Dec 5, 2024

The third wave of COVID-19 “is likely going to be the worst that we have seen thus far over the course of the pandemic,” Toronto’s top doctor Dr. Eileen de Villa told the city’s Board of Health in an update. (Credit: Francine Kopun, Jennifer Pagliaro. Toronto Star. April 12, 2021)

[Ed’s Note: In February 2020, CFNet started publishing Dr. Rey Pagtakhan’s column, Medisina at Politika, on COVID-19.]

Now on Part 28 of his running commentary, Dr. Pagtakhan’s twice monthly column has kept the Filipino community and other CFNet readers continually informed about 1) the pandemic and its impact, 2) the scientific advances on drugs and vaccines, and 3) the effectiveness of public health responses, including mass vaccination as a vital step to individual protection and development of herd immunity (also called community or population immunity).]

Until recently Canadians were seeing the horizon of a return to near normal life and living. Four COVID-19 vaccines have been authorized for emergency use, nationwide vaccination commenced, and COVID-19 cases and deaths have become preventable. The pandemic beast would soon be tamed and a sense of optimism was high.

In less than a month since springtime 2021 began, resurgence of new cases, increased utilization of hospital beds and intensive care units, and more deaths have validated the presence of the third wave – more severe in Ontario, Quebec, British Columbia and Alberta – due to the increasing dominance of variants of concern (VOC).

Update on human toll and utilization of hospitals and ICU units: In the past week, hospitalizations rose 26% and utilization of ICU beds rose 19%. As of April 13, the cumulative cases and deaths for Canada according to the Johns Hopkins University Coronavirus Tracker were over a million (1,078,482 cases) and 20 thousand (23,336 deaths), respectively, with the daily average of 8,621 cases and 36 deaths for the preceding week an increase of 33% and 28%, respectively. Except for New Brunswick and the territories, the increases in human toll were spread across the country – the red flag for a third pandemic wave.

 

Magnitude of COVID-19 VOC and why they are formidable foes?

Referring to the third wave now in “full bloom,” the Globe and Mail editorial of March 31st said: “A March that came like a lamb and went out like a lion…the country is effectively in a new pandemic, as new variants displace our reliable old.”

The Public Health Agency of Canada and provincial health authorities have been tracking the gravity of these three variants nationwide (CTV News, April 12th): (1) B.1.1.7 – 33,720, (2) P.1 – 1,218, and (3) B.1.351 – 357. The highest was in Ontario (16,761), accounting for about 70% of the provincial total cases, and in Alberta (10,770); less in British Columbia (4,111) and the rest of the provinces. These occurrences parallel the severity of resurgence seen among the provinces. The doubling rise in P.1 variant – first detected in Brazil – in British Columbia, Ontario and Alberta is extremely concerning because of its propensity for quick spread.

These VOC are more formidable foes than the original version of SARS-C0V-2. They carry a 63 per cent higher risk of hospitalization, 103 per cent higher risk of intensive care unit admissions, and 56 per cent greater risk of death. However, whether they make people sicker than the original strains of the virus do is not settled. Their utilization of the healthcare system – facilities and staff – is enormous and fast, creating real “moral distress."

Younger people in their 20s, 30s, and 40s have been more affected now. Substantial numbers of outbreaks with B.1,1,7 have occurred in schools. The risk of this variant to children and to their families, may also be due to inability of children to maintain social distancing and masking and to avoid contact sports. Schools and daycare are obvious situations for close contact transmission and subsequent spread at homes – a challenge to maintain in-class learning and meet the increasing demand to reopen schools.

Binding more tightly to the ACE2 receptors provides selective advantage to the variants. The B.1.1.7 and the B.1.351 variants bind to the ACE2 receptor binding domain at two-fold and five-fold greater affinity, respectively. This greater affinity helps explain why these VOC are more transmissible and transmit for longer periods of time. The B.1.1.7 variant also carries so-called ‘deletions’ type of mutation because it eliminates part of the genetic code and, as a result, helps this variant to escape antibodies produced during the body’s immune response to an infection. Moreover, it can make commercial testing kits to give false negative results by failing to detect its spike protein gene. A looming new risk is the identification of so-called double mutant.

 

What forces could have led to resurgence:

A number of forces may have been at play: 1) large gatherings at super spreader events,2) vaccination has not been optimal, 3) letting one’s guard down after receiving the first vaccine dose, 4) premature lifting of public health restrictions and delay in re-imposing them; 5) conflicting messaging over vaccines, 6) distrust of leaders,  7) inconsistent enforcement of existing health measures, and 8) pandemic fatigue. How much each of the possible forces contributed to the resurgence is not clear.  What is clear is the devasting human toll the VOC have exacted with their ability to spread and to affect the younger of our generation. Knowing these forces could help inform the design for an exit plan.

 

Outline of exit plan from the third wave:

World pandemic expert Dr. Anthony Fauci, Chief Medical Adviser to US President Biden, speaks of two key things for exit (CNN News. April 3rd):"A, keep pushing down and doubling down on public health measures; and B, do whatever you can to get as many people vaccinated as quickly and as expeditiously as possible."

 

Status of public health guidance

Ostensibly, our hope to have every Canadian vaccinated (before a third wave) had vanished.  The challenge now is to comply with safety restrictions until our vaccine rollout keeps pace with the exponential increase in the numbers of variants. Keeping the greatest distance, avoiding congregate gatherings particularly indoors with poor ventilation, washing (not merely rinse) the hands with soap and water for at least 20 seconds, or using a hand sanitizer, avoiding touching one’s face, and wearing a best-fitting face mask cannot be overemphasized.

Public Health Canada has advised against recreational travel within the country. Lockdowns and other more restrictive safety measures have been declared in several provinces.

 

Current vaccination status:

Canada Research Chair of emerging viruses and assistant professor at the University of Manitoba Jason Kindrachuk said recently (Adam Miller: CBC News. April 3): "We have a lot of virus moving around the country and escalating very, very quickly…Vaccinations are certainly starting to pick up, but we're nowhere near where we need to be to get this thing under control."

But there are pieces of good news. As of April 13, a total of 8,583,763 vaccine doses had been administered to Canadians, reflecting vaccination of (1) 20.41% of the total population with at least one dose (7,755,670) and (2) 24.57% of the 16 years and older eligible population. About 2.15% of the population had received the two doses, lowest in British Columbia (1.71%); only slightly higher in the other provinces (from 1.86% in Newfoundland and Labrador to 4.96 in Manitoba), and much higher in the three territories (from 24.09% in Nunavut to 36.38% in the Yukon).

That close to a fifth of the total population or a quarter of the eligible vaccinees have received one dose is a remarkable achievement, considering Canada only depends on imported vaccines for supply and there were disruptions in the preceding two months. These figures place the country third among the G-7 and G-20 nations of the world.

It is also good news that the available vaccines protect children age 12 to 15, for whom application for emergency use authorization may be filed soon. In addition to protecting them directly, children comprise a significant segment for the development of herd immunity.

Moreover, Pfizer has been consistently delivering more than 1 million doses weekly for more than a month now and is expected to continue; Moderna has tried to catch-up with its delivery, too. Over the next three months, Canada expects delivery of at least 44 million doses, enough to vaccinate nearly all adults come Canada Day.

Still worrisome…need for more intensive and flexible modes of vaccination: Our success to date does not mean we should not be open to more intensive and flexible modes of vaccination. Naturally, we all worry about the remaining 28.5millions waiting to be vaccinated with one dose at least. Realize that many more – essential workers at meat processing plants, warehouses and transport companies who cannot work from home, and others in similarly difficult situations – have yet to receive their first doses.  Let us all be conscious that protecting many more of our fellow Canadians with their first dose also protects us all in the community as a whole. I am confident our public health officials and provincial and territorial governments are aiming to vaccinate their populations as “quickly and as expeditiously as possible.” 

 

How the human body responds to SARS-CoV-2 infection – a review for greater understanding:

Each SARS-CoV-2 particle, magnified in the middle of the illustration, has the characteristic spikes of protein on its surface that looks like a ‘crown.’ These protein-spikes help the virus attach to the ACE2 receptor proteins found on the outer wall of the human cells, then enter the host cell, make more copies of themselves, and trigger infection and cause disease.

In response to the virus infection, the body forms Y- shaped antibodies that bind to the spikes, marking them for destruction by the simultaneously activated T-cells.

 

Illustration of the human response to COVID-19 virus infection. Credit: KTS Design in David Cox: Coronavirus Science Coverage, National Geographic, February 4, 2021.] Illustration of the human response to COVID-19 virus infection. Credit: KTS Design in David Cox: Coronavirus Science Coverage, National Geographic, February 4, 2021.]

 

How COVID-19 vaccines teach our immune system to prevent infection and disease:

Using different approaches, the four vaccines – Pfizer, Moderna, AstraZeneca, and Johnson and Johnson (J&J) – help the body to recognize and destroy the spike proteins in the SARS-CoV-2 before it could trigger infection and cause disease.

Pfizer and Moderna vaccine makers use the messenger RNA (mRNA) approach. All they need is the genetic sequence of the COVID-19 virus – just the sequence – and not the virus itself.  They use a little piece of the ‘genetic material coding for a piece of the spike protein.’ Messenger RNA – a single strand of the genetic code that human cells can use to make a protein – instructs the muscle cells in the arm to make a particular piece of the virus's spike protein called the ‘receptor binding domain (RBD)’. Upon seeing it, the immune system recognizes it as foreign and is prepared to produce antibodies when, later, the vaccinated persons encounter the wild COVID-19 virus. That is, their immune system can “recognize” the virus and “remember” how to fight it off.

The mRNA is very fragile; hence, it is encased in lipid nanoparticles -- a coating of a butter-like substance that melts at room temperature. That's why Pfizer's vaccine must be kept at ultracold temperatures to transport and store. Moderna uses different formulations for the lipid nanoparticles and its vaccine can be transported more conveniently and can be kept stable for a month at home refrigerator temperature.

AstraZeneca and Johnson and Johnson are vector vaccines. The genetic recipe for the spike protein is carried into cells by a genetically engineered adenovirus, which has the COVID-19 virus spike gene encoded into it. Upon entering the host cells, the vector vaccines make the cells to produce the spike protein, to which the human immune system reacts, produces antibodies and activates T-cells to destroy the cells with the spike protein.  Later, when the vaccinated persons catch the real COVID-19 virus, antibodies and T-cells are triggered and ready to fight the pathogenic virus to prevent infection and disease.

Astra-Zeneca and J&J have less onerous cold chain requirements; J&J is a single dose regimen.

The four vaccines are effective to varying degrees at preventing serious COVID-19 illness, hospitalization and death. More recent data indicate they also prevent the onset of infection. Pfizer, Moderna and J&J can protect against disease due to variants.

 

The end is definitely in sight – a race between humanity and the virus

"The end is definitely in sight, but we're not there yet," said Prime Minister Trudeau in a recent briefing. "This third wave is more serious and we need to hang in there for another few weeks to make sure that we can flatten that curve, drop those numbers down again, to give a chance for vaccines to take hold."

His is a call for collective Canadian engagement against the common pathogenic foe. Indeed, the original version of SARS-CoV-2 and its current and emerging variants are our common and formidable foes. The human toll has been enormous and shows no signal of retreat. They need the collective understanding and focus of all our people and the cohesive leadership and decisive moves, not waltzing decisions, among our political leaders to avert more COVID-19 tragedies.

No need to finger-point, to blame others, to find excuses, nor to waltz on decisions – simply acknowledge variants are our common formidable foes. It is not choosing to protect between the seniors or the young, one group or the other, the rich or the poor, the most vulnerable or the least, nor between one province and another, nor one country and another nation.

May we reflect goodwill, share empathy, feel the pains of others, the fatigue and the stress of some.

We are all in this fight together. It is a race between humanity and SARS-CoV-2 and its variants.


Editor's note: Dr. Rey D. Pagtakhan, P.C., O.M., LL.D., Sc.D., M.D. M.Sc. is a retired lung specialist, professor of child health, author of articles and chapters in medical journals and textbooks, and a former health critic, Parliamentary Secretary to the Prime Minister, and cabinet minister, including Secretary of State for Science, Research and Development. He graduated from the University of the Philippines, did postgraduate training and studies at the Children’s Hospitals of Washington University in St. Louis and University of Manitoba in Winnipeg, and spent a sabbatical year as Visiting Professor at the University of Arizona Medical Center. In June 2003, he spoke on “The Global Threat of Infectious Diseases” at the G-8 Science Ministers/Advisors Carnegie Group Meeting in Berlin.

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