EnMed Update: COVID-19 Vaccines are near!
The pending approval and distribution of the Pfizer and Moderna mRNA COVID19 vaccines has major implications for the proper use and interpretation of COVID19 antibody testing. Here are some FAQ’s that should help explain what you need to know.
These two vaccines contain no virus parts at all – making them the first of their kind for mass distribution.In the past all vaccines worked by giving you parts of a virus that hopefully wouldn’t reproduce inside you or make you sick – but would trigger an antibody response that protected you from the “real thing.” These mRNA vaccines trick your own body into making a part of the virus – and then you make an antibody response to that particular part – the so-called “spike protein” -that also keeps the “real thing” from infecting you.
This mRNA technique has plusses and minuses.On the plus side large quantities of mRNA are relatively easy to make quickly.Quickly is good.People are dying.And there is no worry of mRNA infecting you.
On the minus side mRNA `melts’ – becomes inactive -unless kept at very low temperatures.So work is still continuing on vaccines that work the `old-fashioned way’ – with bits of the virus.These kind of vaccines- like the COVID19 virus itself, unfortunately – tend to be stable near room temperature. They will be very suitable for use in areas where high-tech refrigeration is not easy to come by.
Antibody testing – which is not designed to test active infection, but rather to document past infection as well as immunity status – will come into its own once vaccination begins.
Two major groups of people will need antibody testing:
1) Those who already have been diagnosed with COVID19. If they have high enough COVID19 antibody levels, they may not even need to be vaccinated – or they may just get pushed to “the back of the line.”
Reinfection with COVID19 in the presence of good antibody levels is extremely rare – if it happens ever.
2) Some people tend not to make much antibody – even if their own body is the source of the viral part they should be reacting to. People in this group are considered to be `immunocompromised.” They may include those over 65 years of age; folks receiving biologic agents for auto-immune diseases such as rheumatoid arthritis, lupus, ulcerative colitis, and Crohn’s disease; anyone on steroid therapy; those receiving chemotherapy for cancer; and those who have received donor organs.
Such people will need to have antibody levels checked after vaccination to be sure that they have responded to the vaccine, and are safe from COVID19 infection.