the timeframe of declining antibody titres reported by previous studies; note that this study does not provide longitudinal profiles).

The data suggest that hybrid immunity (infection plus vaccination) not unsurprisingly appears to work the other way too - boosted immune responses, both humoral and cellular, are observed in subsequently infected vaccinees.
Antibody responses in COVID-19 vaccinated individuals with and without confirmed SARS-CoV-2 breakthrough infection, by vaccine type.
It's a small sample but there might be more heterogeneity in post-vaccination 'breakthrough' immunoresponses compared to earlier studies of infection-then-vaccination, and the study doesn't appear to screen earlier convalescents, so those with prior hybrid "superimmunity" might be skewing the readout slightly.

Also, the results could further be skewed somewhat as the age of the infected cohort (36-40 years) was notably lower than that of the uninfected cohort (54-66 years), quite possibly due to NPI-behaviours (think - degrees of immunosenescence). Additionally, the same 'infected' cohort might have been more likely to have been convalescents prior to vaccination for similar reasons (disposition to risk taking).
DOI: 10.1101/2021.10.18.21265113.
 
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Pfizer/BioNTech have submitted dosing/reactogenicity/immunogenicity data to the FDA for EUA consideration of a two dose 10µg BNT162b2 for 5-11 year olds (dosing interval 21 days).

At 10µg adverse reactions are very low (compared to a standard dose 30µg regimen); they are almost comparable to the placebo arm. The lower dose was observed to induce better neutralising titres than the standard dose. Efficacy to any delta/B.1.617.2 infection, one week after second dose, was 90.7% (95%CI:67.7-98.3).
Approved by the FDA and now the CDC advisory panel have just voted unanimously in favour of it.
 
Molnupiravir ( Possible vaccines/treatment(s) for Coronavirus and Possible vaccines/treatment(s) for Coronavirus ) now approved in the UK.


The first pill designed to treat symptomatic Covid has been approved by the UK medicines regulator.
The tablet - molnupiravir - will be given twice a day to vulnerable patients recently diagnosed with the disease.
In clinical trials the pill, originally developed to treat flu, cut the risk of hospitalisation or death by about half.

Molnupiravir, developed by the US drug companies Merck, Sharp and Dohme (MSD) and Ridgeback Biotherapeutics, is the first antiviral medication for Covid which can be taken as a pill rather than injected or given intravenously.
The UK has agreed to purchase 480,000 courses with the first deliveries expected by mid November.
Initially it will be given to both vaccinated and unvaccinated Britons through a national study, with extra data on its effectiveness collected before any decision to order more.
The drug needs to be given within five days of symptoms developing to be most effective.
It's not immediately clear how it will be distributed so quickly by the NHS. It's thought some care homes may be offered supplies while other elderly or vulnerable patients may be prescribed a course by their GP after testing positive for Covid.

This is exactly the sort of option which the UK establishment love. Its the sort of thing they can actually be bothered to do (eg we threw lots of tamiflu at the swine flu pandemic despite a lack of evidence it would help). Its when treatments like this arent available that the woeful nature of UK establishment thinking and response becomes so evident in deadly ways. So fingers crossed this option will actually make a real difference.
 
I'll be interested to see how they deliver it/ decide who gets it. Distribute via GP? At hospitals? Deliver it round to vulnerable people when they register positive test? Etc
 
Pfizer's oral antiviral candidate ritonavir (trade name PAXLOVID) was found to reduce the risk of hospitalisation or death by 89% compared to placebo in non-hospitalised high-risk adults with COVID-19. Ritonavir is a protease inhibitor (interferes with virus replication) originally developed for SARS-CoV-1.

Original study behind this here - DOI: 10.1126/science.abl4784.
 
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I'll be interested to see how they deliver it/ decide who gets it. Distribute via GP? At hospitals? Deliver it round to vulnerable people when they register positive test? Etc
They havnt ordered much of the stuff, perhaps in the realisation that the chances of recognising someone needs it before its too late to be of much use seem quite small in an era where medical services are so hard to access
 
Which part of 'Initially it will be given to both vaccinated and unvaccinated Britons through a national study, with extra data on its effectiveness collected before any decision to order more.' are you finding hard to understand?
 
will be given twice a day to vulnerable patients recently diagnosed with the disease.

There can be quite significant wait times for PCR diagnosis which itself is only going to be initiated after a +LFT or symptons showing
 
Which part of 'Initially it will be given to both vaccinated and unvaccinated Britons through a national study, with extra data on its effectiveness collected before any decision to order more.' are you finding hard to understand?
Ah sorry, was skimming, managed to miss that bit. Will be interesting to see outcomes, and positive, I hope.
 
Cloo, I think the dig was probably aimed at me, hence my explanation for my thoughts above
 
Bharat Biotech's whole virion (D614G backbone) inactivated SARS-CoV-2 vaccine, COVAXIN/BBV152 (previous trial results in post #1375), has been given an emergency use listing by the WHO. This will help facilitate distribution of it for COVAX and should see it accepted more widely for travel purposes.

Novavax has also just submitted to the WHO for EUL for NVX-CoV2373.
They also have preliminary data from booster trials indicating a 4-fold increase in neutralising antibodies over the initial two-dose regimen and a 6-fold increase in cross-reactive antibodies to delta/B.1.617.2. Additionally, they are about to trial their combination adjuvanted COVID-NanoFlu vaccine (a quadrivalent recombinant HA protein nanoparticle influenza vaccine combined with NVX-CoV2373).
 
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From the University of Birmingham an anti-viral nasal spray (a composite λ-carrageenan polysaccharide gel) that targets SARS-CoV-2. Aiming to be available in the UK and Asia in early 2022.
DOI: 10.1002/adma.202008304.
 
From New Scientist:
Many groups worldwide are trying to develop vaccines that protect against a wide range of coronaviruses and prevent another pandemic. These efforts have now been boosted by the discovery that some healthcare workers had pre-existing immunity to the SARS-CoV-2 virus during the first wave of the pandemic.

During the first half of 2020, around 700 healthcare workers in the UK were tested weekly as part of a crowdfunded study called COVIDsortium. Most of these people, who wore protective equipment, never tested positive for covid-19 in PCR tests or developed covid-19 – proteins that bind to the outside of viruses, preventing cells from being infected.

However, when Leo Swadling and Mala Maini at University College London and their colleagues looked more closely, they found some of those who tested negative had a protein in their blood that is linked to covid-19 infection, as well as T cell responses to the SARS-CoV-2 virus. T cells are part of the immune system. It appears these people had what Swadling calls an “abortive infection”, where a strong, early T cell response enabled them to get rid of the virus very quickly.

Cells infected by viruses sound the alarm by displaying viral proteins on their surface, and T cells are the immune cells that learn to recognise these proteins and destroy infected cells. Crucially, while antibodies can only target proteins on the outside of a virus, T cells can learn to recognise any viral proteins.

When the team looked at early blood samples from the people who had an abortive infection, they found that even before being exposed to SARS-CoV-2, they had some T cells that could recognise the proteins that this virus uses to replicate itself inside infected cells.

The most likely explanation is that these people were often exposed to the existing human coronaviruses that cause around 10 per cent of colds, says Maini. “We don’t know the historic infections of these individuals, so we don’t know for sure where the T cells are coming from,” she says.

Preventing another pandemic
The proteins involved in viral replication are very similar in SARS-CoV-2 and other human and animal coronaviruses, meaning that if vaccines can be developed that elicit a strong T cell response against these proteins, they should protect against a very broad range of coronaviruses – a so-called universal or pan-coronavirus vaccine. One way to do this would be to add mRNAs coding for these proteins to mRNA vaccines that target the virus’s external spike protein.

Adding extra components to the next generation of coronavirus vaccines might protect both against any new variants that might evolve and against animal coronaviruses that could jump into people and spark a new pandemic, says Swadling. “There is a strong rationale for adding these proteins alongside the spike protein,” he says.

Many groups are already trying to develop coronavirus vaccines that provide broader protection, says Olga Pleguezuelos at UK-based company SEEK. Her team has already created such a vaccine based on the most conserved parts of coronavirus proteins. “It’s a matter of time before another of these members [of the coronavirus family] creates an epidemic or pandemic,” she says. “If we end up with something that is as infectious as covid and as lethal as MERS, then we are in serious trouble.”

However, it isn’t clear how effective a vaccine that only produces a T cell response would be, Maini says. Most vaccines work by stimulating an antibody response, though many do also produce a T cell response.

Many groups are developing universal flu vaccines based on eliciting a T cell response, but so far these haven’t proved highly effective. Other teams are instead focusing on getting antibodies to target parts of the outer viral proteins of the flu virus that don’t mutate. However, this won’t work with coronaviruses, says Peter Palese at the Icahn School of Medicine at Mount Sinai in New York. “They just don’t have a conserved region.”

Journal reference: Nature, DOI: 10.1038/s41586-021-04186-8
 
HIPRA Labs' (Spanish pharmaceuticals company) recombinant protein vaccine PHH-1V (storable at standard refrigeration temperatures), after showing promise in safety and reactogenicity rials over the summer, has been authorised to proceed to a phase 2b clinical trial in Spain to establishing dosing and immunogenicity. If trials are successful, HIPRA hope to make it available by mid-2022. They also have a mRNA vaccine in development.
 
(Oxford) a micro-needle skin patch administered (the 'T-chip', stable at room temperature) SARS-CoV-2 T cell priming vaccine, produced by Emergex, is about to start phase 1 trials in Switzerland. This vaccine platform delivers sets of synthetic immunogenic peptides, reverse-engineered from convalescent sera, on a gold nanoparticle scaffold, to stimulate a T cell response. This vaccine is designed to act as a prime dose, with subsequent natural infection (with severe disease risk substantially lowered) acting as the booster.
 

I don’t get why he would even say this. It’s still expected to be approved, maybe even this year. Unless I’ve missed some news.
 
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