COVID-19

SARS-CoV-2 (COVID-19) Update

It’s time for our next 14-day moving average determinations and projections for infections and deaths from SARS-CoV-2 for the United States and my thoughts on vaccines and mutant viruses. We use the WORLDOMETERS aggregators data set to make our projections of future total infections and deaths since it includes data from the Department of Veterans Affairs, the U.S. Military, federal prisons and the Navajo Nation.

In the United States, SARS-CoV-2 deaths have decreased for the second time in a 14-day period. There were 843 fewer deaths per day than in the last 14-day period. In the last 14 days, the number of infections has decreased by 39,769 infections per day. This decrease in infections over the last three 14-day periods may represent increased mask usage and social distancing, which are a part of the Biden 100-day SARS-CoV-2 plan (day 38 of plan). On 2/26/21, 81,942 new infections occurred in the United States. There were also 2,280 deaths. The number of hospitalized patients is decreasing, and only 15,478 patients are critically ill. The number of critically ill patients has decreased by 4,449 in the last 14 days, while 28,426 new deaths occurred. This suggests that the number of critically ill patients is decreasing because a large number of patients are dying. 

As of 2/16/21, we have had 523,116 deaths and 29,138,228 SARS-CoV-2 infections in the United States. We have had 990,465 new infections in the last 14 days. We are adding 495,232 infections every 7 days. Each million infections usually results in at least 20,000 deaths. On 2/26/21, nineteen states have had greater than 500,000 total infections, and 29 states had greater than 5,000 total deaths. 

On 11/20/20 in the United States, 3.70% of the population had a documented SARS-CoV-2 infection. California was ranked 41st in infection percentage at 2.77%. In North Dakota 9.18% of the population was infected (ranked #1), and in South Dakota 8.03% of the population was infected (ranked #2).

As of 2/26/21, in the United States 8.76% of the population has had a documented SARS-CoV-2 infection. In the last 3 months 5% of our country became infected with SARS-CoV-2. 

As of 2/26/21, California was ranked 26th in infection percentage at 8.74%. In North Dakota 13.08% of the population was infected (ranked #1) and in South Dakota 12.67% of the population was infected (ranked #2). Twenty-five states have greater than 9% of their population infected and 44 states have greater than 6% infected. Only four states have less than 4% of their population infected: Oregon (3.67%), Maine (3.29%), Vermont (2.39%), and Hawaii (1.93%). 

New Mutants

A new mutant SARS-CoV-2 virus (lineage B.1.1.7), first seen in the UK in September, has now been found in multiple other countries. There are 2,102 reported cases in the US as of 2/26/21. This isolate has now been found in 44 states and the District of Columbia. This isolate (let’s call it Lineage B.1.1.7 or SARS-CoV-2 UK) is more infectious than other previously circulating B2 lineage isolates. There are two deletions and six other mutations in its spike protein. One mutation involves a change of one amino acid, an asparagine at position 501 in the receptor binding motif with a tyrosine. This enhances binding (affinity) to the ACE-2 receptor and may alone be responsible for the increased infectivity of this isolate. Due to air and other travel, this isolate will become the dominant isolate worldwide. 

B.1.351, also known as the South African isolate, has 49 reported cases and has occurred in 15 states and the District of Columbia. The P.1 isolate (Brazil) has 16 reported cases and has been found in five states. (This data is available at https://www.cdc.gov/coronavirus/2019-ncov/transmission/variant-cases.html.)

A new, disturbing report out of the UK has found a second mutation in B.1.1.7. This mutation, which occurs in the loop sequence has also been found in the South African (B.1.351) and Brazilian (P.1) variants. (The loop sequence is in the receptor binding motif in the receptor binding domain of the S1 sequence of the spike protein.) This mutation involves a change of one amino acid of the spike protein, number 484, from glutamic acid to lysine. This point mutation allows the virus to bind better to the ACE2 receptor, which increases infectivity. People who are exposed to one of these variants (verus the old B2 isolate) are more likely to be infected and are more likely to transmit the virus to others. 

In our last two updates we summarized a research letter published in Clinical Infectious Diseases about a patient in the UK who was first infected in April with a B2 isolate and experienced only mild symptoms but was infected with the new B.1.1.7 variant in December and became critically ill. The patient described in this research letter was not protected by a natural infection with a B2 lineage SARS-CoV-2 isolate in April 2020 from having a potentially lethal second infection with a B.1.1.7 lineage variant in December 2020, suggesting that folks who have had a past SARS-CoV-2 infection should not expect to have any immunity to new variants such as B.1.1.7. All of the currently available vaccines were developed with spike protein from B2 lineages. Moderna, Pfizer, and AstraZeneca/Oxford are currently remaking their spike protein vaccines to address the mutations in the South African variant of SARS-CoV-2 because the AstraZeneca/Oxford vaccine did not work in a small trial in South Africa, where most of the patients had the South African mutant (B.1.351). 

A California Mutant

A fourth mutant isolate (CAL.20C) of SARS-CoV-2 has been identified in California. This isolate does not have any of the mutations mentioned above, but contains five mutations, three of which are in the spike protein, but not in the receptor binding motif. This mutant may be partially responsible for the massive increase in infections in California, to include infections of people who had already recovered from a SARS-CoV-2 infection earlier. In California to date, we have had 3,547,280 infections and 51,377 total deaths. California is averaging 357 deaths per day in the last 14 days. Currently, 8.76% of the population in California is infected. Nationally, we rank 26th in the percentage of people in the state infected. To my knowledge, only one privately held company is currently modifying their vaccine to cover the CAL.20C (California) mutant. 

Watching the Data

Over the next few months, we’ll be paying close attention to correlations between the SARS-CoV-2 data, the number of isolates identified in various countries and states, and the non-pharmaceutical interventions (like mask mandates and lockdowns) put in place by state and national governments.

The Road Ahead

We are just on Day 38 of the Biden-Harris administration.The President has made the pandemic a first priority and has now ordered enough vaccine to vaccinate everyone who wants a vaccination by July 2021. Testing, wearing masks, social distancing and washing our hands frequently should no longer be political issues. These are non-pharmaceutical interventions used by most successful countries and some states to protect their citizens and their economies. New Zealand, Taiwan, and Australia are three countries that have done this successfully.  In the United States, Vermont and Hawaii are doing a better job handling the pandemic than many of our states. These interventions with vaccination should keep the pandemic from overwhelming our health care delivery system. New mutations will probably increase the numbers of infections occurring in the United States over the next 30 days. At least one mutant from the UK, B.1.1.7, has increased the number of infections, hospitalizations and deaths. This mutant may do the same thing in the USA.

The Pfizer and Moderna RNA vaccines are approved in the USA and the Johnson & Johnson single dose vaccination should be approved this weekend. The Oxford-AstraZeneca vaccine and Novavax vaccine should also be available in the second quarter of 2021. To vaccinate 80% of our population with two doses of a vaccine, we will need over 500 million doses of vaccine. The current goal of the Biden administration in the US is to vaccinate one million people each day for 100 days. The good news is that we are averaging 1.5 million vaccinations a day and have opened mass vaccination sites in multiple cities and states. 

The bad news is that all currently available vaccines are based on the Chinese spike protein sequence from December 2019. Mutated isolates, as discussed above, may overtake our ability to produce new vaccines and vaccinate the populace. Like Influenza vaccines, we may have to reformulate vaccines based on active, worldwide surveillance at least every 4 to 6 months. The FDA is currently putting together a guidance document for how to develop booster vaccines for SARS-CoV-2 mutations. A surrogate marker of protection like antibody to the mutated Receptor Binding Domains of SARS-CoV-2 should be considered for vaccine approval. 

We still need to perform more virus isolations and perform more DNA sequencing of viruses in each country, state, populous city, and county if we are to rapidly identify new mutations. I’m more hopeful that we will have the facilities, the equipment, and the trained staff needed to perform this work. As a nation we are finally preparing to make more vaccine, new vaccines directed against mutants, and the necessary rapid tests and protective equipment needed by medical staff, first responders, essential workers and especially teachers and students. I’m still hopeful we can work together on our and the world’s infectious disease problems. 

COVID-19

Updated Modeling for COVID-19

On October 1, we predict there will be 3,887,718 COVID-19 infected patients in the United States. Our estimate, based on 3,887,718 infections on October 1 (inclusive) would be that we will have 170,492 deaths. Depending on whether the death rate changes, we could have upwards of 205,266 deaths, but we feel confident, based on our modeling, that the number of deaths will be closer to 170,492. We will be reassessing these numbers every 7 days.

For daily COVID-19 updates, follow Dr. Wright on Twitter!