In the spirit of reading as many facts as possible to build a point of view, I submit this vast research on corona virus from my amazing and brilliant physician. As a scientist, she is completely unbiased in her presentation of these facts. Over time, we will discover which approach(es)worked best. It may be fortuitous that different countries approached this crisis differently, so we will have a basis for evaluating this kind of challenge in the future. Is Sweden’s laissez-faire attitude going to prove the most prescient, or is it the draconian approach of locking down everyone until there are zero deaths? Or maybe the best model is somewhere in the middle? Two-week shutdown and back to work? Only lock down those “at risk?” Which is better for humanity short term? Which is better long term? Lots of questions exist out there. Are we working together to save humanity or are we just losing our freedom? Do the masks actually work or does the virus go right through as some scientists claim and Government is overreaching by forcing their use? Who to save? Young futures or old lives?Are we getting closer to our loved ones or are we sacrificing the educations of our youth? How about herd immunity. Do we lose it for future generations if we isolate now? What are the long term effects of what the financial world is calling The Great Suppression? Will this be a deep V or a long L? Should we be the huddled masses or should we get back to work? I hope you enjoy the various perspectives presented. And please… think for yourself. Don’t immediately delegate your opinions and give your brain up to the local news or to the political leaders. Analyze the data. Read on. Best, Tim
Hello —
We have now had over a month of “shelter in place” to combat the spread of COVID-19 and to avoid a surge in hospital admissions that would overwhelm our healthcare system. In California, we have been successful at flattening the curve and our numbers of hospitalizations and deaths have been far below those initially projected. The original Imperial College projection for the 6 county Bay area was 44,484 deaths. We have had approximately 170 deaths. However, we continue to see new cases of Covid19 and the death toll continues to rise. Realistically this will be the case for the foreseeable future until we develop herd immunity either through pervasive disease or a vaccine (see below). As the economic, social, and political costs of continued “shelter in place” rise, we see more discussion regarding when and how to lift restrictions… We are asking how to best live with this virus — What can we do to stay as safe as possible and minimize the risks to others? How will we be able to work and stay connected with the people we love with transmission risks of Covid19?
With these questions in mind, I would like to update you on what we have learned that can help us, recognizing that new information emerges daily.
We have still have no proven treatments for Covid19. The only tools we have to stop the spread of this disease are social distancing and hygiene measures — washing hands and surfaces, keeping hands away from the face and wearing a mask to limit dispersion of the respiratory droplets that are naturally formed as we breath. These droplets carry the COVID-19 causing virus — SARS Co-V2. When a person breaths viral laden droplets into the mouth or nose or the virus enters the eyes, that person can become infected.
How is Covid 19 transmitted?
Covid 19 spreads through close contact with others — primarily through breathing virus in air droplets but aerosolized smaller particles containing virus can also be infectious particularly in enclosed spaces, like churches, meeting rooms, subway cars and restaurants. Transmission also occurs through touching shared surfaces that have been contaminated with virus and then touching your eyes, nose or mouth.
What are the symptoms?
The symptoms of Covid19 include fevers, muscle aches, headaches, sore throat, fatigue, runny or stuffy nose, conjunctivitis, cough and losing sense of smell. Patients may have nausea, vomiting and diarrhea. More recently “Covid toes” has been described. These are red or blue lesions on the feet (and occasionally the hands) that can be painful to the touch and produce hot burning sensations. The lesions typically resolve on their own in 7–10 days and may be the only symptom. Covid toes may be the result of tiny clots or inflammation in the blood vessels but no one yet knows for sure.
More severely ill patients may have cardiac injury, including heart attacks, liver inflammation, kidney injury, pneumonia, and clotting complications. Some present with neurological symptoms including seizures and strokes.
Some people who are infected with the virus have NO symptoms. We do not know the exact number of people in this category. But we are starting to get more data…
In a screening study of 215 obstetrical patients who presented in NYC to give birth, among 211 asymptomatic women, 29 tested positive for SARS-CoV2. Four symptomatic women also tested positive…Thus, 29 out of the 33 or 88% of infected patients had no symptoms.
In the Covid19 outbreak on the Theodore Roosevelt naval ship, the Navy tested most of the 4,800+ member crew. Ultimately 840 sailors tested positive, but among the 678 initially tested and positive, roughly 60 percent had no symptoms at the time.
In a population study done in Iceland, 43% of those who tested positive for Covid19 reported no symptoms at the time of testing. This is in contrast to 29% of those who tested negative and reported symptoms of Covid19. Covid19 symptoms are common and not always Covid19. https://www.nejm.org/doi/full/10.1056/NEJMoa2006100
It is likely that the majority of Covid19 infections have no symptoms and/or only mild to moderate symptoms not requiring hospitalization. There are also pre-symptomatic infections where after a week or so of asymptomatic viral shedding, symptoms appear. This characteristic, the ability of SARS CoV2 to infect hosts who do not appear or feel ill, who do not have fevers, yet breath virus into the air to infect other people, presents one of the biggest challenges in trying to stop viral transmission.
What about hospitalized patients? Who gets hospitalized and has more severe disease?
We do not know the exact percentage of people who become infected with SARS-CoV2 who will require hospitalization, but we are learning more about them…The estimates are around 20 percent of all patients, but the risk is overwhelmingly among older patients who have underlying medical conditions.
The CDC reported that in the month of March, the age distribution for hospitalizations was as demonstrated in the graph below:
The characteristics of 5700 patients hospitalized in New York City hospitals between March 1st and April 4th were recently reported. Among these patients the most common comorbidities were hypertension 57%, obesity 42% and diabetes 34%. In this case series 2634 were discharged or died during the study time period. Among these patients, 14% were treated in the ICU, 12% received mechanical ventilation, and 21% died. Overall 31% of patients presented with fever, 17% were breathing rapidly and 28% were receiving supplemental oxygen. Mortality was zero for males and female patients younger than 20 years old (20 patients). Mortality rates for males were higher than females for every 10-year age interval older than 20 years. Mortality rates for those less than 65 on a ventilator were 76% vs. 97% for those older than 65 with overall mortality for those on ventilators of 88%. Mortality rates for those 18–65 who were not on a ventilator were 20% vs. 27% for older than 65. Patients who were less than 50, who were discharged or died during the study period and had no comorbidities made up 17% of admitted patients (436 patients). Nine died.
Patients with diabetes were more likely to require mechanical ventilation or care in the ICU compared with those who did not have diabetes. They were also more likely to experience kidney injury.
Although most patients who contract Covid19 do very well without treatment, for the not insignificant minority who are hospitalized, the disease can be severe and deadly….The number of young, previously healthy people who die is low but not zero.
California hospitalizations have been much lower in number than New York. We currently have 3,357 in the hospital with 1219 in the ICU..
How many people have been infected?
We do not know for sure. Reported confirmed cases reflects availability of testing and testing has been limited by shortages. In California, we have close to 38,000 confirmed cases and over 1400 deaths. The only way to know who is infected and who has been infected is to have an accurate test. We have started to gather data from antibody studies that will help us answer the question of how many have actually been infected. (see below).
Who is getting infected?
While we are all at risk of infection, those in confined spaces are more at risk…Cruise ships, jails and prisons, homeless shelters and nursing homes have all reported large outbreaks.
What about testing?
There are two types of tests for Covid19 — those based on finding the RNA of the virus that causes Covid19 in nasopharyngeal secretions and those based on antibodies in the blood manufactured by immune system cells after infection.
The best diagnostic Covid test is a reverse transcriptase PCR test that detects the RNA of the virus in respiratory secretions collected with a nasopharyngeal swab from the back of the throat. Currently, Stanford has one of the first FDA approved tests with sensitivity of 96% (yielding a positive test 96% of the time if you have the virus using repeat testing within 48 hours as the gold standard). The clinical specificity (correctly identifying true negative results) approaches 100 percent.
There have been reported problems with the accuracy of some tests. False negative results as high as 30% have been reported at other institutions. A false negative rate of 15% has now been reported with the quick point of service test from Abbott. This may be due to issues around viral specimen transport media and has yet to be worked out.
There has been recent FDA approval of a self-administered test by Labcorp which should become available in a few weeks. There has also been a test developed that looks for the virus in saliva.
Serological antibody tests on blood allow us to detect and measure the antibodies manufactured by immune system cells after Covid19 infection. Stanford also has one of the first FDA approved antibody tests. It is an ELISA test (enzyme-linked immunosorbent assay). Other antibody tests use a lateral flow immunoassay. It takes time for the body to manufacture antibodies after the onset of infection.
In patients at Stanford,during the first week following a positive PCR test, only 25% had antibodies; between the 1st and 2nd weeks, 65% had antibodies. The test sensitivity to date is 100% at 3 weeks when done on serum of patients with positive PCRs. This type of test is less useful for diagnosis and more useful for understanding the patterns of the disease in populations, determining who has had the virus in the past and determining the possibility of immunity and efficacy of vaccines. On 120 samples initially tested, there were no false positives — there has since been possibly one.
We do not yet know if antibodies provide immunity and if so for how long. We do not know if those with antibodies can still transmit Covid19. We believe there may be those who have had Covid19 who do not make antibodies. There is active research in these areas.
What have we learned about the prevalence of COVID19 from antibody tests?
Several reported studies — with various methods and populations have given us information about what percentage of people actually have had Covid19 in our populations.
Although we initially thought the first Covid19 death was in California was in March, an autopsy report released yesterday revealed that a 57 year old woman in Santa Clara died of Covid19 on February 6. This suggests transmission in our area started much earlier than previously thought — probably early January.
A study done in Santa Clara county April 3rd and 4th measured the prevalence of antibodies to SARS-CoV2 among 3,330 people recruited through Facebook ads. 1.5% of those tested had antibodies to the virus. Using statistical methods, the researchers adjusted the results for zip code, sex, race and ethnicity and estimated that between 2.5% and 4.2% of the population was infected. This translates to between 48,000 and 81,000 infected people by early April. This is between 50 and 85 times the number of confirmed cases and has implications for case fatality estimates and epidemiological projections. The study results have been questioned because of the statistical assumptions and the over-representation of middle-aged white women working at home without a travel history represented in the tested sample. That said, we have many more infected people in Santa Clara county than the confirmed numbers suggest. https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v1
Recently physicians at Massachusetts General Hospital tested blood from 200 people in Chelsea, a suburb north of Boston. Previously tested people were excluded. Approximately 1/3 of those tested (64 people) had Covid antibodies. Extrapolating this to the population, 30 percent of people in the area may have been infected. https://www.dailymail.co.uk/news/article-8232857/One-people-Massachusetts-study-tested-positive-COVID-19-antibodies.html
A study testing for antibodies in the blood of all 8000 or so residents of Telluride, Colorado is in process. Preliminary results from 986 samples showed 8 positives and 23 indeterminate suggesting a prevalence of 0.8 percent if only the positives are counted and 3 percent if the indeterminate results (possibly representing early infection) are included. Extrapolating these results to the nation at large, the researchers estimate between 2.6 million and 10 million infections in the US…The Johns Hopkins Dashboard currently reports 856,209 confirmed cases in the US.
April 20, the LA times reported preliminary results of a USC study testing 863 adults selected through a market research firm to represent the makeup of LA county. They found that 4.1% of adults had antibodies to the virus. Correcting for margin of error, they estimate the results reflect between 221,000 to 442,000 Covid19 infections in LA county (2.8 to 5.6% of adults infected). At the time, LA county reported fewer than 8,000 confirmed cases. The LA study results have also been called into question because the antibody test used has not been FDA approved, although this is allowed for public health surveillance. This is also true of the antibody test used for the Stanford study (a laminar flow immunoassay). The USC study methods have not yet undergone peer review. https://www.latimes.com/california/story/2020-04-20/coronavirus-serology-testing-la-county
The results of the USC LA study and the Santa Clara county study done by Stanford researchers suggest that the mortality rate for Covid19 is 0.1% to 0.2%, closer to the death rate associated with the seasonal flu.
Hot off the press…Andrew Cuomo tweeted today that a statewide antibody study collecting approximately 3,000 antibody samples from 50 locations in 19 New York counties, found 13.9 % of those participating had antibody evidence of infection.
What about herd immunity and a vaccine?
To achieve herd immunity, approximately 70% of the population must have antibodies that provide protection from the disease. As you can see from the data above, we are nowhere even close. To reach herd immunity in the population in the absence of a vaccine, we would have to accept high mortality numbers. Historically, the fastest time frame for developing a vaccine for a novel virus was 4 years for the mumps vaccine in the 50s and more recently 5 years for the Ebola vaccine. Finding a vaccine for Covid19 poses specific challenges that scientists have not yet had to confront according to Ian Frazer, an Australian vaccine expert involved in creating the HPV vaccine. It has been difficult to make safe coronavirus vaccines, he reports, because of the unique way coronaviruses interact with the immune system. He says that one of the problems with coronavirus vaccines in the past has been that in animal models, after immunization, when the immune response targets the cells infected with virus, inflammation in the lungs was increased, creating more pathology rather than less. https://www.abc.net.au/news/health/2020-04-17/coronavirus-vaccine-ian-frazer/12146616
Researchers around the world are working hard to find a successful vaccines but we must be careful to be sure we have a safe and effective vaccine before moving to vaccinate around the world. That unfortunately is likely to be at least 2 or more years away, not months.
What about treatments?
There are currently NO proven effective treatments, but many drugs are being studied in the United States and throughout the world. Some highlights:
— Early reports of hydroxychloroquine and azithromycin in severely ill patients suggest no effect and possibly increased mortality due to cardiac toxicities. Some places have stopped using it and it is not recommended outside of ongoing clinical trials.
— Remdesivir early reports suggest some efficacy in severely ill patients. We await results of clinical trials using it in moderately ill hospitalized patients. These should be released in early May. Anecdotal reports have been promising. We expect remdesivir would be most effective early in the course of the disease as a therapy that interrupts viral replication. It is given IV.
— Convalescent plasma appears promising and ongoing studies are underway.
— Various neutralizing antibodies and immune system modulators are being studied for use later in the course of the disease when it appears that immune system dysfunction (cytokine storm) rather than viral replication plays a role in the course and severity of the disease.
What are the next step towards safely lifting restrictions?
The California governor has outlined a framework for reopening the economy and easing restrictions. He has said dates would be determined by our ability to do six things:
1. The ability to monitor and protect our communities through testing, contact tracing, isolating, and supporting those who are positive or exposed.
It is estimated we need to be able to test 60–80 thousand people daily. We are currently testing around 16,000 per day due to limited testing supplies. Efforts to expand testing capacity are underway. Public health workers are being hired to perform the tasks of case finding and contact tracing to try to limit spread of Covid19 as we lift restrictions. In San Francisco, librarians are being hired to do this work and trained by public health professionals. Apps are being developed by Google and Apple to support contract tracing but privacy concerns have been raised.
2. The ability to prevent infection in people who are at risk for more severe COVID-19 — primarily the elderly and those with underlying conditions
3. The ability of the hospital and health systems to handle surges with adequate PPE.
Given that hospitals in California currently have adequate capacity, elective surgeries will resume. Stanford is starting the week of May 4.
4. The ability to develop therapeutics to meet the demand — We are not there.
5. The ability for businesses, schools, and child care facilities to support physical distancing
6. The ability to determine when to reinstitute certain measures, such as the stay-at-home orders, if necessary.
Some experts, recognizing the severe human costs of prolonged economic shutdown have proposed strategies for lifting restrictions even if we fail to achieve testing goals, effective anti-viral treatments and a vaccine. This paper, from a public policy think tank in Austin is co-authored by the Chairman of the Department of Medicine at UCSF, Bob Wachter, MD. and is an excellent discussion integrating medical facts with the economic realities. https://freopp.org/a-new-strategy-for-bringing-people-back-to-work-during-covid-19-a912247f1ab5
Other states and countries like Sweden have taken a different approach. Here is a link to information about the Swedish method…https://www.livemint.com/news/world/sweden-says-its-no-lockdown-strategy-proving-effective-against-coronavirus-11587365383534.html
How can we protect ourselves and others?
The answer is we can’t perfectly… As we lift restrictions we are likely to see an increase in Covid19 infections. Each of us has a different tolerance for risk and willingness to restrict our activities and social connections with family and friends. It is my hope that the information provided here and available from many reliable sources will guide your choices as you assess your own personal risk and that of those around you.
How we do this will have huge ramifications for our community and our future.
Please contact me if you have any questions or I can be of help.
Take care, Kathy
On a lighter note:
Here is a link to an article providing practical suggestions for optimal mental health during the Covid epidemic from local psychiatrist and former University of Pennsylvania All-American captain of the fencing team, Danielle Kamis, MD. https://www.kamismd.com/post/finding-structure-in-chaos
Check out this ring — Oura — that tracks your sleep, breathing, activity and temperature. The company that makes this device has partnered with UCSF in a research study to see if by tracking this data and using artificial intelligence, they can predict and alert those who may have contracted SARS CoV 2, the virus causing Covid19…I have one and love it! https://ouraring.com/
For a thought-provoking and inspiring essay, check out Marc Andreessen’s piece reflecting on lessons of Covid19 https://a16z.com/2020/04/18/its-time-to-build/
Hello —
We have now had over a month of “shelter in place” to combat the spread of COVID-19 and to avoid a surge in hospital admissions that would overwhelm our healthcare system. In California, we have been successful at flattening the curve and our numbers of hospitalizations and deaths have been far below those initially projected. The original Imperial College projection for the 6 county Bay area was 44,484 deaths. We have had approximately 170 deaths. However, we continue to see new cases of Covid19 and the death toll continues to rise. Realistically this will be the case for the foreseeable future until we develop herd immunity either through pervasive disease or a vaccine (see below). As the economic, social, and political costs of continued “shelter in place” rise, we see more discussion regarding when and how to lift restrictions… We are asking how to best live with this virus — What can we do to stay as safe as possible and minimize the risks to others? How will we be able to work and stay connected with the people we love with transmission risks of Covid19?
With these questions in mind, I would like to update you on what we have learned that can help us, recognizing that new information emerges daily.
We have still have no proven treatments for Covid19. The only tools we have to stop the spread of this disease are social distancing and hygiene measures — washing hands and surfaces, keeping hands away from the face and wearing a mask to limit dispersion of the respiratory droplets that are naturally formed as we breath. These droplets carry the COVID-19 causing virus — SARS Co-V2. When a person breaths viral laden droplets into the mouth or nose or the virus enters the eyes, that person can become infected.
How is Covid 19 transmitted?
Covid 19 spreads through close contact with others — primarily through breathing virus in air droplets but aerosolized smaller particles containing virus can also be infectious particularly in enclosed spaces, like churches, meeting rooms, subway cars and restaurants. Transmission also occurs through touching shared surfaces that have been contaminated with virus and then touching your eyes, nose or mouth.
What are the symptoms?
The symptoms of Covid19 include fevers, muscle aches, headaches, sore throat, fatigue, runny or stuffy nose, conjunctivitis, cough and losing sense of smell. Patients may have nausea, vomiting and diarrhea. More recently “Covid toes” has been described. These are red or blue lesions on the feet (and occasionally the hands) that can be painful to the touch and produce hot burning sensations. The lesions typically resolve on their own in 7–10 days and may be the only symptom. Covid toes may be the result of tiny clots or inflammation in the blood vessels but no one yet knows for sure.
More severely ill patients may have cardiac injury, including heart attacks, liver inflammation, kidney injury, pneumonia, and clotting complications. Some present with neurological symptoms including seizures and strokes.
Some people who are infected with the virus have NO symptoms. We do not know the exact number of people in this category. But we are starting to get more data…
In a screening study of 215 obstetrical patients who presented in NYC to give birth, among 211 asymptomatic women, 29 tested positive for SARS-CoV2. Four symptomatic women also tested positive…Thus, 29 out of the 33 or 88% of infected patients had no symptoms.
In the Covid19 outbreak on the Theodore Roosevelt naval ship, the Navy tested most of the 4,800+ member crew. Ultimately 840 sailors tested positive, but among the 678 initially tested and positive, roughly 60 percent had no symptoms at the time.
In a population study done in Iceland, 43% of those who tested positive for Covid19 reported no symptoms at the time of testing. This is in contrast to 29% of those who tested negative and reported symptoms of Covid19. Covid19 symptoms are common and not always Covid19. https://www.nejm.org/doi/full/10.1056/NEJMoa2006100
It is likely that the majority of Covid19 infections have no symptoms and/or only mild to moderate symptoms not requiring hospitalization. There are also pre-symptomatic infections where after a week or so of asymptomatic viral shedding, symptoms appear. This characteristic, the ability of SARS CoV2 to infect hosts who do not appear or feel ill, who do not have fevers, yet breath virus into the air to infect other people, presents one of the biggest challenges in trying to stop viral transmission.
What about hospitalized patients? Who gets hospitalized and has more severe disease?
We do not know the exact percentage of people who become infected with SARS-CoV2 who will require hospitalization, but we are learning more about them…The estimates are around 20 percent of all patients, but the risk is overwhelmingly among older patients who have underlying medical conditions.
The CDC reported that in the month of March, the age distribution for hospitalizations was as demonstrated in the graph below:
The characteristics of 5700 patients hospitalized in New York City hospitals between March 1st and April 4th were recently reported. Among these patients the most common comorbidities were hypertension 57%, obesity 42% and diabetes 34%. In this case series 2634 were discharged or died during the study time period. Among these patients, 14% were treated in the ICU, 12% received mechanical ventilation, and 21% died. Overall 31% of patients presented with fever, 17% were breathing rapidly and 28% were receiving supplemental oxygen. Mortality was zero for males and female patients younger than 20 years old (20 patients). Mortality rates for males were higher than females for every 10-year age interval older than 20 years. Mortality rates for those less than 65 on a ventilator were 76% vs. 97% for those older than 65 with overall mortality for those on ventilators of 88%. Mortality rates for those 18–65 who were not on a ventilator were 20% vs. 27% for older than 65. Patients who were less than 50, who were discharged or died during the study period and had no comorbidities made up 17% of admitted patients (436 patients). Nine died.
Patients with diabetes were more likely to require mechanical ventilation or care in the ICU compared with those who did not have diabetes. They were also more likely to experience kidney injury.
Although most patients who contract Covid19 do very well without treatment, for the not insignificant minority who are hospitalized, the disease can be severe and deadly….The number of young, previously healthy people who die is low but not zero.
California hospitalizations have been much lower in number than New York. We currently have 3,357 in the hospital with 1219 in the ICU..
How many people have been infected?
We do not know for sure. Reported confirmed cases reflects availability of testing and testing has been limited by shortages. In California, we have close to 38,000 confirmed cases and over 1400 deaths. The only way to know who is infected and who has been infected is to have an accurate test. We have started to gather data from antibody studies that will help us answer the question of how many have actually been infected. (see below).
Who is getting infected?
While we are all at risk of infection, those in confined spaces are more at risk…Cruise ships, jails and prisons, homeless shelters and nursing homes have all reported large outbreaks.
What about testing?
There are two types of tests for Covid19 — those based on finding the RNA of the virus that causes Covid19 in nasopharyngeal secretions and those based on antibodies in the blood manufactured by immune system cells after infection.
The best diagnostic Covid test is a reverse transcriptase PCR test that detects the RNA of the virus in respiratory secretions collected with a nasopharyngeal swab from the back of the throat. Currently, Stanford has one of the first FDA approved tests with sensitivity of 96% (yielding a positive test 96% of the time if you have the virus using repeat testing within 48 hours as the gold standard). The clinical specificity (correctly identifying true negative results) approaches 100 percent.
There have been reported problems with the accuracy of some tests. False negative results as high as 30% have been reported at other institutions. A false negative rate of 15% has now been reported with the quick point of service test from Abbott. This may be due to issues around viral specimen transport media and has yet to be worked out.
There has been recent FDA approval of a self-administered test by Labcorp which should become available in a few weeks. There has also been a test developed that looks for the virus in saliva.
Serological antibody tests on blood allow us to detect and measure the antibodies manufactured by immune system cells after Covid19 infection. Stanford also has one of the first FDA approved antibody tests. It is an ELISA test (enzyme-linked immunosorbent assay). Other antibody tests use a lateral flow immunoassay. It takes time for the body to manufacture antibodies after the onset of infection.
In patients at Stanford,during the first week following a positive PCR test, only 25% had antibodies; between the 1st and 2nd weeks, 65% had antibodies. The test sensitivity to date is 100% at 3 weeks when done on serum of patients with positive PCRs. This type of test is less useful for diagnosis and more useful for understanding the patterns of the disease in populations, determining who has had the virus in the past and determining the possibility of immunity and efficacy of vaccines. On 120 samples initially tested, there were no false positives — there has since been possibly one.
We do not yet know if antibodies provide immunity and if so for how long. We do not know if those with antibodies can still transmit Covid19. We believe there may be those who have had Covid19 who do not make antibodies. There is active research in these areas.
What have we learned about the prevalence of COVID19 from antibody tests?
Several reported studies — with various methods and populations have given us information about what percentage of people actually have had Covid19 in our populations.
Although we initially thought the first Covid19 death was in California was in March, an autopsy report released yesterday revealed that a 57 year old woman in Santa Clara died of Covid19 on February 6. This suggests transmission in our area started much earlier than previously thought — probably early January.
A study done in Santa Clara county April 3rd and 4th measured the prevalence of antibodies to SARS-CoV2 among 3,330 people recruited through Facebook ads. 1.5% of those tested had antibodies to the virus. Using statistical methods, the researchers adjusted the results for zip code, sex, race and ethnicity and estimated that between 2.5% and 4.2% of the population was infected. This translates to between 48,000 and 81,000 infected people by early April. This is between 50 and 85 times the number of confirmed cases and has implications for case fatality estimates and epidemiological projections. The study results have been questioned because of the statistical assumptions and the over-representation of middle-aged white women working at home without a travel history represented in the tested sample. That said, we have many more infected people in Santa Clara county than the confirmed numbers suggest. https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v1
Recently physicians at Massachusetts General Hospital tested blood from 200 people in Chelsea, a suburb north of Boston. Previously tested people were excluded. Approximately 1/3 of those tested (64 people) had Covid antibodies. Extrapolating this to the population, 30 percent of people in the area may have been infected. https://www.dailymail.co.uk/news/article-8232857/One-people-Massachusetts-study-tested-positive-COVID-19-antibodies.html
A study testing for antibodies in the blood of all 8000 or so residents of Telluride, Colorado is in process. Preliminary results from 986 samples showed 8 positives and 23 indeterminate suggesting a prevalence of 0.8 percent if only the positives are counted and 3 percent if the indeterminate results (possibly representing early infection) are included. Extrapolating these results to the nation at large, the researchers estimate between 2.6 million and 10 million infections in the US…The Johns Hopkins Dashboard currently reports 856,209 confirmed cases in the US.
April 20, the LA times reported preliminary results of a USC study testing 863 adults selected through a market research firm to represent the makeup of LA county. They found that 4.1% of adults had antibodies to the virus. Correcting for margin of error, they estimate the results reflect between 221,000 to 442,000 Covid19 infections in LA county (2.8 to 5.6% of adults infected). At the time, LA county reported fewer than 8,000 confirmed cases. The LA study results have also been called into question because the antibody test used has not been FDA approved, although this is allowed for public health surveillance. This is also true of the antibody test used for the Stanford study (a laminar flow immunoassay). The USC study methods have not yet undergone peer review. https://www.latimes.com/california/story/2020-04-20/coronavirus-serology-testing-la-county
The results of the USC LA study and the Santa Clara county study done by Stanford researchers suggest that the mortality rate for Covid19 is 0.1% to 0.2%, closer to the death rate associated with the seasonal flu.
Hot off the press…Andrew Cuomo tweeted today that a statewide antibody study collecting approximately 3,000 antibody samples from 50 locations in 19 New York counties, found 13.9 % of those participating had antibody evidence of infection.
What about herd immunity and a vaccine?
To achieve herd immunity, approximately 70% of the population must have antibodies that provide protection from the disease. As you can see from the data above, we are nowhere even close. To reach herd immunity in the population in the absence of a vaccine, we would have to accept high mortality numbers. Historically, the fastest time frame for developing a vaccine for a novel virus was 4 years for the mumps vaccine in the 50s and more recently 5 years for the Ebola vaccine. Finding a vaccine for Covid19 poses specific challenges that scientists have not yet had to confront according to Ian Frazer, an Australian vaccine expert involved in creating the HPV vaccine. It has been difficult to make safe coronavirus vaccines, he reports, because of the unique way coronaviruses interact with the immune system. He says that one of the problems with coronavirus vaccines in the past has been that in animal models, after immunization, when the immune response targets the cells infected with virus, inflammation in the lungs was increased, creating more pathology rather than less. https://www.abc.net.au/news/health/2020-04-17/coronavirus-vaccine-ian-frazer/12146616
Researchers around the world are working hard to find a successful vaccines but we must be careful to be sure we have a safe and effective vaccine before moving to vaccinate around the world. That unfortunately is likely to be at least 2 or more years away, not months.
What about treatments?
There are currently NO proven effective treatments, but many drugs are being studied in the United States and throughout the world. Some highlights:
— Early reports of hydroxychloroquine and azithromycin in severely ill patients suggest no effect and possibly increased mortality due to cardiac toxicities. Some places have stopped using it and it is not recommended outside of ongoing clinical trials.
— Remdesivir early reports suggest some efficacy in severely ill patients. We await results of clinical trials using it in moderately ill hospitalized patients. These should be released in early May. Anecdotal reports have been promising. We expect remdesivir would be most effective early in the course of the disease as a therapy that interrupts viral replication. It is given IV.
— Convalescent plasma appears promising and ongoing studies are underway.
— Various neutralizing antibodies and immune system modulators are being studied for use later in the course of the disease when it appears that immune system dysfunction (cytokine storm) rather than viral replication plays a role in the course and severity of the disease.
What are the next step towards safely lifting restrictions?
The California governor has outlined a framework for reopening the economy and easing restrictions. He has said dates would be determined by our ability to do six things:
1. The ability to monitor and protect our communities through testing, contact tracing, isolating, and supporting those who are positive or exposed.
It is estimated we need to be able to test 60–80 thousand people daily. We are currently testing around 16,000 per day due to limited testing supplies. Efforts to expand testing capacity are underway. Public health workers are being hired to perform the tasks of case finding and contact tracing to try to limit spread of Covid19 as we lift restrictions. In San Francisco, librarians are being hired to do this work and trained by public health professionals. Apps are being developed by Google and Apple to support contract tracing but privacy concerns have been raised.
2. The ability to prevent infection in people who are at risk for more severe COVID-19 — primarily the elderly and those with underlying conditions
3. The ability of the hospital and health systems to handle surges with adequate PPE.
Given that hospitals in California currently have adequate capacity, elective surgeries will resume. Stanford is starting the week of May 4.
4. The ability to develop therapeutics to meet the demand — We are not there.
5. The ability for businesses, schools, and child care facilities to support physical distancing
6. The ability to determine when to reinstitute certain measures, such as the stay-at-home orders, if necessary.
Some experts, recognizing the severe human costs of prolonged economic shutdown have proposed strategies for lifting restrictions even if we fail to achieve testing goals, effective anti-viral treatments and a vaccine. This paper, from a public policy think tank in Austin is co-authored by the Chairman of the Department of Medicine at UCSF, Bob Wachter, MD. and is an excellent discussion integrating medical facts with the economic realities. https://freopp.org/a-new-strategy-for-bringing-people-back-to-work-during-covid-19-a912247f1ab5
Other states and countries like Sweden have taken a different approach. Here is a link to information about the Swedish method…https://www.livemint.com/news/world/sweden-says-its-no-lockdown-strategy-proving-effective-against-coronavirus-11587365383534.html
How can we protect ourselves and others?
The answer is we can’t perfectly… As we lift restrictions we are likely to see an increase in Covid19 infections. Each of us has a different tolerance for risk and willingness to restrict our activities and social connections with family and friends. It is my hope that the information provided here and available from many reliable sources will guide your choices as you assess your own personal risk and that of those around you.
How we do this will have huge ramifications for our community and our future.
Please contact me if you have any questions or I can be of help.
Take care, Kathy
On a lighter note:
Here is a link to an article providing practical suggestions for optimal mental health during the Covid epidemic from local psychiatrist and former University of Pennsylvania All-American captain of the fencing team, Danielle Kamis, MD. https://www.kamismd.com/post/finding-structure-in-chaos
Check out this ring — Oura — that tracks your sleep, breathing, activity and temperature. The company that makes this device has partnered with UCSF in a research study to see if by tracking this data and using artificial intelligence, they can predict and alert those who may have contracted SARS CoV 2, the virus causing Covid19…I have one and love it! https://ouraring.com/
For a thought-provoking and inspiring essay, check out Marc Andreessen’s piece reflecting on lessons of Covid19 https://a16z.com/2020/04/18/its-time-to-build/