Question: Follow-up question to Saturday’s post — If having antibodies doesn’t confer immunity, then what would be the point of a vaccine? And if you can get it over and over again, are we doomed to socially distance forever?
Answer: Take heart, we are not doomed to socially distance forever! And thanks for this question, which gives me the opportunity to clarify a few things from our Q&A of 8/29:
Antibodies and immunity. To my knowledge the majority of health experts believe that antibodies do confer some degree of protection. What remains unclear is the strength of the protection afforded and how long such protection lasts. Second, because the immune system is complex, even if antibodies quickly dissipate, evidence is mounting that the protection conferred by T-cells is long-lasting (see Q&A of 5/17 and Q&A of 8/6 #Immunity). This means that even if tests do not detect any antibodies, a person may still have lasting protection — either from previous infection or from vaccination — thanks to their T-cells (for refresh on immune system, see Q&A of 5/9 #Immune Response).
Vaccines. We discussed similar questions in our Q&A of 4/25 (#Vaccines) and further discussed vaccine effectiveness in our Q&A of 7/8 (#Vaccination Effectiveness). So far, evidence that has been made publicly available on vaccination trials underway indicates that vaccinations in clinical trials are eliciting an immune response (yay!) and as summarized recently by scientists at Johns Hopkins, “Evidence from these clinical trials, and from preclinical studies in rhesus macaques, suggests that this inactivated vaccine is not associated with antibody-dependent enhancement (ADE) or vaccine-associated enhanced respiratory disease (VAERD)” (double yay!). Even if protection does wane over time, we would likely take booster shots in response. And even if we were to get infected after vaccination, we would likely become sick with a less severe form of disease (including asymptomatic infection). This article published a few days ago in STAT News, “Four scenarios on how we might develop immunity to Covid-19”, offers a nice synthesis of the lasting immunity unknowns and hypotheses. The upshot is — accumulating evidence coupled with historic experience indicates that vaccines will offer protection!
Waiting for a vaccine. As a reminder, plenty of places in the world, including New York State, have managed to get the virus under control without a vaccine. If we could get community transmission under control, we could then rely on testing, contact tracing, and isolation to monitor and curtail spread without widespread lock-down measures. This requires public health investment, community trust, and individual and social engagement (including mask wearing).