New Information on Highly Infectious COVID-19 Strains

By Robert L. Moore, MD, MPH, MBA, Chief Medical Officer

“The tragedy of life is not in failure, but complacency.”

-Benjamin Mays

In the past week, there has been a flurry of new information about different COVID-19 strains. With large-scale community transmission, new strains can spread widely, and the most infectious strains will become more prevalent than less infectious strains over time. New information will continue to become available in the days and weeks ahead. Here is a summary of highlights:

CAL.20C: California has its own highly infectious strain of COVID-19, called CAL.20C which first appeared last summer in Los Angeles, but spread steadily since November, accounting for 30% of cases three weeks ago, and 50% of COVID-19 isolates two weeks ago in Los Angeles. This strain has now been found throughout California, including the Bay Area. Kaiser has identified it at all of their hospitals in Northern California.
This strain was incidentally discovered when California scientists began looking for the highly infectious British strain.

A laboratory director in Napa noted last week isolates of COVID-19 from community testing have much higher load of viruses in the samples than seen before in Napa. This is consistent with the mechanism for higher infectivity of these strains, which is that more virus is shed when people are infectious. Sequencing confirmation is pending, but this suggests that a more infectious strain is rapidly spreading in Northern California in larger numbers. This means that we may be looking at accelerated spread in our region in the month to come.

In the next few weeks, we will learn steadily more about this CAL.20C strain and its role in the notable big surge in COVID-19 cases in California, Arizona, and Nevada, starting in November. Specifically, we need data on mortality rates, effectiveness of vaccines, degree of increased infectiousness, and pattern of spread through the state.

B.1.1.7: On Friday, the UK government announced that early data suggests that the British variant (B.1.1.7), already known to be about 50% more infectious, may have a 30% higher mortality rate than the previous COVID-19 circulating in the UK. In the UK, this means an increase in overall mortality rate from about 1.0% to about 1.3%, still far below the mortality of coronaviruses that caused SARS in 2003 or MERS in 2012.
Early studies have confirmed Moderna vaccine effectiveness against the B.1.1.7 variant.

501Y.V2: This strain, circulating widely in South Africa, has decreased cross-reactivity to convalescent plasma and monoclonal antibodies. Today, Moderna announced that the immune response to their vaccine was somewhat less strong against 501Y.V2 than the original Wuhan strain that their vaccine is based on. We don’t know how much less clinical effectiveness (in terms of actual prevention of infection) that this translates to, but Moderna has developed a new version of their vaccine targeting this strain that it is planning on testing as a booster dose, after the original 2 dose series is completed.

P1: A new strain with over 20 mutations has been identified in Manaus, Brazil has exploded in December, 2020, even in a community which was devastated by a 60-70% infection rate in April, 2020, enough that should have generated herd immunity of the original COVID-19 strain. This raises concerns of widespread re-infection when strains of COVID-19 are sufficiently different, and makes it more likely that vaccines will be less effective against this strain. It will be weeks before we know more details.

Implications of Increased Infectiousness of COVID-19: France and Germany decided that cloth masks are not sufficient to counter spread of more infectious strains. Germany is now requiring N95, KN95, FFP2, or surgical masks, and specifically not cloth masks, for people interacting in public (like grocery stores and public transit). The original push for homemade cloth masks came from a desire to save scarce N95 masks and other masks for doctors, nurses, paramedics, doctor’s offices, etc. It is doubtful that the global supply chain for N95 masks can meet the demand to have the entire population wear them, but KN95 masks are more readily available. Absent these medical grade masks, some are calling for wearing two cloth masks, one on top of the other, to decrease risk of infection.

To increase protection against these more infectious strains, in addition to possible future changes in mask recommendations, the CDC may alter their recommendations around physical distancing. In the meantime, it might be prudent to consider a higher standard (such as 9 feet and 5 minutes instead of 6 feet and 15 minutes), in your health care settings.

Scaling Up COVID Vaccinations: Reflections on the Science of Implementation and Spread

By Robert L. Moore, MD, MPH, MBA, Chief Medical Officer

“Nearly every problem has been solved by someone, somewhere. The challenge is to find out what works and scale it up.”

-Bill Clinton, former U.S. President

In spite of several months of planning, the scaling up of the COVID vaccine has been challenging. Often, the scaling up of successful pilot programs and improvement projects encounter problems. Successful large scale implementation is a skill set not necessarily associated with good intentions, innovative thinking, or the size of the organization.

Stephen Dubner offers a nice introduction to this challenge in a Freakonomics Radio podcast, from early 2020.

In the last 10-15 years, a new social science concept called “Implementation Science” seeks to explain the factors leading to implementation challenges and how to overcome them. Several of these frameworks on how to increase the success of large scale implementation were combined into a Consolidated Framework for Implementation.

Here are a few major reasons that scaling up of successful pilots may fail:

  1. The pilot did not actually work (look at the actual data, not the hype).
  2. The people studied in the pilot are not representative of the general population.
  3. Efforts to scale up implementations cut corners and no longer follow key aspects of the pilot program.
  4. Scaling up does not account for limited supply of qualified staff and other inputs.
  5. Scaling up assumes the “build it and they will come” theory; that demand for the intervention will spontaneously be high. An insufficient marketing plan is included.

Over the course of our careers, as we experience or witness failed implementations, it is too easy to develop a sense of fatalism about many proposed expansions. In the case of mass COVID vaccination, our society, health care delivery system, and economy, demand that we have a different mindset. Successful implementation is hard, it is a skill-set, but it importantly reflects a “can do” mindset, not a “can’t do” mindset. It means tackling challenges head on, seeking new solutions to problems encountered, including the key challenge of vaccine hesitancy.

We at PHC thank you, and your staff, for your work on promoting COVID vaccination among your staff and in your community, in the weeks ahead.

More Infectious COVID Strain Will Require Higher Vaccination Rates

By Robert L. Moore, MD, MPH, MBA, Chief Medical Officer

“One of the biggest myths in medicine is the idea that all we need are more medical breakthroughs and then all our problems will be solved.”

-Dr. Quyen Nguyen, Pioneer in Fluorescence-Guided Surgery

Most recent estimates from Great Britain are that the SARS-CoV2 VOC 202012/1, also known as COVID-19 variant (B.1.1.7) is 50% more infectious than the previously dominant COVID strain. DNA sequencing of samples of SARS-CoV2 has been at very low rates in the United States, so we don’t know how quickly this strain is spreading. On Wednesday, San Diego County announced that they had detected 34 cases in the previous few days.

Fortunately, this strain is no more deadly or likely to cause serious illness than other COVID strains. It appears to be more infectious due to a higher number of particles being shed in the early pre-symptomatic or asymptomatic phase.

Unfortunately, a higher rate of infectiousness means that we will need higher rates of vaccination to achieve herd immunity and stop the spread of COVID. Some estimate that a vaccination rate of 90% will be needed to achieve herd immunity to this new strain, instead of the 70% we were counting on since March 2020. In addition, the current distance and time standards (6 feet and 15 minutes) that define high risk exposures may need to be changed as this more infectious strain spreads.

Even when we get past the current major logistical challenges involved in vaccine prioritization and distribution, given high rates of vaccine hesitancy, we have a major public health challenge ahead, which will require consistent strong communication from you, your clinicians and your staff.

By all accounts, much of 2021 is shaping up to look like 2020, from a COVID perspective.

The January 6 edition of the New England Journal of Medicine included a comprehensive overview of the many strategies that can be used to increase vaccination rates. Here is their list of recommendations for primary care clinicians:

  1. Prepare a list of common vaccine questions
  2. Investigate specific concerns of your various segments of patients
  3. Develop a list of effective responses
  4. Practice and train staff for responses
  5. Add incentives (free sports exams, prizes).
  6. Develop prompts to persuade vaccine-hesitant patients and offer compromises.
  7. Make vaccination status observable in your community

In addition, they describe how to vary the message, depending on the level of vaccine hesitancy.

The article describes the targeted strategies in more detail.

For the good of our communities, our health, and our economy, thank you for training and mobilizing your staff to rise to this public health challenge!