I have been impressed by the input from the readers of this blog. Tonight I will address three issues raised by readers.
I have been watching video of people administering the new COVID-19 vaccine. They don’t appear to be injecting it correctly and are not trying to withdraw the syringe to make sure there’s no blood return. This appears to be a problem.
This is a very astute comment. When injecting a vaccine into the arm, you want to make sure to inject it into the large (deltoid) muscle of the arm (basically the shoulder). You also should make sure you haven’t accidentally put the tip of the syringe into a vein. If you inject the vaccine into the bloodstream through a vein, it is possible to get an adverse reaction.
People administering this vaccine should always attempt to pull back on the plunger of the syringe to make sure they’re not in a vein. This possibly could be the cause of some of the adverse events reported with this vaccine.
The data from the Pfizer vaccine trial is very impressive. If I get the vaccine when should I expect that my protection from COVID-19 might begin?
The Pfizer trial was remarkable in that even before the second dose of vaccine was administered, infections in vaccinated subjects stopped. COVID-19 infections stopped occurring in vaccinated individuals about 14 days after their first shot, or about seven days before the second shot. This suggests that individuals have at least some immunity to COVID-19 infection by about two weeks after they get immunized.
This doesn’t mean that it’s OK to go out and party a couple of weeks after the first dose of vaccine, but does suggest that at least partial immunity kicks in very rapidly after immunization. This should help curtail the pandemic.
If you get immunity after the first dose of COVID-19 vaccine, why do you need the second dose? Some have suggested only giving one dose to everyone, so the vaccine goes farther.
While the FDA’s analysis suggested there is at least a 75% reduction in COVID-19 infections a week after the first shot of the vaccine, this does not take into consideration a number of factors associated with the second immunization. Protection increases dramatically after the second shot, achieving a 95% reduction in infections compared to controls and, more importantly, long-term immunity from multiple, or booster immunizations.
Therefore, while short term reductions in COVID-19 infection are observed with a single shot of the Pfizer vaccine, long-term immunity to SARS-CoV-2 is likely only possible after two immunizations.