July 23, 2020

On Tuesday, July 21, there were no deaths from COVID-19 in Lombardy, Italy, the European epicenter of the COVID-19 pandemic. Five months after the first death on February 22, there has been a dramatic turnaround in Lombardy, and day-to-day life is returning.

Meanwhile, the COVID-19 pandemic continues to spiral out of control over much of the U.S., especially in the southern states. It is frustrating that the steps necessary to achieve disease control are very clear but are not yet being implemented. Nonetheless, we can all individually and as families and friends follow the procedures to keep ourselves safe and track all the news as we learn more and more about how to deal with the dangerous COVID-19 virus. 

How to Stay Safe — A Recap

Below are the steps that have kept people safe around the world. Periods of lockdown without travel have been required to bring high levels of infection under control. Without formal local lockdown, individuals can choose to stay safe at home.

• Avoid crowds: This is especially important indoors. Anything beyond 5 to 10 people is a crowd. As I have emphasized, this is THE single step which can dramatically limit the spread of COVID-19 with a high R or reproduction value. Avoiding crowds, together with rapid turnaround testing, aggressive tracing and quarantine, practically guarantee the shutdown of COVID-19 spread. Unfortunately, the testing and tracing strategies can only work when the percentage level of virus is low, which is not the case now in so many U.S. states. However, rapid testing can still help enormously, and avoiding crowds is a key personal safety measure to avoid exposure.

Rapid-turnaround testing, used in Wuhan, China to help shut down the pandemic starting in February and March 2020, is a fundamental tool to help control COVID-19. These tests, with an approximately 4-hour turnaround time, are broadly available outside the U.S. and are currently used by multiple countries such as Iceland to screen arriving airline passengers. They allow sensible contact tracing to occur, as well as the screening and identification of asymptomatic individuals who are highly infectious.

Rapid-turnaround testing can enable a return to many social, work and sports activities with much reduced risks. Schools could reopen with implementation of the other measures listed here. However, due cautions are required, based upon new data from Korea indicating children between the ages 10 and 19 can spread COVID-19 very much like adults. Asymptomatic spread from these children is the big concern.

• Wear a mask: The evidence is overwhelming that wearing a mask reduces the spread of COVID-19. When implemented early during community spread, deaths are reduced by 50%. Plastic shields can provide added protection if visits to the grocery store or hospital clinic or other essential activities are required. Recent data emphasize the role of aerosol spread in transmitting COVID-19 infection.
• Physically distance: This is essential whenever you are out in the community. The plastic shield, noted above, can help if space is constrained for any reason.
• Maintain a high level of personal hygiene: Frequent hand-washing after contact with high-contact surfaces, such as door knobs, touch screens, faucets, etc., is important. Regularly clean your work space and other frequently used areas. 

With these simple steps, deaths can be reduced to zero, as in Lombardy, and new infections easily eliminated by rapid testing, tracing and quarantine. Business and social life can return.

New Research That Can Make a Difference

• Urgent concern about new covid-19 mutations or strains: The COVID-19 virus is an RNA virus that is expected to continue to evolve and change in the human population. The urgent concern is that widespread infections provide an opportunity for new strains to emerge that can be more infectious, medically dangerous and potentially resistant to vaccine therapies. A new dominant strain emerged from the surge of infections in Italy and it is this strain that has proved to be the major and more infectious strain spreading across America now.

The added deep concern is that the current U.S. surge can lead to even more dangerous mutations and that having multiple strains in circulation further complicates assessment and treatment strategies. The presence of a mild strain can increase the virulence of other strains by a process called antibody [COVID-19] dependent enhancement (ADE). 

All of this knowledge truly heightens the need to not only reduce unnecessary COVID-19 infections and deaths, but to contain viral spread in the community as a life and death prerogative. It really matters for everyone.

• What is herd immunity? This is the idea that when enough people have been infected the number of new cases and the potential for further spread will drop dramatically. This is definitely true. It is calculated that about 70% of people need to be infected to get to this point of low or minimal spread. 

Currently, the maximum level of positive infections (based upon direct PCR testing of virus) in the community is between 20 to 30%. However, these percentages are being challenged based on results of antibody tests and tests of wastewater, both of which suggest much higher percentage levels of community spread. 

There are many antibody tests available, some of which are unreliable. Plus, not all antibody tests indicate immunity since they are not all neutralizing antibodies needed to fight off the virus. Antibody levels go up about two weeks after infection but depending on the severity of infection can drop off rather quickly after that and not be detected. 

We are learning more about other aspects of immunity against COVID-19, including the role of T cells and macrophages (scavenger cells which can destroy the virus).  The cellular response to COVID-19 can be overactive and produce lung damage and can also be defective in its ability to eradicate the virus. As noted below, vaccine developers are assessing both antibody responses and needed activation of the cellular immune system to help kill the virus.

Something positive is that some individuals may have prior immunity from exposure to other coronavirus infections in the past. This idea is supported by the fact that the 1918 Spanish flu pandemic stopped when documented population spread reached approximately 30%. It is assumed there was an existing degree of immunity in the remaining population that allowed the pandemic to ultimately stop.

• The bottom line: From all of this information we can say two things: 1) There is a tremendous tragedy in the current levels of community infection and deaths. Again, it is essential to shut down the infection as rapidly as possible. And, 2) We may be closer to herd or community immunity than we think. It is too soon to tell, but hopefully in areas such as New York, which had a high level of community spread, the level of immunity in the community can at least slow the spread of any new infection episodes.

Status of Vaccine Development

Two major vaccine studies were published this past week: the results of the Oxford University team and a randomized double-blind trial from China. Both showed very promising results, with acceptable safety profiles and boosting of antibody responses. The antibody responses were with neutralizing antibodies required to clear the virus. There was evidence of cellular immune responses against COVID-19 in both trials. In the Chinese trial, older adults (over age 55 years) were studied and had lower antibody responses, suggesting the need for a second booster dose. In the Oxford trial, further studies in older and/or immune-compromised individuals are required. Although both vaccines appear to be on a fast track for success, much more work needs to be done to assess the true benefit of these vaccines.

Treatment Results

There were also two important reports of treatment results this past week. The full results of the study indicating benefit with dexamethasone in patients with the need for oxygen and/or ventilator support was published in the NEJM. As noted earlier, no added benefit was seen in patients experiencing less severe infections. The second study showed significant benefit in lung disease using interferon administered in an inhaled form. This is in line with information (mentioned in a prior blog) that COVID- 19 shuts down interferon production, which is part of the normal immune response needed to kill viruses such as COVID-19. Thus, added interferon could be helpful. This initial small study is promising and results of further trials with both injected and inhaled forms of interferon are awaited.

Side Benefits of Staying Safe

As we wait out the pandemic at home, much virtual and actual work, as well as a degree of social activities, can occur. Sir Isaac Newton survived the plague in England and wrote his most important works, while Galileo lived through the plague in Italy and published his famous works about the circulation of the planets! 

As I have mentioned a few times, nature is also getting a break during the pandemic. Right now, humpback whales are doing much better as they return to Glacier Bay in Alaska with much reduced noise from ship traffic. Whales are very sensitive to sounds and do much better in a quieter environment.

So, as we work to stay safe, let’s try to keep a positive attitude. Despite everything, we can come through this together and reach a point when COVID-19 is at a low level and vaccines and/or treatments can enable us to get our lives back on track and return to society.

Be well.

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