Paper and Threads

The Phase 3 trials of the mRNA vaccines assessed efficacy by testing participants who developed symptoms of Covid-19 and tested positive.  This is defined as SARS-CoV-2 disease. In contrast, a positive Covid test in an asymptomatic person is a SARS-CoV-2 infection.  The vaccine efficacy was 95% in preventing symptomatic disease so vaccine breakthrough cases are expected. Theoretically 5% of fully vaccinated people could develop symptomatic Covid-19 even though fully vaccinated.  No vaccine is 100% effective at blocking an infection in all circumstances.  In addition, there are immunosuppressed patients, congenital or acquired, who are at greater risk.

Breakthrough cases in people 2 weeks after their second dose of mRNA vaccines may be detected just because they are being tested regularly.  Asymptomatic infections do occur and even symptomatic disease tends to be mild after full vaccination.  The vaccine efficacy against severe disease with hospitalization and death was even higher in the phase 3 vaccine trials, but now real world deaths are being seen in fully vaccinated people, many with underlying co-morbidities.  Preliminary data in the US, over the last 6 months, suggests that 99.5% of deaths from Covid-19 have were in unvaccinated people.  See Below 

As of July 6th the US CDC reported 5,186 cases of severe breakthrough infections in 157 million fully vaccinated people for a rate of 0.003% (4909 hospitalizations and 988 deaths). The vaccines are even demonstrating efficacy against the current variants of concern.  Genomic sequencing by the NYC DOH demonstrated that 44% of the Covid cases here were due to delta variant in data released on June 26 and 69% in data released on 7.3.  The infection rate is increasing in almost every state as the virus infects the unvaccinated - NYC and NYS cases were approximately 0.5% at the end of June and approximately 1.3% yesterday (80,000 people tested).  Other states are increasing much more rapidly and if I lived in a state or county in which the vaccination rate is low and the infections are increasing dramatically, I would continue all precautions - even wearing a mask indoors in group settings unless everyone was vaccinated.  The pandemic is not over.

Posted by Shirley at 11:22 AM | Permalink | Comments (0)

Monica Ghandi from UCSF wrote a new Opinion piece in the Washington Post this week and it is worth the time to review some of the main points, since the Delata Variant is now the predominant variant in the US.  "The vaccines work against this frightening new variant, and they remain our best, most powerful tool to extinguish the pandemic here and abroad."  This variant has increased transmissibility, but there is no evidence that it causes more severe illness.  All 3 vaccines in the US produce strong neutralizing antibody responses against it and the mRNA vaccines stimulate creation of memory B and T cells as part of the immune response.  Breakthrough cases are also usually mild.  See Below

Israel reported a Vaccine Efficacy of 64% with the Pfizer vaccine, but "larger data sets from Singapore, Canada, and Britain demonstrated efficacy against symptomatic infection of 80-90%."  The number of cases in the US doubled over the last week, and most are in unvaccinated or not fully vaccinated individuals. 

Get vaccinated, get that 2nd shot if necessary, and stay healthy.  I hope to review the latest information on the J and J vaccine on Saturday.  We returned home from our visit to DC, where we were  able to watch the removal of all of the fences and Jersey Barricades from around the Capitol  Saturday - a very exciting day for everyone in the neighborhood who spend lots of time on the Capitol grounds.  

Posted by Shirley at 12:08 PM | Permalink | Comments (0)

If you are not vaccinated, you are in danger of infection by the Covid-19 delta variant.  The virus searches out the vulnerable and right now we have to be concerned about those who will never get vaccinated - as we watch Covid cases increasing in many states in the US.  Most of the cases have been occurring in the unvaccinated, and the infected group now includes a larger percentage of unvaccinated children <12 years old and a lower percentage of the vaccinated elderly.  

It is possible to be vaccinated with two doses of the mRNA vaccines and still get Covid, although severe disease is uncommon.  Both the Pfizer and Moderna vaccines had vaccine efficacy rates of approximately 95%, and slightly less with the delta variant.  And J and J just reported strong persistent activity against the delta variant for a minimum of 8 months followup of their original trial subjects.  But that still leaves a small number of people who can still be infected after full vaccination.  The vaccine efficacy against the delta variant is a slightly lower than against the original virus strain (about 90% for the mRNA vaccines) allowing mostly asymptomatic and mild breakthrough cases to occur.  See Below

We each have to decide what level of risk keeps us comfortable.  For people who live in an area where cases are increasing, it makes sense to wear a mask indoors, even if you are fully vaccinated.  There is no good way to determine who is unvaccinated in some group encounters.  If you only had one dose of the mRNA vaccines, like 15 million Americans, the vaccine efficacy against the variants may be as low as 30-35% - and you should definitely protect yourself indoors and get your second dose.    I have been following the daily Covid cases in NY State, NYC, and Manhattan.  They now test almost 100,000 people per day as part of the Statewide Tracking Program and there are <0.5% positive cases in all 3 areas.  Genomic sequencing data of new cases is still being done in NYC on a subset of cases, and the delta (Indian) variant is increasing quickly as the alpha (UK) variant is decreasing.  Our family of 16 is all vaccinated except for 3 grandchildren less than age 12 - and my husband and I still avoid high risk indoor events. 

Posted by Shirley at 3:11 PM | Permalink | Comments (0)

The immune system is incredibly complex.  An antigen, foreign to the body, stimulates an immune response consisting of antibody production against the "invader," and activation of specific immune cells. Vaccine efficacy measures the full immune response and is measured by the number of people who get Covid 19 in the placebo group and those that get covid 19 in the vaccinated group.  B lymphocytes and plasma cells are responsible for antibody production and T helper and T killer cells are part of the cellular response to the infection, or in this case vaccine.  Antibody levels can be measured, but the titer slowly decreases over time.  However some committed B cells become memory B cells and remain in clusters in germinal centers of the lymph nodes.  Some memory plasma cells also remain after the foreign antigen is gone.

If that same foreign invader returns, these immune memory cells can be activated and stimulate another full immune response to the same virus or spike protein in the vaccine.  How long will it last last?  Sometimes for life (measles vaccine).  Investigators from Wash U. in St. Louis just published a scientific paper in Nature which demonstrates that there are both the memory B cells and memory plasma cells in active "germinal centers" in lymph nodes and they still appear active 15 weeks after vaccination.  Germinal centers in lymph nodes typically peak 1-2 weeks after vaccination and then wane.  The bottom line is exciting - we may have vaccine-induced immunity that will be more durable than was expected!  How long is unknown, but the investigators now have a way to monitor the immune response in addition to measuring antibody titers.  See Below

In the words of the scientists reporting this data, "the studies demonstrate that SARS-CoV-2 mRNA-based vaccination induces a persistent germinal center B cell response, enabling the generation of robust humoral immunity."  More variants could change all of this, but right now we can hope that booster shots will not be needed for the foreseeable future.

Posted by Shirley at 6:21 AM | Permalink | Comments (1)

We had a wonderful long family weekend with two of our children and their families.  It was so nice to be with some of our grandchildren that we only saw from a distance until we were vaccinated and some of them were too.  But our oldest grandchild had already started his camp counselor job and was missed.  My husband and I took AM beach walks, and on other days walked around this charming village.  In several weeks we will see our 3rd child, his wife, and 2 grandchildren in DC - and our last trip to visit them was early January 2020.  We are so happy to finally be able to travel a little. 

These are two more of the pen/ink drawings I did earlier in the pandemic when walking around our neighborhood.  Still not painted! I love drawing hats that change regularly in a local hat store.

 Favorite Dog Attire from our neighborhood "dog fashion store."

Posted by Shirley at 3:50 PM | Permalink | Comments (0)