Protective Immunity After COVID-19

May 11, 2021 By Deborah Leave a Comment

The question that remains on people’s minds is how effective and long lasting the immunity is from either having had the COVID-19 infection or the vaccine. Now we are starting to get some answers. According to a population-wide study in Australia using data from the SARS-CoV-2 national infection reporting system, the re-infection rate has been low.

Researchers compared the odds of SARS-CoV-2 re-infections of COVID-19 survivors of the first wave (February- April 30, 2020) versus the odds of first infections in the remainder general population (by tracking PCR confirmed infections of both groups) during the second wave (September 1st-November 30, 2020). Out of the almost 15,000 COVID-19 survivors of the first wave and 253,000 infections in the 8.9 million individuals of the remaining general population, only 40 tentative re-infections were recorded.

This shows a relatively low re-infection rate of SARS-CoV-2 in Australia. Assuming that convalescents were exposed to COVID-19 at the same rate as people in the general population during the second wave, reduction in risk for re-infection was >90% which lasted for at least 7 months. Protection against SARS-CoV-2 after natural infection is comparable with the highest estimates on vaccine efficacies. Based on this data, there appears to be considerable protective immunity for at least 7 months after COVID-19 infection and no urgent need for booster vaccinations in COVID-19 convalescents. More well-designed research is needed for improving evidence-based public health decisions and vaccination strategies.

Reference: Pilz S et al. SARS-CoV-2 re-infection risk in Australia. Eur J Clin Invest 2021 April; 51:e13520.

Gut Microbiome Linked to Major Depression

April 22, 2021 By Deborah

I’ve published many studies linking the gut microbiome to certain health conditions. One of the conditions that has shown significant interest is mood disorders, especially major depressive disorder (MDD). Studies that have linked the gut microbiome to major depressive disorder have been small and have been met with skepticism. A recent study from China may give us more insight into the mechanism by which bacteria in the gut might influence brain chemistry. Researchers collected 311 fecal samples from people with MDD (unmedicated) and from healthy controls. Microbiome researchers were looking for a more precise picture of the organisms present versus a genus level within a batch of microorganisms.

Results found 18 specific bacterial species that were more abundant in those with MDD. They also found 3 specific bacteriophages (viruses that infect bacteria), and 50 fecal metabolites that were significantly associated with MDD verses healthy controls. The gut bacterial metabolites that correlated with MDD were molecules that are involved in amino acid metabolism. The most important pathways were related to gamma-aminobutyric acid (GABA), phenylalanine, and tryptophan metabolism. These molecules enter the blood from the gut, affect neurochemistry, and have been implicated in MDD.

Researchers point out that GABA, a neurotransmitter in the brain, is made by gut microbes. Fecal levels of GABA and some of its metabolites were decreased in the MDD patients. GABA related microbial genes were also altered in MDD patients suggesting that microbes modulate GABA levels. It is possible that this may dysregulate the function of GABA in the brain, and could lead to depressive symptoms.

Scientists also hypothesize that an increase in certain phyla called Bacteroides could increase inflammation which has been linked to MDD. Also decreased Blautia bacteria which has been shown to have anti-inflammatory effects could contribute to MDD. Other studies have found that when fecal transplanting the entire microbiota of a person with MDD into a germ-free rat, it causes “depressive-like” behaviors in the rat.

Epidemiological researchers have found that many people with irritable bowel syndrome are also depressed. Also those on the autism spectrum tend to have digestive problems, and people with Parkinson’s disease are prone to constipation. Researchers have also noticed people taking antibiotics are more prone to depression compared to those taking antiviral or antifungal medications that leave gut bacteria unharmed.

So what is the mechanism behind the actually pathway from the gut to the brain? Some substances secreted by the gut microbes may infiltrate blood vessels for a direct ride to the brain. Other bacteria may stimulate the vagus nerve, which runs from the base of the brain to the organs in the abdomen. Indirect links might also exist. Gut bacteria is so important to proper immune function and studies show that having the wrong mix of microbes can promote inflammation. Microbial products can influence enteroendocrine cells which reside in the lining of the gut and release hormones and other peptides. Some of these cells regulate digestion and control insulin production. They also release the neurotransmitter serotonin which escapes the gut and travels throughout the body. This is where our gut flora might influence weight gain, sleep and how we respond to stress.

It’s crazy to think how much influence our gut has to our mood. Depressed symptoms can influence our diet behavior which can influence our gut characteristics and composition. On the other hand, our bacteria can produce some special metabolites and have a specific pathway that can influence our brain function. More research needs to be done to determine whether any of these pathways are actually causally related to depression. Nutritional psychiatry is a new emerging field that is so exciting. We may be able to target the microbiome through diet (and specific probiotics) which could alleviate some of the symptoms of depression.

This is one more piece of evidence that shows a strong association of microbiome function and mental wellbeing.

Reference: Yang J et al. Landscapes of bacteria and metabolic signatures and their interactions major depressive disorders. Sci Adv 2020 Dec 2; 6:eaba8555.

The Psychbiome

The Disproportionate Gender Differences of COVID 19

March 11, 2021 By Deborah

Women are disproportionately effected by the complications and disease outcome of COVID-19 compared to men.

Gender-specific conditions have the potential to worsen the heart and lung damage caused by this virus. COVID-19 is a vascular disease. Women, compared to men, have smaller blood vessels, which can become dysfunctional and affect the body’s ability to deliver oxygen and nutrients to the heart. This microvascular dysfunction leads to ischemia which results in plaque erosion, clot formation and a potential cardiovascular event, such as a heart attack or stroke.

Other risk factors include polycystic ovarian disease, early onset puberty and the fact that women have higher incidences of autoimmune disease–putting them at risk for cytokine storms (hyper-responses of the immune system). Even though males have higher plasma levels of immune cytokines (immune cells called to the site of infection), women with higher levels of these cytokines were associated with worse disease progression and outcome than men.

The risks to women who have had problem pregnancies (preeclampsia, gestational diabetes) and women going through menopause are also notable. Estrogen helps prevent cardiovascular disease, and as their estrogen levels decline, menopausal women experience a higher likelihood of developing heart disease. Depression increases the risk of heart attack in women by 50% although researchers are unsure why. Severe shock can also take its toll on women. Broken heart syndrome, or takotsubo cardiomyopathy can cause fatal heart damage to mostly menopausal and postmenopausal women who have undergone a sudden stress such as losing a spouse, a car accident or being a victim of a violent crime.

Effective therapy and prevention is needed which starts with educating women in knowing their risks.

Gender differences for increased heart disease were already in place before COVID-19, but it is important to understand the increased risk factors for women that present themselves due to the nature of this virus.

https://www.nature.com/articles/s41586-020-2700-3

Marijuana and Pregnancy- Not Recommended

February 16, 2021 By Deborah

As legalization of marijuana spreads, 7% of pregnant women in the U.S. are using this unregulated drug to help reduce morning sickness. But is it safe?

In some states that legalize marijuana, dispensaries can be as common as coffee shops. Like smoking cigarettes or alcohol consumption, anyone over the age of 21 can easily walk into a store and buy a variety of compounds recreationally for their own use. But there are risks to be aware of, especially for pregnant women. Are the people behind the counter knowledgable enough to give sound advice to pregnant women seeking medical advice?

A study at the University of Colorado looked into the type of information being provided by staff members of marijuana dispensaries. Investigators posed as 8-week pregnant patients and called 465 dispensaries which resulted in useful information from 400 locations. Investigators asked employees if they had products that were “safe for morning sickness.” Other questions were about any known risks to the mother or baby with taking these products and whether they should check with their own health care provider. Results were: 69% of staff members recommended marijuana products for morning sickness, and 36% said that it was safe to use in pregnancy. Only 32% recommended that the patient check with her physician, but after prompting, 81% eventually recommended it.

This may not be happening in every state, but this study gives you a glimpse of how many pregnant women are likely not asking their provider for advice on the safety of using marijuana for morning sickness. But instead are seeking medical advice from marijuana sales people who not only have a conflict of interest and lack of medical knowledge but also a lack of cautionary approach on the topic.

Currently marijuana products contain from 0.3% tetrahydrocannabinol (THC) up to 15% and, even some concentrations up to more than 50% THC. THC acts on CB1 receptors that have psychotropic effects. Cannabidiol (CBD) acts through its effects on serotonin and not CB1 receptors for the most part. Cannabis, the marijuana plant, contains up to 100 cannabinoids with the two that we most know about described above. Dependence and addiction affects about 9% of users. This is compared to 15% of the population addicted to alcohol. This can lead to the risk of addiction to the newborn, let alone other potential consequences of cannabinoid exposure in utero.

There have been studies showing that children exposed in utero to cannabis performed more poorly in visual problem solving, motor coordination, had attention deficits and childhood sleep problems for up to a decade compared to unexposed children. Yes, thats right. According to a University of Colorado, Boulder study and lead author John Hewitt, director of CU’s Institute for Behavioral Genetics, marijuana use can impact children’s sleep long term!!

Other potential effects include increased risk of stillbirth, low birth weight (if using cannabis more than once per week) and preterm labor (those using cannabis and smoking cigarettes). A few older studies have not shown any differences in adverse outcomes with pregnant users vs nonusers. With marijuana products not being regulated and not knowing the specific ratios of THC/CBD, it can be very confusing to know what may harm mother and/or baby.

One thing for sure, marijuana use has not been proven to be safe in pregnancy. It is recommended not to use cannabis products during pregnancy-whether for recreational or medical purposes. Consult your practitioner about other safe and effective natural options for nausea and vomiting of pregnancy.

The medical use of cannabis is legal with physician prescription in 35 states. The recreational use is legal in 14 states.

Even though the use of cannabis is federally illegal, some of its derivative compounds have been approved by the Food and Drug Administration fo prescription use. For non-prescription use, cannabidiol derived from industrial hemp is legal at the federal level, but legality and enforcement varies by state. This map can identify what your state laws are regarding the use of marijuana State map of marijuana.

References: https://disa.com/map-of-marijuana-legality-by-state

Dicson, B, et al. Recommendations from cannabis dispensaries about first-trimester cannabis use. Obstet Gynecol. 2018;131: 1031-1038.

Hudson, T. Marijuana in Pregnancy-Please Don’t. Townsend Letter. Women’s Health Update. Feb/March 2019. p. 30-33.

Ultraviolet Light Can Kill the COVID-19 Virus

January 30, 2021 By Deborah

The start of 2021 is all about getting this COVID pandemic under control. Distributing vaccines as quickly as possible and continue to social distance, avoid large gatherings, wearing masks and washing our hands will be an essential part of developing herd immunity and getting our lives back to what was once normal.

Another part of reducing the presence of SARS-CoV-2 (the virus that causes COVID-19) is to find ways to destroy the virus in the environment before there is an opportunity for it to infect us. Much research has looked at the benefits behind good filtration systems and higher humidity to reduce the virulence of the virus. We are now re-visiting the benefits of ultraviolet light and its ability to kill viruses, bacteria and mold. Scientists have known about the disinfectant capabilities of ultraviolet light for decades. More than a century after Niels Finsen in 1903 won the Nobel prize for discovering that ultraviolet (UV) light could kill germs, UV light started being used in hospital rooms and other public places.

There are 3 types of ultraviolet light based on wavelength. The longest wavelengths are UV-A (315-400nm) and UV-B (280-315nm) which are found in ordinary sunlight. These rays can cause sunburn if you are outside too long without protection. They have limited germ-killing ability. But UV-C light (200-280nm) is part of the ultraviolet spectrum that can inactivate pathogens like bacteria and viruses. Because of their effectiveness, they are incredibly useful for hospitals, senior living centers, fire and police stations, schools, airports, hotels, office buildings and pretty much everywhere. So what’s the problem?

Similar to UV-A and UV-B rays from the sun, UV-C can damage the skin and eyes. You need to follow strict safety guidelines when the products are being operated. Basically, UV lamps should not be run when anyone is nearby. Trained workers should use the right personal protective equipment (PPE) and make sure products are turned off before performing maintenance. So this is maybe not as simple as screwing in a lightbulb. Disinfection with far-UVC lamps remains largely experimental but it may be safer in that it does not cause temporary skin burns and eye damage.

The other main problem is that if a surface is in shadow, it will not be disinfected. In a recently published study, a standard UV-C lamp was placed in the center of a typical hospital room and some places were partly or completely in shadow and did not receive the full dose needed to assure 99.99% disinfection. To address this problem, UVD Robots, a company based in Odense Denmark, developed a UV system that moves around the room autonomously. These robots are now available in 2000 Chinese hospitals and they are being used in more than 50 countries.

A company called Healthe has made progress on far UV-C lighting. They have developed systems that will be affordable for bars, restaurants, and other small businesses while close to eliminating the potential for spreading viruses. An LED version of UV-C may eventually be in our homes and offices. This can stop all viruses and bacteria. Can this finally be the cure for the common cold?? We will have to wait and see, but I can’t imagine a better time to push the technology envelope to help eliminate this pandemic and any future infections.

References: Lindblad M., Tano E., Lindahl C., Huss F. Ultraviolet-C decontamination of a hospital room: amount of UV light needed. Burns. 2019;46(4):842–849. [PubMed] [Google Scholar] [Ref list]

Mauldin, John. The Grip tightens. Jan 15, 2021. Mauldin Economics. https://www.mauldineconomics.com/frontlinethoughts/the-grip-tightens/

Tornberg, B. Using UV Light to kill Viruses Like COVID-19. Dec. 16, 2020. https://insights.regencylighting.com/can-uv-light-kill-viruses-like-covid-19

Mackenzie, D. Ultraviolet Light Fights New Virus. June 27, 2020. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7319933/