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Month: June 2021

Dear Dr. K; Any good news on Covid vaccines?

Dear Dr. K; Any good news on Covid vaccines?

The answer is yes: they are working well and luckily the foibles are generally mild.  Globally there are eleven different vaccines currently in use, but so far only 2% of the world’s population has been vaccinated.  We need to do better, including vaccines that don’t have elaborate requirements for transport or refrigeration.  Another 251 vaccines are at some stage of development including 60 that are entering human trials.  Let me tell you about some of the very promising ones. 

Vaxxinity Pharmaceuticals has created a vaccine using proteins from the Corona Virus spike protein that are the ones that allow the virus to attach to and invade human cells.  Another company, Novavax, has also developed a spike protein vaccine but theirs is directed to the entire protein, not just the “latch-on” portion.  Both vaccines are very promising and early trials indicate they will work against corona variants. 

Vaxart Pharmaceuticals had developed on oral vaccine that uses the common cold virus (adenovirus) to carry pieces of the corona virus through a hybrid technology.  Johnson and Johnson and AstraZeneca use the same technology in their injected vaccines which work very well. 

There are two big advantages for an oral vaccine.  One is that it is easily administered, not requiring refrigeration.  The other is a dual protection mechanism.  Oral vaccines, uniquely, provide both “blood stream” protection (as do all injected vaccines) but also mucus membrane protection.  Oral vaccines lead to antibodies being present on the mucus membranes of the nose,

mouth and lungs as a first line of defense against the virus.  Historically there was a similar segue for polio vaccines from Dr. Salk’s injected vaccine to Dr. Sabin’s oral “sugar cube” vaccine.

Another advantage of Vaxart is that it elicits an immune response to both the spike protein and the N protein on the Corona virus (Johnson and Johnson and AstraZeneca only elicit spike protein antibodies).  This may be important for mutant variants because they alter the spike protein much more rapidly than the N protein. 

Valneva Pharmaceuticals is using a killed whole virus vaccine with two adjuvants (substances that enhance immune response).  Several killed virus vaccines are already in use (made by Sinopharm, Sinovac and Bharat Biotech) but they do not include the immune booster adjuvants. 

Inovio Pharmaceuticals uses a DNA vaccine that is injected just under the skin with multiple tiny needles and then zapped into cells via a handheld wand that releases a split-second pulse of electricity.  From there the cells produce the spike protein which cues an immune response.  No other vaccine uses this delivery system.  So far, patients report much less discomfort from the vaccine and also fewer side effects.  Since the vaccine consists of only DNA and saline it can be stored at room temperature. 

Q-Tips: pollen allergy

Q-Tips: pollen allergy

We are currently in grass pollen season and soon to be added is ragweed pollen.  People with grass pollen allergy may have worse symptoms this time of year if they ingest foods that share allergenic components with the pollen.  These grass related foods are: melons, oranges, kiwi, tomato, and peanut.  Ragweed related foods include: melons, banana, artichoke, cucumber, zucchini, echinacea, chamomile and hibiscus tea.

Fluvoxamine for Covid-19?

Fluvoxamine for Covid-19?

Many drugs have been considered for treatment of Covid-19 and several monoclonal antibodies have been granted emergency use authorization by the FDA.  However, the only FDA approved drug for treating Covid-19 is the IV antiviral Remdesivir that inhibits RNA polymerase. 

Fluvoxamine is one of many SSRI’s (Selective Serotonin Reuptake Inhibitors) that are used to treat anxiety and depression.  However, Fluvoxamine is structurally unrelated to the other SSRI’s.  In addition to its serotonin modulating activity, it is a strong agonist (stimulator) of sigma-1 receptors in the endoplasmic reticulum. 

Sigma-1 receptor stimulation has been shown to limit SARS-COV-2 replication and to modulate the inflammatory response to sepsis in animals.  It is the overwhelming inflammatory response called cytokine storm that causes the life threatening acute respiratory distress syndrome in Covid-19. 

So far, two very small studies in humans have been very promising.  In a double-blind study of 152 people with Covid-19, ½ received fluvoxamine and ½ placebo.  Clinical deterioration occurred in none of the fluvoxamine recipients whereas 6 of the placebo group deteriorated. 

A second non-placebo-controlled study was done in 113 people with Covid-19.  The participants were free to choose taking the medicine or not.  Of the fluvoxamine receivers (65 in number) all were well after two weeks.  In those not accepting the drug (48 in number) six were hospitalized, two were on ventilators and one died. 

Now these are very small trials, so good science requires expanded studies.  Right now, there is a large placebo-controlled trial under way which should be completed by September.

Mother and Fetus Get Well Together

Mother and Fetus Get Well Together

Hereditary Angioedema (HAE) is an inherited deficiency of functional C-1-esterase inhibitor (C-1-INH) and is characterized by unpredictable recurrent episodes of painful often disabling swelling of the abdomen or face or extremities. 

In the recent past several new drugs have become available to treat this condition.  One of the most exciting ones is Ruconest,

which is a C-1-esterase inhibitor made by recombinant technology.  Thus, it works by replacing what the patient fails

to make (or fails to make in a functional protein).  By way of explanation C-1-esterase inhibitor is a “gate-keeper” or “watch-dog” for inappropriate activation of our complement system proteins.  If the complement system is activated when it is not needed, it makes the individual sick by causing the tissue swelling which is the hallmark of HAE.

In women with HAE, variations in hormones such as the menstrual cycle or pregnancy can bring on attacks.  A case in point was recently published in the medical literature of a 23-year-old woman who experienced multiple attacks of angioedema during her pregnancy.  Because Ruconest is technically not a drug but a pure replacement protein it is felt to be safe to use during pregnancy.   At 38 weeks the woman had a severe attack as she was going into labor.  Because of concern for the fetus an ultrasound was done and the baby was also having an attack of facial angioedema.  The woman received Ruconest and as her swelling subsided so too did her infant sons swelling.  By the time he was delivered he was back to normal.  This is the first documented account of fetal angioedema successfully treated while treating the mother.

Catnip and Mosquitoes

Catnip and Mosquitoes

Neuroscientists at Northwestern University have made an amazing discovery about catnip, it repels mosquitoes and other insects.  The active component of catnip (Nepeta catoria) is nepetalactone which stimulates a neuroreceptor called TRPA1.  TRPA1 is found in most animals from insects to humans, and transmits pain sensation to the brain.  TRPA1 can also be triggered by hot, cold, and irritants. 

The interesting thing is that when applied to humans as a repellant it does not trigger a pain response in the human, nor does it trigger pain in felines.  In felines it triggers a different receptor involved in pleasure sensation. 

Work is underway to find an effective way to use nepetalactone in an easily applied skin vehicle to provide a non-DEET alternative for summer misery.