Wednesday, May 13, 2020

How Likely Is A Second Wave Of SARS-CoV-2?

Dr. Anthony Fauci has testified before a Senate committee that he is worried that there may be a serious "Second Wave" oof the current SARS-CoV-2 pandemic in the United States.  The basis for this fear is the experience over a century ago with the Spanish flu, still deadlier than the current pandemic.  It came in three full waves, and of those the second was easily substantially larger than the other two.  The lag between the first and second was several months, and as of now no nation that has had its first wave essentially ger under control has not had it under control for as long as that gap. So we are not yet in a position to see if this pandemic can or will imitate that former pandcmic.

Nevertheless, there is some evidence about the possibility of more immediate, less dramatic, second waves in the form of the number of new cases in a nation rising noticeably after having had a major decline from an initial peak.  We have now seen this in a number of nations, in a small number quite dramatically.  What is the current situation regarding this?

On May 11, the site showed graphically the time path of  new cases per day for 99 nations.  This group divides these nations into three groups: "Winning" (32 nations) that have basically gotten their numbers well down, with a few exceptions; "Nearly There" (31 nations) that exhibit a variety of patterns, although nearly all currently below their peak by some; and "Need to Take Action" (36 nations), most of which simply are steadily moving up, although a small group have flattened (includes Moldova, Philippines, Poland, Romania, Sweden, and UK) or are slightly declining from a peak (including Ecuador, Finland, and US).

Out of each of these groups there are minorities that have exhibited seeing a noticeable upturn in the number of cases after noticeably declining from a peak, with some of those only showing a modest upturn, but a smaller group showing a substantial such upturn of moving back up at least halfway towards the previous peak, with a very small number actually moving back up above the previous peak.   I shall note these particular set, but note that out of the 99 total, 16 have shown such a noticeable secondary increase, and out of those 7 that have exhibited a large such increase, with two of those moving back up beyond the previous peak.  Who  are these?

From the first group of nations, the ones supposedly "Winning" there are five that have moved up, with two of those having done so substantially.  Those moving back up by small amounts are Croatia, Lithuania, and Vietnam, while those moving up a lot, both of them on the order of halfway back to the previous peak are Jordan and Lebanon (I am not sure why these last two are in this first group).

From the second group there are 7 that have shown some second uptick, with 3 of those more substantially so. Those first 4 are Bosnia, Costa Rica, Niger, and North Macedonia, while the 3 that have moved back substantially are Burkina Faso and Kyrgyzstan, both moving up about halfway, and San Marino, the natoin with the highest per capita rate of cases of all nations and that saw a decline of nearly half that was then followed by an increase that went above the first peak but has since been declining again.

Out of the final group, "Need to Take Action," there are 4 that have seen an increase after a peak, with two of those showing substantial secondary upticks.  The first 2 are Iran and Singapore while the latter 2 are Azerbaijan, now back up to about half its former peak, and Iraq, which has moved back up itss former peak again.

Aa a broader perspective on all this I close by noting that a substantial portion of the world's 10 most populous nations are not only in the final group that need to take action, which included the US that is mildy declinging, they are simply rising solidly with little sign of flattening, with this group including Bangladesh, Brazil, India, Indonesia, Mexico, Nigeria, Pakistan, and Russia.  Clearly this pandemic has a serious way to go, even if we luck out and avoid any really enormous second waves on the scale of the Spanish flu's one, which we have not yet seen out of any nations so far.

PS: I note that Germany, Lebanon, Singapore, and South Korea have all reimposed some previously lifted lockdown rules, even though the secondary outbreaks in two of these do not even show up in this data set (Germany and South Korea).

Barkley Rosser


ilsm said...

From conversations with son (he prefaces with 'your mileage may vary' (YMMV)) who lives in metro NYC and has advanced degrees in Organic Chemistry: he is hopeful for seasonal reduction in infections and skeptical about a "second wave".

For SARS (2003) there was no "second wave". It was somewhat less contagious and the infected usually much sicker. There is no known "animal reservoir" for SARS (2003) which is consistent, so far, with Covid 19. Animal reservoirs, birds, fowl and swine, source seasonal flus.

If humans are the "reservoir" for Covid 19 then strict travel restrictions are implied, and overcoming the local spread by the non symptomatic infections. Us old (at risk) people need to stay quarantined.

Not proving an animal reservoir for Covid 19 keeps the "it came from a lab" fairy tale going, although there are suppositions/rumors that a Wuhan bio lab (WHO funded?) was actively "looking for SARS like infections" in the provinces nearby and could have gotten lax with "samples".

MERS has an animal reservoir: camels. It recurs occasionally "jumping out" of camel to humans in Arabian peninsula.

Seasonality: 3 or 4 corona virus colds have been 'observed' in the US. They have all been seasonal. Antibodies to these colds exist in the US population which may add to 'false positives' on early Covid 19 serology testing.

What could effect seasonality: there is suspicion that vitamin D (sun tanning, or he recommends >5000 IU per day) and exercise improve immune system response and may link to reduced risk of severe Covid 19. Higher relative humidity (RH) reduces virus survival in the air. UV kills more pathogens.

Seasonality, temps and RH, will not be evident in New Hampshire for several more weeks.

I doubt the virus is a one off, the reservoir is likely humans. Son's recommendation is immune health and masks.

My view of a vaccine is it needs to be out early since the effect of keeping infections down with lock downs is to delay population immunity........

An aside on early vaccine release (Moderna and Novavax, I missed the spiking share prices, are in the race): it may come to a "challenge trail" where volunteers get the vaccine and are exposed to a "weakened" live virus.

I have been supplementing Vitamin D and exercising regularly for years, and being a logistician I have a stock of masks........

My plan is to quarantine through receiving the vaccination, as I am retired and inclined to being a recluse that is not a problem for me.

There is hope in the area of treating Covid 19 patients. There are many tests on going and the application of 'big data' and super computing will assist with ferreting out the best courses of treatment, it may take a few more months of gathering and crunching the data!

Be safe and stay healthy. said...


The second wave of SARS was not a big deal, largely confined to Beijing in 2004, but it happened. Apparently pangolins were the intermediary animal for SARS from bats to humans, with pangolins being perhaps the leading candidate now, although there remain problems with it as one.

Nobody remotely serious is claiming that SARRS-CoC-2 was "Manufactured" in a lab in Wuhan or elswhere. However, what remains a possibility is that it was transfered into one of the labs there either directly in a bat or through something coming from a bat that then got accdidentally released. Those claiming this is out of the question do not have a leg to stand on.

I am making noe forecasts about vaccines, impact of temperatures, or how likely it is that we shall see a really large-scale second wave, although clearly we see some cases of it reemerging here and there as my post shows.

One more place it has reappeared, if only a few cases but enought to trigger city-wide testing, is in Wuhan itself. Of the largest population nations, only China and Japan have the virus largely under control.