Last update: 6/18/2020
As Spring comes to an end in the Northern Hemisphere and North Americans and Europeans are hopeful that the first wave of SARS-CoV-2 is winding down, I’d like to provide an update with the current information that I can find.
Close contact, coughing and sneezing are the main avenues that the virus spreads. Physical distancing and mask wearing has been shown to be the most effective way to prevent the transmission of SARS-CoV-2. One peer reviewed study released by UC Berkeley and Cambridge estimates that these measures may have prevented 60 million or more cases in North America.
Being outside when interacting with other people reduces transmission more than being inside. Having all people wear masks when interacting with is also a main way to stop the spread. Being outside and having all people wear masks is the optimal method.
It appears that, although the virus can survive on surfaces, they are not considered a primary method of transmission. This is most likely due to the low viral load of contaminated surfaces. Physical distancing and mask wearing continue to be the best methods of slowing the spread of the virus, keeping our hospital capacity down and giving the scientific community more time to develop treatments and study the virus.
2. Long Term Damage
It is well documented that SARS-CoV-2 causes scar tissue to form in the lungs. It also causes damage to cells lining blood vessels. Damage to the cells of blood vessels is likely why so many people with cardiac conditions have been disproportionately affected by the virus. This also explains why many cases that end in death are very drawn out. These cells are the last cells that are damaged by the virus, so it takes a while for them to be affected. This is good and bad news. It’s bad because very few viruses damage the cells in this way so it is something unique about the virus. It is good because we have medications that can help protect those cells leading to more effective treatment options.
Additionally, there is mounting evidence that the SARS-CoV-2 virus can be found in the brain and in spinal fluid, resulting in neurological diseases. It is likely that the virus enters the bloodstream through the lungs and then travels to the brain. The full extent to which the virus can enter the nervous system and cause long term damage is still unknown. It is known, however, that Covid-19 can cause blood clots and strokes.
3. Blood Type
It is quite evident that O blood types are less susceptible and A blood types are more susceptible. One recent study shows that patients with A blood type are 50% more likely to need a ventilator after being admitted to the hospital. Another study also suggests that O blood types are 9-20% less likely to contract the virus in the first place. The study above may be difficult to read so here is a more readable discussion regarding both studies.
4. Vaccines and Treatments
There is currently no vaccine for SARS-CoV-2 or one specifically for treating the COVID-19 disease. There are many vaccines currently being developed and in trials. This virus is very unique to humans and there are reports of traditional vaccine methods being ineffective. A viable vaccine widely available for the world is still a long way down the road.
One promising treatment is the potential use of dexamethasone, an inflammatory steroid. A recent study done in the UK reported a 35% better chance of survival for patients needing ventilators. It reported a 20% better chance for patients needing oxygen and did not show significant results for patients with more mild symptoms. They only released a summary, so the scientific community is looking for more info. More studies are needed to prove whether it is an effective treatment option.
Medically, dexamethasone is a steroid and steroids are generally used to suppress the immune system. It is likely that dexamethasone may help patients experiencing cytokine storms in late stages of COVID-19. Steroids also tend to weaken the immune system so it may also hinder the recovery process.
There are also a number of other potential treatment options that are currently being explored and studied.
5. “Summer Effect”
It’s too early to tell how much summer weather will affect SARS-CoV-2. There is a lot we don’t know about how endemic viruses move throughout the year. We have even less data on how pandemics spread. SARS-CoV-2 is not endemic yet, it is still in a pandemic state. Pandemics generally do not subside regardless of the time of year. Currently, the overall human population still has basically no natural immunity. It is possible that higher temperatures and increased humidity will slow the transmission of the virus (based on other Coronaviruses) but this is mainly for endemic viruses – not pandemic viruses.
Summer usually means people are outside more. Indoor, unventilated areas are quite clearly the prime environments for the spread of the virus. Human behavior will probably make it harder for the virus to transmit – this is not a weakening of the virus itself, however.
Additionally, humans tend to have weaker immune systems in the winter months so this may also contribute to less Summer cases. It will probably spread more slowly in the summer months than it would in winter months but, as it is still in a pandemic state, it will still continue to spread.
More more information on how weather will affect SARS-CoV2, check out this article released by Harvard and The Center for Communicable Disease Dynamics (CCDD).
There are some very early reports on a potential weakening of the virus’s overall morbidity. This means that, in some areas, the virus may be less likely to kill people. The main area this is being seen in is a particular region of Italy. The data is very raw and mostly anecdotal but it may be a sign of hope. The problem is that SARS-CoV-2 has not had that much time to mutate (in regards to how fast it mutates) so it is unlikely that these mutations are significant. I will say, as I have posted before, viruses almost never mutate to be more deadly so we shouldn’t have to worry about that. Those thinking of the Spanish Flu of 1918 may mention fall but this was due mostly to human behavior (fall activities / less precautions) and flu viruses mutate more rapidly than Coronaviruses.
Update 6/18/2020: I have not heard any more reports of this since the original article was first written on 6/11/2020 so I would not bank on this yet.
For more information on SARS-CoV-2 mutations and how it relates to morbidity, take a look at this article.
The current hard evidence shows that the first case may have a been in November in Wuhan, China. There is, however, satellite evidence showing that the virus may have started as early as August 2019 in Wuhan. Satellite imagery shows a major increase in hospital movement and hospital parking lot congestion that began in August in Wuhan in comparison to other years. There is also evidence from China’s Baidu search engine showing a large spike in searches for symptoms like “cough” and “diarrhea” that started in August. Many following the virus closely have been very skeptical that it actually started in December so this makes sense.
More info available on the CDC website.
Based on the latest information, we should continue to take a precautionary approach to dealing with SARS-CoV-2. This means that community interactions should be limited – especially if they include talking or close contact in an enclosed space. When possible, a mask should be worn when interacting with community members.
Those with underlying health conditions, those over the age of 60 and those with a type A blood should be very cautious. People who are over 60, with type A blood and with underlying conditions are extremely susceptible to Covid-19 and should be especially cautious.
This also means that those interacting with people who meet the criteria above should distance, wear a mask and avoid interactions with those individuals when possible.
As it relates to a “second wave”, it’s still too early to tell but it is very likely that we will see one. The virus is still in a pandemic state and it is now moving rapidly through the USA, Brazil, Mexico, India and other countries.
The severity of a “second wave” will depend on how well areas prepare (changing business practices, preparing hospitals, discovering new treatments etc.), how seriously people take precautions (like physical distancing and mask wearing), as well as other factors that we just don’t have enough information on right now – such as the actual effects summer will have.
Stay safe and please don’t downplay the severity of this virus.