Category Archives: Coronavirus

Antibody Testing For COVID-19

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There’s a lot of talk about antibody levels as a measure of immunity against COVID-19 after infection or vaccination. This clashes with the knowledge that the immune system remembers prior invaders and can be reactivated if there is a new exposure. 

Antibodies are proteins the body uses to recognize foreign substances that should not be in your blood and flag down immune cells to destroy the invader. When a pathogen, such as a virus or bacterium, enters the body, the immune system is triggered to produce more antibodies. Vaccines often work by introducing an unharmful or artificial part of a pathogen into your body to make it produce antibodies. The level of antibodies may wane, but the B-type immune cells remember and can ramp up production of the invader returns. 

 Antibody tests detect whether a specific antibody is currently circulating in your body which is generally considered a marker of recent infection of immunization. Initially, COVID-19 antibody testing was used as one measure of whether or not a person had been infected with the virus. However, because it can take 1 to 3 weeks after the initial infection for antibodies to be measurable in your body, the tests are not used to detect a recent or active infection.  

The way antibody tests are often discussed in the media gives the impression that circulating antibodies are a measure of immunity against the virus. The real measure is whether or not your immune system is capable of mounting a new response to the virus, not whether a response is currently underway.  Circulating antibodies are a marker of an active immune response. 

So, antibody testing cannot tell you if your body is capable of producing an effective immune response against COVID-19. You may be able to mount a strong response even if you have no measurable antibodies in your blood.   

 

https://www.cdc.gov/coronavirus/2019-ncov/lab/resources/antibody-tests.html

https://www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fvaccines%2Fcovid-19%2Finfo-by-product%2Fclinical-considerations.html

https://www.mayoclinic.org/diseases-conditions/coronavirus/expert-answers/covid-antibody-tests/faq-20484429

https://jamanetwork.com/journals/jama/fullarticle/2785530?guestAccessKey=63cc3fb6-a5f2-4a8c-af81-12e27cce9e77&utm_source=silverchair&utm_campaign=jama_network&utm_content=covid_weekly_highlights&utm_medium=email

How were the COVID-19 Vaccines Developed So Quickly?

What does it take to supply COVID-19 vaccines across the globe? Here's how  the leading players are working it | FiercePharma

Image from fiercepharma.com

Emily Samson

On March 11th, 2021, a year after the World Health Organization had officially declared the COVID-19 pandemic, one in ten Americans had been fully vaccinated. In the past, vaccine development has taken up to 10 to 15 years. The COVID-19 vaccine was developed and administered in less than one year. How was the vaccine developed so quickly?   

The main reason is that the vaccine was designed based on decades of advanced research. For  years, scientists have been studying similar coronaviruses, such as SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory System), and they were already familiar with the way the virus worked. The mRNA technology used in both the Pfizer and Moderna vaccine has been in the works for 10 to 15 years.  As soon as the virus’ genome was known, that knowledge could be immediately applied to developing an mRNA-based vaccine.  

Tests of safety and efficacy are often the slowest part of the vaccine development process. It requires three phases of clinical trials that involve an increasing number of participants and costs. Recruiting participants and raising money for testing can take vaccine developers years. However, the urgency of the COVID-19 pandemic led to strong funding, and the massive number of infections greatly increased the speed of this process. Usually, each of the three phases of clinical testing happen one after the other, because vaccine developers do not want to spend money on testing if a vaccine is not successful in an early phase. However, for the COVID-19 vaccines, all three clinical phases happened simultaneously, because billions of dollars were invested in development efforts and a large number of participants were willing to participate in testing trials.  

As with every other FDA-approved vaccine, the COVID-19 vaccines were tested with tens of thousands of participants before decisions were made regarding safety and effectiveness. All approved vaccines have met the FDA’s rigorous standards for emergency authorization and are being continuously monitored as they are administered to the public. The efficiency of the COVID-19 vaccine development is the culmination of many prior accomplishments and a testament to science and collaboration. 

 https://www.nature.com/articles/d41586-020-03626-1

 https://www.nebraskamed.com/COVID/were-the-covid-19-vaccines-rushed

https://www.medicalnewstoday.com/articles/how-did-we-develop-a-covid-19-vaccine-so-quickly

Masks and Social Distancing After Vaccination

Why You'll Still Need to Wear a Mask After the COVID-19 Vaccine

Image from prevention.com

Prachi Shah

The COVID-19 pandemic has been ongoing for almost a year. Fortunately, vaccine distribution is underway, which has given many people new hope for the end of the pandemic. However, experts say that even after vaccination, individuals should continue wearing masks in public and social distancing from those outside of their household. 

First, it’s important to understand that no vaccine provides everyone complete immunity.  Studies show that the current vaccines limit infection with symptoms; scientists are unsure of the extent to which it prevents infection altogether. The prevalence of asymptomatic COVID-19 in vaccinated individuals is unknown. We wore masks and kept our distance prior to the vaccine just in case we or someone around us was an asymptomatic carrier, and we don’t yet have the data to know whether or not this risk is reduced. [1]

You may be wondering how a vaccine can reduce symptoms but not prevent infection. Administration of the vaccine is like giving your body a “practice run” of what to do if it encounters the real virus. The body will see the particles of the vaccine and produce proteins known as antibodies, which will tag the particles and mark them for destruction. After destroying the harmless vaccine, the antibodies will remain in the body, where they will be ready to target the real SARS CoV-2 (coronavirus) if and when it enters the body.

The vaccine is administered to muscle tissue, and it produces antibodies that can circulate to the rest of the body through the bloodstream. However, the coronavirus is most easily spread through respiratory droplets and primarily attacks cells in the nose, windpipe, and lungs. The moist environment of the nose and respiratory tract is the perfect place for it to reproduce. In the case of exposure of the respiratory tract to the virus, the antibodies may not have reached all the way to the nose to prevent the initial infection (and subsequent spread via droplets), even though the antibodies will prevent the virus from taking hold deeper in the tissue [2][3].

As with all information regarding this virus and its characteristics, it’s important to note that the available information is changing each day. If it seems like experts are “changing their minds” on a recommendation, it’s likely because new research has come to light that changes our understanding of the virus and therefore changes the best practice. As this virus and vaccine are both so new, it’s safest to err on the side of caution and trust the experts when they advise to keep the mask on for now. 

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

https://www.nytimes.com/2020/12/08/health/covid-vaccine-mask.html

https://www.sciencemag.org/news/2020/04/how-does-coronavirus-kill-clinicians-trace-ferocious-rampage-through-body-brain-toes