What is the new “norm” going to look like? When can we expect it? These are good questions that do not have clear or precise answers. Clearly, as of 4-9-2020, we have not yet reached the peak in cases in Massachusetts or Rhode Island. But, even when we do reach the peak and begin the downward decline, things will never really return to what we used to consider “normal”. Why? Well, there are a number of reasons. The first has to do with the question of how we can expect the SARS-CoV-2 virus to behave. Much hope has been placed on the fact that Influenza and other Coronaviruses seem to “disappear” in the warm weather – and return in the fall. The National Academies of Science, Engineering and Medicine, in a report dated April 7th, addressed two issues: the survival of SARS-CoV-2 in relation to temperature and humidity and the potential for a seasonal reduction and resurgence of cases. After reviewing all of the existing literature, they essentially concluded that if there is an effect of temperature and humidity on transmission, that it may not be as apparent as with other respiratory viruses; they also concluded that, based upon 10 influenza pandemics in the past 250 years, some started in the winter, some in the spring, some in the summer and some in the fall. Most alarmingly, they also stated that all had peak second waves six months after emergence of the virus in the human population, regardless of when the initial introduction occurred. Thus, the hope that when the warm weather comes, we will see a marked decrease in cases is highly unlikely.
In two very recent articles and communications in the Lancet, the likelihood of a “second wave” of cases occurring in China, and any country, are directly linked to how travel restrictions, social distancing and other interventions are “relaxed” (face masks, contact tracing, surveillance, temperature checks).The risk of re-introduction of the virus into the population from overseas importation is and will be a substantial risk.
Finally, there is a third factor to consider. Something that we use in epidemiology and that you likely have heard about, R0 – the basic reproduction number; a value that tells us how many other people are likely to become infected from someone who currently is infected. For SARS-CoV-2, this number has wavered between 2 to 2.5. A recent analysis of the data from China has placed this number closer to 5.7. The U.S. data currently ranges at about 2.5. Why is this important? If we consider the concept of “herd immunity” – what percent of the population needs to have immunity to a disease in order to “protect” those that don’t from getting it. The R0 is important, because we use that in the formula to come up with the percent of herd immunity needed. For a R0 of 2.2, 55% of the population needs to have immunity; for a R0 of 5, 80% of the population needs to have immunity.
So, if we get over the hump and the appearance of new cases significantly decreases, can we return to ballgames, group gatherings, and large intermingling of people? For those who had COVID-19 and survived, the answer is “Yes”. For those who didn’t contract the disease, the answer is “No”. You see, that unless at least 50-80% of the population has had the disease and recovered, those who haven’t are still at risk, and they most likely are those that were at highest risk of having severe, life-threatening cases.
The only solution will be a vaccine that will protect at least 80% or more of those who receive it from developing the disease. That, unfortunately, is not on the horizon for quite a while. If we look at flu shots, we have rarely had an efficacy that has even closely approached this number. Thus, what we can expect as the new “norm” will be for people at high risk for a severe outcome (those with marked obesity, hypertension, diabetes, metabolic diseases, chronic lung disease [including asthma], cardiovascular disease , over the age of 60, and neurological disorders) to continue to avoid large social gatherings, continue social distancing and frequent handwashing- and probably face mask continued use.
If we let up too quickly on the measures we’ve taken, including international travel, we could very well see a “second wave” of SARS-CoV-2 infections. One of the problems is that the SARS-CoV-2 virus is not simultaneously affecting every country in the world. Peaks have not yet been reached in many countries, and in some, it has not yet begun. So, we could very well see this virus burning throughout the world for quite a while. The threat of a second wave could only be an airline flight away! So, in conclusion, what will the new “norm” look like? Nothing like what the old “norm” used to be.
If you should develop any of the symptoms of COVID-19 (cough, fever/chills/,shortness of breath, muscle aches, diarrhea, nausea& vomiting, sore throat, headache or loss of smell or taste) and are high-risk for complications, you need to contact your healthcare provider- no matter how mild the symptoms may be!