COVID Vaccine and Return to Normal

Public health officials say that even after you get vaccinated against COVID-19, you still need to practice the pandemic precautions. That means steering clear of crowds especially indoors, continuing to wear a mask in public, maintaining 6 feet or more of physical distance from people outside your household and frequently washing your hands.

It takes time for the vaccine’s effectiveness to build up after getting a shot. Effectiveness is defined as not getting sick with COVID-19.

The objective of these first-generation vaccine candidates wasn’t to prevent COVID-19 transmission entirely. Instead, researchers were hoping the vaccines would prevent severe COVID-19 and deaths, and that’s exactly what Phase 3 trials showed. The Pfizer/BioNTech, Moderna, and AstraZeneca/Oxford vaccines can all prevent severe COVID-19 with varying degrees of efficacy.

People immunized against COVID-19 will have a high chance of avoiding a severe case of the illness after an actual infection, but infection with the novel coronavirus would be possible even after a person acquires immunity.

A new study from Israel indicates that the immunity developed from the Pfizer/BioNTech vaccine is so strong that it might prevent COVID-19 transmission. Researchers from the Sheba Medical Centre in Tel Aviv studied the immune response in 102 hospital staff members who received both Pfizer/BioNTech vaccine shots. They found that 100 people developed up to 20 times more neutralizing antibodies within a week of the second dose than COVID-19 survivors who went through severe COVID-19 cases. These higher levels of antibodies that would neutralize the actual virus upon actual encounter are believed to also prevent transmission.  With the higher the number of antibodies, the harder it would be for the virus to infect cells and replicate enough for vaccinated people to become infected.

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In order to put this pandemic in the rearview mirror, a large percentage of the population needs to either be vaccinated or gain immunity via an infection with the virus (a much riskier route that would include many more deaths).

When a large portion of the population has immunity to the virus because of this sort of “herd immunity,” it’s unlikely to keep spreading. Even people who haven’t been vaccinated (such as very young babies and those with compromised immune systems) are protected once this level of immunity in a population is achieved, because the illness has little opportunity to spread within the community — most people who run into the virus in this scenario are immune.

What is herd immunity?

Herd immunity (or community immunity) occurs when a high percentage of the community is immune to a disease (through vaccination and/or prior illness), making the spread of this disease from person to person unlikely. Even individuals not vaccinated (such as newborns and the immunocompromised) are offered some protection because the disease has little opportunity to spread within the community.

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Herd immunity depends on the contagiousness of the disease. Diseases that spread easily, such as measles, require a higher number of immune individuals in a community to reach herd immunity. Herd immunity protects the most vulnerable members of the population.

COVID-19 is a very contagious disease.

A large percentage of the population will need to be immune against COVID (through infection or vaccination) before herd immunity will be achieved. It is not known when that will happen, but it will depend on how many people develop immunity after COVID-19 infection, how soon a COVID-19 vaccine is widely available to the general public, and how many people get vaccinated. Throughout this time period until herd immunity is achieved, it is very important to continue to wear masks in public, to wash or sanitize your hands, and to maintain social distance to slow the spread of COVID-19.


References:

  1. https://www.npr.org/sections/health-shots/2021/01/12/956051995/why-you-should-still-wear-a-mask-and-avoid-crowds-after-getting-the-covid-19-vac
  2. https://www.nejm.org/doi/full/10.1056/NEJMoa2034577
  3. https://www.msn.com/en-us/health/medical/study-says-pfizer-vaccine-immunity-is-so-strong-it-might-prevent-covid-19-transmission/ar-BB1cTAkA?ocid=uxbndlbing
  4. https://apic.org/monthly_alerts/herd-immunity/
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