Category Archives: Herd Immunity

Delta Variant Infecting Unvaccinated

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Only about 46 percent of the U.S. population is vaccinated. Politico

In the U.S. Midwest and South, the highly transmissible Delta variant is spreading quickly among the unvaccinated population, according to federal health officials.

But many people who are not vaccinated are also resistant to wearing masks and are ignoring recommendations to avoid crowded indoor spaces, heightening the virus spread. Only about 46 percent of the U.S. population is vaccinated, and the number of doses administered has fallen, according to the Centers for Disease Control and Prevention (CDC).

The federal government will try to convince hesitant Americans to get vaccinated by communicating the benefits of the shots. But, President Biden’s team is not confident that a new campaign will change hearts and minds of the reluctant.

Additionally, the Biden administration acknowledged that the U.S. will not reach its goal of having 70% of adults vaccinated by the July 4th Holiday.

Delta variant

New Covid-19 infections have increased by more than 50 percent over the last two weeks in under-vaccinated states. Many of the cases are tied to the Delta variant, which the CDC says now accounts for one-fifth of new infections nationwide. The Delta variant, which was first identified in India, is more infectious than previous coronavirus strains.

“Based on the data that we have right now, the Delta variant is more transmissible than Alpha,” the strain that has predominated in the U.S. this spring, said Summer Galloway, a senior adviser at CDC.

The CDC is currently in the midst of conducting studies to pin down just how well the current vaccines protect against Delta and what impact it has on the unvaccinated population, particularly children. Additionally, the CDC is studying whether the Delta variant leads to more severe infections in undervaccinated communities.

Ending COVID-19

The hope was that once the nation reached herd immunity, the virus would die out. As a result of the Delta variant, the current level of vaccine immunity is insufficient to end the pandemic in the United States.

The higher the contagion, the larger share of the population must be immune. To end the pandemic, a majority of the unvaccinated in the United States must gain immunity, and the best way is through vaccines

The good news is that recent data shows the Pfizer vaccine is nearly 90 percent effective against Delta, making vaccination one of the most effective ways to stop the variant’s march across the U.S.

The CDC continues to encourage people who are unvaccinated to wear masks and avoid crowded indoor gatherings.

Dr. Michael Ryan, executive director of the WHO’s World Emergencies Programme, said the Delta strain should make the world “more cautious, more diligent, and more dedicated to” following health protocols.

References:

  1. https://www.politico.com/news/2021/06/26/white-house-vaccination-delta-variant-496343
  2. https://www.forbes.com/sites/alisondurkee/2021/06/25/who-urges-fully-vaccinated-people-to-continue-wearing-masks-as-delta-variant-spreads-but-no-word-from-cdc/amp/
  3. https://khn.org/morning-breakout/perspectives-delta-variant-spreading-rapidly-among-unvaccinated-steps-to-avoid-another-pandemic/

Daily COVID-19 Infections, Hospitalizations and Deaths Declining

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COVID-19 Cases Are Dropping Fast. Four reasons: social distancing, seasonality, seroprevalence, and shots.

COVID-19 is in retreat in America. New daily cases have plunged, and hospitalizations are down almost 50 percent in the past month. The reason for the decline range Americans’ good behavior in the past month combined with (mostly) warming weather across the Northern Hemisphere has slowed the pandemic’s growth; at the same time, partial immunity and vaccines have reduced the number of viable bodies that would allow the coronavirus to thrive.

The current decline of COVID-19 is crystal clear.

There has been a five-week downward trend in cases, according to data collected by the Centers for Disease Control and Prevention. The highest 7-day moving average occurred on January 11, 2021 and was 249,048. The current 7-day average is 77,385 cases, which is a 68.9% decline.

Furthermore, the 24.5% decrease in the 7-day average number of daily cases reported compared with the prior week also provides an encouraging sign of recent progress. Even with these declines, however, the 69,165 cases reported on February 17 remains higher than what was seen during either of the first two peaks in the pandemic.

Daily Trends in COVID-19 Cases

The numbers of new hospital admissions of patients with confirmed COVID-19 have decreased from the national peak of 18,006 admissions on January 5, 2021 to 6,841 admissions on February 16 (a 62% decrease). The average number of daily admissions fell by 21.8% compared to the previous week.

Nationally, the number of COVID-19 deaths continue to fluctuate. There has been over 500,000 total COVID-19 deaths reported with 2,601 new deaths reported as of February 23, 2021. The 7-day average number of new deaths decreased by 9% to 2,708** new deaths per day compared to the previous 7-day period.

Why the decline?

Americans’ good behavior in the past month combined with warming weather across the Northern Hemisphere to slow the pandemic’s growth; at the same time, partial immunity and vaccines have reduced the number of viable bodies that allow the coronavirus to thrive.

According to a piece that ran in the Atlantic.:

1. Behavior: Americans finally got on board with wearing a mask and social-distancing thing.

Officials pointed to Google mobility data that demonstrated that Americans withdrew into their homes after the winter holidays and hunkered down during the subsequent spike in cases that grew out of holiday season socializing. New hospital admissions for COVID-19 peaked in the second week of January—another sign that social distancing during the coldest month of the year bent the curve.

2. Seasonality: The coronavirus is perhaps seasonal and destined to decline.

Behavior can’t explain everything regarding the decline. Mask wearing, social distancing, and other virus-mitigating habits and behaviors had some impact. But bottomline, COVID-19 is in retreat across North America and Europe. Since January 1, daily cases are down 70 percent in the United Kingdom, 50 percent in Canada, and 30 percent in Portugal. This raises the possibility that SARS-CoV-2, the virus that causes COVID-19, is seasonal.

Many viruses fare best in cold and dry conditions; they’re not well designed to thrive in warmer, sunnier, and more humid outdoor areas, Harvard epidemiologist Michael Mina told New York magazine. Each virus is a bundle of genes and protein encased in a fatty lipid molecule. This fatty shell breaks down more easily in warmer and more humid environmental conditions.

3. Partial immunity: The virus is running out of bodies to infect

The coronavirus needs bodies in order to survive and replicate, and it now has access to fewer welcome hosts. Fifteen to 30 percent of American adults have already been infected with COVID-19, according to CDC estimates.

America’s seroprevalence—that is, the number of people with coronavirus antibodies from a previous infection—is probably concentrated among people who had little opportunity to avoid the disease.

This is partial immunity among the very populations that have been most likely to contract the disease, perhaps narrowing the path forward for the original SARS-CoV-2.

4. Vaccines: Despite naysayers and a few reluctant family members, the shots work.

The vaccines are highly effective at preventing infection. But preventing infection is not all they do. Among those infected, they also reduce symptomatic illness. And among those with symptoms, they reduce long-term hospitalization and death to something like zero.

It’s simple to show why this period of declining hospitalizations should keep going. Assuming the CDC is correct that about 25 percent of adults have COVID-19 antibodies from a previous infection and add to that number the 10 percent of adults who have received vaccine shots since December, that would mean one-third of adults currently have some sort of protection, either from a previous infection or from a vaccine. Thus, sometime this spring, half of American adults should have some kind of coronavirus protection.

Although the pandemic is far from over, the U.S. has reached the beginning of the end of COVID-19 as a threat to the health-care system and the senior citizen population.

References:

  1. https://www.cdc.gov/coronavirus/2019-ncov/covid-data/covidview/index.html
  2. https://www.theatlantic.com/ideas/archive/2021/02/why-covid-19-cases-are-falling-so-fast/618041/

COVID-19 Cases Have Dropped 77% in Six Weeks

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“COVID cases have dropped 77% in six weeks. Experts should level with the public about the good news.”  Dr. Marty Makary, surgeon and professor at the Johns Hopkins School of Medicine and Bloomberg School of Public Health

Dr. Anthony Fauci, White House COVID adviser, reassured Americans that the millions of coronavirus vaccine doses delayed by winter storms in the Northeast and Texas would be delivered this week as the nation approaches the half million mark for deaths due to Covid-19.

Despite the delays in vaccine delivery, there are signs the pandemic has eased in the U.S. in recent weeks. The 7-day average for daily deaths has fallen more than a third since mid-January, while new infections are down nearly 70% since then, according to data from the New York Times. Additionally, according to data from John Hopkins University more than 498,900 people have died of COVID-19 as of Monday morning. Globally, 2.4 million people have passed due to the virus.

Dr. Marty Makary, a surgeon and a professor at the Johns Hopkins School of Medicine and Bloomberg School of Public Health, believes that the coronavirus will be “mostly gone” and ” normal life will return” by April 2021.  In an op-ed published by The Wall Street Journal, Dr. Makary argued that half of the U.S. has already reached herd immunity because there are more coronavirus cases in the country, possibly 6.5 times as many, than the 28 million that have been reported.

“There is reason to think the country is racing toward an extremely low level of infection,” Makary wrote. “As more people have been infected, most of whom have mild or no symptoms, there are fewer Americans left to be infected. At the current trajectory, I expect COVID will be mostly gone by April, allowing Americans to resume normal life.”

Dr. Makary cites observational data which shows that the majority of Americans may already be protected not only from COVID-19 but also its new variants.  He states, “My prediction that Covid-19 will be mostly gone by April is based on laboratory data, mathematical data, published literature and conversations with experts.”

“But the consistent and rapid decline in daily cases since Jan. 8 can be explained only by natural immunity,” Makary wrote. “Behavior didn’t suddenly improve over the holidays; Americans traveled more over Christmas than they had since March. Vaccines also don’t explain the steep decline in January. Vaccination rates were low and they take weeks to kick in.”

Even with daily new infections falling below 70,000 on a 7-day rolling average, the Centers for Disease Control and Prevention has warned that more contagious variants could cause those numbers to rise again.

References:

  1. https://www.newsweek.com/john-hopkins-doctor-thinks-covid-will-largely-gone-april-half-us-has-herd-immunity-1570615
  2. https://www.wsj.com/articles/well-have-herd-immunity-by-april-11613669731
  3. https://meaww.com/dr-marty-makary-johns-hopkins-surgeon-professor-claims-us-covid-mostly-gone-april-us-herd-immunity
  4. https://www.ftportfolios.com/common/contentfileloader.aspx?contentguid=2a5d4dcf-5eda-4310-8d23-af162f8fb7e9

Johnson & Johnson Vaccine

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A single-shot coronavirus vaccine from pharmaceutical giant Johnson & Johnson was effective at preventing illness, hospitalizations and deaths in global trial. But its protection against sickness was stronger in the United States and weaker in South Africa, where a worrisome coronavirus variant now dominates.

The results, once granted emergency use authorization by the FDA, would put a third vaccine on the market in the United States. A third vaccine could accelerate the ability to broaden immunity, as variants that challenge the current generation of vaccines spread across the world.

The vaccine trial was primarily designed to measure how well the vaccine prevented illness. It was 66 percent effective overall at preventing moderate and severe disease: it was 72 percent effective at protecting against moderate to severe illness in the United States, but it was 66 percent effective in Latin America and 57 percent effective in South Africa, where concerning variants have taken root.

Company officials emphasized the vaccine was 85 percent effective at preventing severe illness, and there were no cases of COVD-related hospitalization and death in people who received the vaccine. There were five COVID-related deaths in the trial, all in people who received the placebo, not the vaccine.

Johnson & Johnson is expected to apply for emergency use authorization from the Food and Drug Administration late next week. If the review follows the path of two earlier vaccine candidates, the shot could be authorized and available to the public by March.

The J&J vaccine uses a different technology than the two FDA  authorized mRNA vaccines. This vaccine employs ‘a harmless cold virus’ to deliver a gene that carries the blueprint for the spiky protein found on the surface of the coronavirus. The virus infects cells, which then follow the genetic instructions to construct a replica of the coronavirus spike.

In contrast, the Pfizer and Moderna vaccines use a strip of genetic material called messenger RNA to instruct cells to build the spiky protein found on the surface of the coronavirus. In both cases, the immune system learns to recognize the real virus by mustering an immune response to the spike.

References:

  1. https://www.washingtonpost.com/health/2021/01/29/covid-vaccine-johnson-and-johnson
  2. https://www.washingtonpost.com/health/2020/09/23/coronavirus-vaccine-jj-single-shot/?itid=lk_inline_manual_2

Herd Immunity and the Vaccine

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Herd immunity occurs when a large portion of a community ― the herd ― becomes immune to a disease, according to the Mayo Clinic. This makes the spread from person to person unlikely. As a result, the whole community becomes protected — not just those who are immune.

Two paths to herd immunity — vaccines and infection.

Vaccines create immunity without causing illness or resulting complications. Herd immunity makes it possible to protect the population from a disease, including those who can’t be vaccinated, such as those with compromised immune systems.

Herd immunity can also be reached when a sufficient number of people in the population have recovered from a disease and have developed antibodies against future infection.

Experts estimate that 70% of the U.S. population — more than 200 million people — would have to recover from COVID-19 to create herd immunity and halt the epidemic. This amount of infection could lead to serious and potentially long-term complications and millions of deaths.

Since the risk of developing dangerous symptoms from COVID-19 may be greater in people who are older (over 65) or in people of any age who have other serious underlying health problems, such as heart or lung conditions, weakened immune systems, severe obesity, or diabetes. And if many people become seriously ill with COVID-19 simultaneously, the nation’s health care system could quickly become overwhelmed.

Until there is widespread COVID-19 vaccinations, it’s crucial to slow the spread of the COVID-19 virus and protect individuals at increased risk of severe illness, including older adults and people of any age with underlying health conditions. To reduce the risk of infection:

  • Avoid large events and mass gatherings.
  • Avoid close contact (within about 6 feet, or 2 meters) with anyone who is sick or has symptoms.
  • Stay home as much as possible and keep distance between yourself and others (within about 6 feet, or 2 meters) if COVID-19 is spreading in your community, especially if you have a higher risk of serious illness. Keep in mind some people may have the COVID-19 virus and spread it to others, even if they don’t have symptoms or don’t know they have COVID-19.
  • Wash your hands often with soap and water for at least 20 seconds, or use an alcohol-based hand sanitizer that contains at least 60% alcohol.
  • Wear a cloth face covering in public spaces where it’s difficult to avoid close contact with others, especially if you’re in an area with ongoing community spread. for health care providers.
  • Cover your mouth and nose with your elbow or a tissue when you cough or sneeze. Throw away the used tissue.
  • Avoid touching your eyes, nose and mouth.
  • Avoid sharing dishes, glasses, bedding and other household items if you’re sick.
  • Clean and disinfect high-touch surfaces, such as doorknobs, light switches, electronics and counters, daily.
  • Stay home from work, school and public areas if you’re sick, unless you’re going to get medical care. Avoid public transportation, taxis and ride-sharing if you’re sick.

To reduce the spread of COVID-19, everyone needs to continue to use masks, exercise proper hand hygiene, limit travel, avoid congregating, and maintain appropriate social distancing. 

References:

  1. https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/herd-immunity-and-coronavirus/art-20486808