Santa Barbara Doctors ExtraCare – November 2020 Newsletter

November 2020 ExtraCare Newsletter

It’s hard to believe that the holidays are fast approaching. As we prepare to gather with friends and family we thought it would be helpful to provide some useful tips on how to do it safely. In addition we highlight breaking news on Pfizer’s vaccine progress and discuss the emerging concepts of viral load and neutralizing antibodies in the fight against COVID.

• If possible, quarantine for 14 days prior to gathering with loved ones, especially if gathering with high risk individuals
• If quarantine is not an option, then consider getting COVID tested prior to gathering. (PCR test is best, we can help you get it scheduled through PDL)
• Keep the gathering as small as possible (10 or less is ideal)
• Try to spend as much time outdoors as possible (don’t forget the heaters and lights)
• Wear a mask when indoors except when eating
• Space tables and chairs as far away as possible

We wish you all a safe and Happy Thanksgiving!

COVID-19 Update : Viral load and Neutralizing Antibodies

This past month has yielded hundreds of publications related to COVID-19 with a few catching my attention and bringing me hope that we may, sometime soon, have innovative treatment strategies to combat this deadly virus.

The first study, published in the Annals of the American Thoracic Society, is a retrospective analysis of hospitalized COVID-19 patients during the height of the pandemic in New York City in March and April. Using RT-PCR testing techniques, the authors were able to measure the amount of detectable virus, or viral load, of the patients and separate them into three categories, low, intermediate and high. They showed that the patients with the high viral loads were sicker at presentation, and were almost twice as likely to die or be placed on a ventilator. This risk was independent of age, other medical conditions or severity of illness at presentation.

The second study, published in the Journal of Hospital Medicine, also looked at hospital data from New York from March to August of 2020. They found that the adjusted mortality rate dropped each month, from 25.6% in March to 7.6% in August. (Remember these are hospitalized patients, not all COVID cases). The authors went on to hypothesize that the reasons for this incremental improvement in outcomes are likely a combination of increasing clinical experience, decreasing hospital volume, growing use of new pharmacologic treatments (such as systemic corticosteroids, remdesivir, and anticytokine treatments), nonpharmacologic treatments (such as placing the patient in the prone position, or proning, rather than on their back), earlier intervention, community awareness, and, potentially, lower viral load exposure from increased mask wearing and social distancing.

Yes, it’s true. The CDC has finally updated their report on mask benefits acknowledging that masks will not only protect those around you from getting exposed to your exhaled droplets but will also reduce your exposure to infectious droplets through filtration.

So this brings me to the last couple of publications that I wanted to highlight regarding Neutralizing Antibodies and their role in reducing viral load. Neutralizing antibodies are able to bind to a particular protein on the virus, and in the process, render the virus incapable of infecting cells. Patients infected with SARS-COV-2 naturally develop neutralizing antibodies in response to their infection which is the basis for using convalescent plasma to treat hospitalized COVID-19 patients. Two pharmaceutical companies, Eli Lilly and Regeneron, released preliminary data this month on their virus neutralizing monoclonal antibodies. Both showed promising results including reduction in viral load, reduction in medical visits (including hospitalizations) and a lower symptom burden.

If these preliminary data are indicative of final outcomes data then monoclonal neutralizing antibodies will soon be another weapon in our arsenal to fight COVID-19.

https://www.atsjournals.org/doi/pdf/10.1513/AnnalsATS.202008-931RL
https://www.journalofhospitalmedicine.com/jhospmed/article/230561/hospital-medicine/trends-covid-19-risk-adjusted-mortality-rates
https://www.nejm.org/doi/full/10.1056/NEJMoa2029849
https://newsroom.regeneron.com/news-releases/news-release-details/regenerons-covid-19-outpatient-trial-prospectively-demonstrates

The Race for the Vaccine

This week brought light to a vaccine candidate (BNT162b2) that not only shows a favorable safety profile, but also remarkable efficacy.  By joint collaboration between the pharmaceutical powerhouse, Pfizer, and the German biotech company, BioNTech, preliminary results were reported to the media this week for an RNA-based Covid-19 vaccination that has surprised and rattled the scientific community.  This was a shining light amidst public setbacks of 2 other vaccine trials from AstraZeneca and Johnson & Johnson, both of which were paused over vaccine safety concerns.

Work on the vaccination began in January with a messenger RNA that, when injected into muscle cells, built a protein found on the surface of Covid-19 that was shown to be highly “immunogenic”, or rather capable of mounting a robust immune response.  This research was extended to the mouse model confirming a powerful T cell, B cell, and antibody response in the host.  In mid-March, BioNTech entered a partnership with Pfizer to launch human trials in ethnically and racially diverse populations of the United States, Argentina, Brazil, and Germany.

The race for a vaccine progressed to a Phase 3 clinical trial that initiated late July with enrollment of over 44,000 participants to date with the primary efficacy endpoint being confirmed Covid-19 cases at least 7 days following the second dose.  The full study design is transparent on the Pfizer website (https://www.pfizer.com/science/coronavirus) with the plan to continue data collection until 164 cases of Covid-19 are confirmed, the minimum threshold to provide appropriate statistical power to the study.

The first interim analysis took place just recently, after 94 people in the study tested positive for Covid-19.  All participants were randomized/blinded, and either received the vaccine or placebo; of those that tested positive for infection over 90% had received placebo, implicating a 90% vaccine efficacy. 

To put this number in perspective, the FDA was hoping to yield a vaccine at least 50% efficacious.  The seasonal flu vaccination averages an efficacy of about 40%, and the measles vaccination, which has been widely touted as a wonder of medicine, has been shown to be 93% efficacious.  If follow up statistical analyses yield similar results, and 2 months of safety is confirmed per FDA guidelines, this vaccine could be a game changer in the fight against coronavirus.    And with the backing of Pfizer, mass production is already underway, with current projections to produce 50 million doses by the end of the year, and up to 1.3 billion doses by the end of 2021, globally.  Realistically, commercial availability for the US medical system would be expected around Spring.

Recently released data from Pfizer will be peer reviewed upcoming, but one fundamental question that is still unknown is how long immunity can last with this vaccination, and this is why following subjects for at least 2 years is so critical.  A waning antibody response is seen in patients with primary Covid-19 infection as well, but long-term analysis is needed to gauge if this 2 dose vaccination series will become a yearly recommendation, akin to influenza.  Its safe to say, however, that a safe, effective vaccination is truly the missing link to breaking the momentum of this pandemic.

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