June 2023 Newsletter

Welcome to the June 2023 Newsletter for

Santa Monica Primary Care.

In this issue we will cover the upcoming vaccination season.

Fall 2023 COVID Booster (Bivalent 2.0)

With very little fanfare, Los Angeles County’s COVID-19 Emergency ended on March 31st – with the major impact being the closure of County-run testing facilities. But beyond that, not much
changes. An indoor masking mandate was lifted 13 months ago and face covering recommendations for the general public ended two months ago. In healthcare settings, masks continue to be required for healthcare workers providing direct patient care or working in patient care cares. This, however, is a Los Angeles County only requirement as at other healthcare settings in California, no masks are required whatsoever

It was certainly reasonable for the County to close testing sites as weekly testing rates are the lowest they have been (at 148 tests per 100,000 population) since May of 2020 (Figure below). At their maximum, 2745 tests per 100,000 were performed the week ending 1/11/2022.

Smoothed SARS-CoV2 Daily Testing Rate (per 100.000 population): Los Angeles Country

Free testing remains available at LA County Public Health clinics

Seasonal COVID Incidence and Prevalence

The Los Angeles Times offered this outstanding turn of phrase when reflecting on the lifting ofthe COVID Emergency:

“But just as March 2020 is now indelibly etched in our collective consciousness
— a watershed moment when daily life screeched to a — March 2023 may be
remembered as when COVID-19 officially went from top of mind to back of mind.”

From my perspective, I was concerned that we would experience another January surge as we had in 2021 and 2022 but that never materialized (Figure below)

Smoothed Daily Incident Case Rate (Per 100,000 population) of SARS-CoV2: Los Angeles Country, California for 2020(Blue),

We are now in our current and expected Spring lull in cases, seen in all years of the pandemic -although 2020 should be interpreted cautiously given that we were under shelter-in-place orders.

Current prevalence rates (active cases per 100 population) are the lowest they have been at less than 0.1% – so fewer than 1 case per 1000 individuals – since October of 2022 (Figure below).

Estimated Prevalence Rate (per 100 individuals) of SARS-CoV2: Los Angeles Country, California

Seasonal Flu Shot for 2023/2024

One common mantra that has been repeated throughout the pandemic is that of “more cases, more hospitalizations, more deaths.” This is a pattern currently holding in the inverse with death rates also now at historic lows as case rates are at seasonal lows as well. However, in 2023 with early detection from accurate home testing and widespread availability of Paxlovid, mortality rates now stand at 0.02 deaths per day per 100,000 population (equivalent to 2 deaths per day in LA County, with 10 million people). The last time mortality was this low?

The week of March 17th, 2020.

The figure below is a log transformed graph which shows more clearly just how much mortality rates have dropped

Smoothed Daily Mortality Rate (Per 100,000 population) of SARS-CoV2: Los Angeles Country, California

RSV Vaccination for those over 65

Similar to the County’s experience, we too have seen a massive decline in cases since
November 2021 when we had 29 new cases (and 5 repeat infections). Thus far in April we have had only 3 cases (2 of which were repeat infections)

Total COVID-19 Cases and Repeat Infections by Month in 2022/2023: Santa Monica Primary Care

Timing of vaccinations

This past week, the FDA amended the terms of its Emergency Use Authorization (EUA) for the Moderna and Pfizer bivalent boosters, permitting individuals 65 and older and those with underlying immunocompromise to have an additional dose (providing that it has been 4 months from the last).

In conversations with patients about this new recommendation, I’ve found myself clarifying a few aspects of the FDA’s communication:


  1. This is not a “new” booster, it is a new recommendation. The booster is identical to that originally authorized at the end of August of 2022.
  2. The Bivalent booster contains mRNA components from the original strain of
    SARS-CoV-2 as well as from the BA.4/BA.5 omicron variants. The BA.4 and BA.5 variants have not circulated since the Fall of 2022
  3. This recommendation brings the US more in line with the UK and Canada. In the UK, they have referred to the second bivalent booster as a ‘top off’ for vulnerable populations.
  4. Fall 2022 bivalent booster uptake was far higher in the UK than the US. In the UK, 65% of those 50 and over received the bivalent booster, and >80% of those over 70 received the booster. In the US, only 42% of the population over 65 had a booster dose. So some of the rationale for recommending a second bivalent booster may, in fact, be to encourage people simply to get their first.
  5. The general expectation is that there will be a new booster available in the Fall of 2023 which would be updated for circulating variant(s) at that time and also coincide in timing with an annual flu shot
  6. For now there is little compelling reason if one is young and healthy to have another bivalent booster. Individuals that are older (65 and above) with comorbidities or any immunocompromise could think about one at this point, with the context that cases and deaths are currently at historic lows.

Follow us on social media

Dr. Bretsky is active on Twitter (or X as it is now called) @santa_care as well as Facebook (https://www.facebook.com/santamonicaprimarycare) and Instagram

Follow our blog posts on: www.drbretsky.com/blog

Archived issues of our newsletter can be found at: https://drbretsky.com/newsletters/

Follow us on social media accounts for timely updates


Visit Our Website And follow Our Blog Posts

December 2023 Newsletter

Welcome to the December 2023 Newsletter for

Santa Monica Primary Care.

In this issue, we will cover end-of-year tips and some of the things we see in a
GP practice around the Holidays. Winter is the season for respiratory viruses –
specifically Influenza, COVID and RSV. We will cover these as well with lots of
colorful graphs and even maps!

December: Not The Time to Schedule a Colonoscopy (or much else!)

Gastroenterologists of any subspecialty are busiest it seems during December. My best guess is that this phenomenon is due to patients hurrying to have screening colonoscopies before their insurance premiums reset in January. Interestingly, data from anesthesia practices (Piersa et al. 2021. Anesthesiology 135:804-812) show a 20% increase in daily caseloads during the month of December. In three years of data analysis (2017-2019), up to 24.5% more colonoscopies were performed per day in December than January through November


Gastroenterologists are not the only subspeciality that experiences this end of year rush and it does raise legitimate concerns about the availability of specialists for time sensitive and urgent cases – and not only at the end of the calendar year. It is part of a larger overall trend that I have observed with subspeciality wait times sometimes becoming unacceptably lengthy. Average wait times nationwide to see a Dermatologist average over 30 days, for Orthopedics over 2 weeks (55 days in San Diego!), and Cardiology 26 days (link: https://www.medicaleconomics.com/view/appointment-wait-times-drop-for-family-physicians-indi cating-shift-in-care).

One potential ‘fix’ to this phenomenon would be to have health insurance coverage run from July 1st until June 31st rather than from January 1st to December 31st. In this way, patients who have met their deductible would be scheduling procedures such as screening colonoscopies during the middle of the summer when sick visit rates are lower. The end of the calendar year is
always a busy time for medical practices as illnesses increase, hospitalizations increase and patients are left trying to fit in elective procedures.

COVID-19: Historically Low Rates Continue in Los Angeles (and Santa Monica)

While the Los Angeles Times recently raised concerns about a ‘tripledemic’ of COVID, flu and RSV (link: https://www.latimes.com/california/story/2023-12-05/covid-flu-rsv-on-the-rise-in-california-is-anot her-tripledemic-coming) objective data from Los Angeles County suggests that one part of that trio is not increasing. In fact, current COVID-19 rates are 65% lower than they were in the late summer and 80% lower than they were at the beginning of the year (Figure 1 below).

Smoothed Daily Incident Case Rate (Per 100,000 population) of SARS-CoV2: Los Angeles Country, California

One critique of these low rates is that most people are testing at home (if at all) so the numbers reported by the county really are not representative of the true case rate. However, using prevalence estimates (prevalence defined as the percentage of the population with an active COVID infection, calculated as a function of observed case rates, testing rates and positivity rates), we see a similar pattern with low current prevalence rates as well (Figure 2 below).

Estemated Prevalence Rate (per 100 individuals) of SARS-CoV2: Los Angeles Country, California

The most recent County-wide prevalence estimate for the week ending 11/28/2023 is 0.3% or, in other words, 3 discernable (not necessarily infectious) COVID cases per 1000 individuals.

Here at Santa Monica Primary Care, we are seeing far fewer cases than we did a year ago. Whereas in November 2022, we had 29 cases in the practice, this November we had only 6 (Figure 3 below). This extends a year-long trend wherein we have consistently seen, with the exception of September, fewer cases each month of 2023 as compared to 2022.

Total Cases of COVID-19 by Month: Santa Monica Primery Care

This may be a function of widespread blended immunity from vaccination and
community-acquired infection. General seasonal trends remain wherein we experience a large Winter (December/January) surge followed by a quiet Spring and then a mid to late summer smaller surge in cases. Historically we have seen an uptick in COVID cases after the Thanksgiving and December Holidays, so I think we can reasonably expect that this will again occur although it has not, as yet, become obvious.


The second virus of the aforementioned ‘tripledemic’, influenza, is increasing as would be expected for this time of year. Currently, 6.8% of viral cultures sent to clinical laboratories have been positive for influenza, and 4% of outpatient visits nationally have been for influenza or influenza-like respiratory illnesses. The Southeast and South-Central areas of the country are reporting the highest levels of activity (Figure 4 below).

Of the strains isolated, 74% were H1N1 and 26% were H3N2. For those that follow my monthly newsletter, we covered the selection process for seasonal influenza vaccine components in the October newsletter. Indeed, H1N1 as well as H3N2 subtypes are in the 2023/2024 formulation. So it is reassuring to see that the vaccine matches the predominant circulating subtypes. This bodes well for this season’s shot to be effective against infection entirely and more certainly in the reduction of severe disease.

RSV: Vaccination and National Trends of the Infection

Interestingly, most of the vaccination questions I have had this season have been about the RSV vaccine. To recap, there are two RSV vaccines approved for use in the United States for those 60 and older: RSVPreF3 (GSK / Arexvy) and RSVpreF (Pfizer / Abrysvo). In the UK only Arexvy has been approved for use for those over the age of 65 as the data presented by GSK are far clearer and a demonstrated 82% efficacy for Arevxy as compared to 67% for Abrysvo. Both vaccines work by stimulating an immune response against the Fusion protein (the F of the PreF and F3) that allows the virus to fuse to a host cell (yours!) and release genomic RNA into it. Blocking this protein prevents the virus from infecting cells. The vaccines themselves are expected to last over several seasons, although the observed efficacy of each declines over
time. For example, Arevxy dropped from 82% to 56% from Season 1 to Season 2.

Seasonal trends are not difficult to discern in this CDC graph beginning December 2021 and extending through in the last week of November 2023 (Figure 5 below).

Antigen Detections and PCR Detections: RVS, United States December 2021 through November 2023

RSV seasonality is typically November through March in the United States although in 2022 cases began an upward trend in September, before peaking in mid-November. Cases began trending upwards later in 2023 with the first rise occurring in October. Cases are far lower now than they were this time last year.

Paxlovid Rebound

I have been a proponent of Paxlovid administration for acute COVID since it first came on the market. There are a couple of reasons for this. Firstly, Pfizer trials have shown that Paxlovid administration within 5 days of symptoms reduced hospitalization and death by 86% amongst unvaccinated patients. Secondly, a September 2022 CDC study showed a 51% lower hospitalization rate within 30 days of infection amongst those who had received a primary mRNA vaccine series and at least one booster. Lastly, a VA study showed a nearly 30% risk reduction in long COVID for those patients who received Paxlovid as compared to those that did not (link: https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2802878).

However, it had long been my experience that COVID rebound associated with Paxlovid treatment (defined as a recurrence of symptoms and receiving a positive test after having the disease and then testing negative) was far higher than initial manufacturer estimates. Whereas Pfizer estimated a rebound rate of 2.3% with Paxlovid, a recent study published November 13th, (link: https://www.acpjournals.org/doi/10.7326/M23-1756) found that 20.8% of patients treated with Paxlovid experienced a rebound as compared to 1.8% of those receiving placebo.

The 20.8% is remarkably close to the rebound frequency we have seen here at Santa Monica Primary Care. Of 121 patients we have treated with Paxlovid, 24 (19.8%) reported a clinical rebound, typically about two weeks after treatment, Interestingly, rebound phenomenon appeared to cluster in our experience (Figure 6 below).

Paxlovid Rebound  Percent (%) by Month: Santa Monica Perimary Care,  2022-2023

The highest rates of rebound were seen in the Spring and Summer of 2022. During this time BA.1, BA.1.1 and BA.2 followed by the KBB sublineages of Omicron emerged. As compared to its Delta predecessor, Omicron multiplied 70 times faster in lung tissue but led to less severe disease. Perhaps rebound frequency is related to the circulating variant. In 2023, we had generally good results with Paxlovid with no reported rebounds until recently we have seen them reoccur in the months of July and October.

Follow us on social media

Dr. Bretsky is active on Twitter (or X as it is now called) @santa_care as well as Facebook (https://www.facebook.com/santamonicaprimarycare) and Instagram

Follow our blog posts on: www.drbretsky.com/blog

Archived issues of our newsletter can be found at: https://drbretsky.com/newsletters/

Follow us on social media accounts for timely updates


Visit Our Website And follow Our Blog Posts