CAMBRIDGE — Like surfers who begin to look out for the next big wave, when there was the first, epidemiologists and health leaders in the United States are preparing for a new surge of cases covid-19 at the end of this year. There are fears that in the USA this second wave may coincide with the peak of flu season 2020-2021 years, triggering a new influx of hospital patients in dire need of artificial support of respiration.
These fears are justified, judging by what we know about the coronavirus and influenza. In both cases, the number of infected begins to rise in November and reaches its peak at some point in December, January or February, before you go on the decline — is already closer to April.
However, less clear with the question, how high will the waves of each of these infections. We understand the epidemic patterns of influenza is much better than the virus SARS-CoV-2, are the cause of the disease covid-19. However, influenza also remains a known unknown. It strains every year varies according to level of infectivity and severity. In some years the number of deaths from flu in the United States can be low — about 12 thousand. However, in the winter of 2017-18 years were especially lethal strain that caused the death of approximately 80 thousand Americans. This was the highest figure for the last 40 years.
Annual variation in strains of influenza indicate that we need each year to create a new vaccine. There’s only one problem: the vaccine should be prepared well before the peak of flu season, and often even before there is a new strain. When the vaccine is accurately suited to the current strain, it helps to limit the severity of the disease caused by the infection, and the number of deaths due to complications of the disease.
But our vaccine for 2017-18 years was not very appropriate. By January 2018, the hospitals were overcrowded; emergency Department refused to accept patients arriving by ambulance; and medical centers have introduced measures that today seem to be already familiar to mobile points of reception of patients in Parking lots, restriction of visits by friends and family members, the cancellation of elective surgical operations.
And therefore the severity of the flu season 2020-21 years will depend on how well our vaccine suitable for future strain of the virus, as well as the characteristics of this strain. However, it will also depend on our own conduct and our willingness not to spread the infection among others.
In comparison with influenza viruses, the behavior of the coronavirus SARS-CoV-2 remains unknown much more. Our conclusions are mainly based on studies of the behavior of the four coronaviruses that cause respiratory illness and is circulating in the U.S. since, at least since the 1960s when they were first opened.
The seasonal appearance of these viruses is very similar to the behavior of the flu, but there is a difference: the cases of infection do not disappear in the summer months, they are still being found, although with reduced frequency. The assumption that heat and humidity can destroy the virus SARS-CoV-2, is refuted by the fact that in Singapore and littoral States of West Africa the epidemic continues.
Moreover, seasonality of viral infections in General remains a mystery. Some think that viruses like flu and the coronavirus, peak in the winter because cold, dry weather dries the mucous membrane, increasing our vulnerability to viral infections. And others think that we are going in winter, often indoors, which simplifies the process of infection.
These theories look convincing just as long as we do not look at other viruses, whose peak is in the summer, for example, poliomyelitis and respiratory illness-causing rhinoviruses. Mystique will only get worse, if we think of the viruses that are seasonal in temperate climates, but remain almost constant (albeit lower) level of morbidity in the tropics.
The virus SARS-CoV-2 is unlikely to disappear by itself, and effective preventive vaccine or cure does not yet exist, so the main factor determining the magnitude of the second wave of infection, will be our success in curbing the epidemic now until the beginning of this wave. The number of people who will actively infected with the virus in October (the so-called human reservoirs of the virus), will depend on the size and speed of the expected new wave of the epidemic. If you limit the number of infections today, and reduced the number of infections in the future.
Unfortunately, the U.S. does not hinder the infection сovid-19 sufficiently to avoid a severe second wave. Applied measures of anti-epidemic control (limited testing and, as a rule, voluntary self-isolation of those who are infected or have been in contact with sick) is unlikely to eliminate the virus from the population. In countries where it is still observed the success of the fight against this disease, is conducted much more extensive testing and operate programs attentive tracking of the chain of infection, allowing it to identify anyone who may be potentially infected. These people then send in special security centres (usually a local hotel), where you are monitoring their symptoms.
As in American cities is mitigated by the quarantine and behaviors become more free, we will inevitably face the consequences of our lack of action. I expect that come October, we find ourselves on the threshold of a new round of deadly infections covid-19. And if we simultaneously inflated big wave of infections with the flu, it kills more people.
Medicines prevent infection with SARS-CoV-2 will reduce the size of the second wave covid-19 and caused it damage. Thanks to the active support of governments, pharmaceutical and biotech industries as well as non-profit foundations, working to create vaccines and drugs to block transmission of the virus, conducted at an accelerated rate in laboratories around the world. Today, clinical trials for seven of the vaccines and at least one drug with preventive potential, so I’m sure that in the near future we will be able to limit the rate of infection with SARS-CoV-2.
But the question is, when exactly it will happen. If we want to effectively affect the second wave of the epidemic in the U.S. this fall, then a vaccine or preventive medicine should be widely available to the beginning of the season. This would require a very coordinated efforts of researchers, manufacturers and regulators.
This scenario is possible, but we need to be very clever and lucky to avoid all that prepared for us the nature for the coming winter. And unless a medical breakthrough happens, we have to prepare for the worst.