Waning antibody responses in COVID-19: what can we learn from the analysis of other coronaviruses?

Abstract

Objectives The coronavirus disease 2019 (COVID-19), caused by the novel betacoronavirus severe acute respiratory syndrome 2 (SARS-CoV-2), was declared a pandemic in March 2020. Due to the continuing surge in incidence and mortality globally, determining whether protective, long-term immunity develops after initial infection or vaccination has become critical. Methods/Results In this narrative review, we evaluate the latest understanding of antibody-mediated immunity to SARS-CoV-2 and to other coronaviruses (SARS-CoV, Middle East respiratory syndrome coronavirus and the four endemic human coronaviruses) in order to predict the consequences of antibody waning on long-term immunity against SARS-CoV-2. We summarise their antibody dynamics, including the potential effects of cross-reactivity and antibody waning on vaccination and other public health strategies. At present, based on our comparison with other coronaviruses we estimate that natural antibody-mediated protection for SARS-CoV-2 is likely to last for 1–2 years and therefore, if vaccine-induced antibodies follow a similar course, booster doses may be required. However, other factors such as memory B- and T-cells and new viral strains will also affect the duration of both natural and vaccine-mediated immunity. Conclusion Overall, antibody titres required for protection are yet to be established and inaccuracies of serological methods may be affecting this. We expect that with standardisation of serological testing and studies with longer follow-up, the implications of antibody waning will become clearer.

Immunity after COVID-19 and vaccination: follow-up study over 1 year among medical personnel

“…This would mean that approximately 1½–2 years after infection, half of those who recovered from COVID-19 (and did not receive a booster vaccination) would no longer have measurable antibody-mediated immunity. This time course of immunity is in line with a recent study by Vanshylla et al and extrapolations from observations for other coronaviruses [ 20 , 21 ].…”

Duration of effectiveness of vaccines against SARS-CoV-2 infection and COVID-19 disease: results of a systematic review and meta-regression

“…The finding is consistent with immunological data showing that over time, amounts of most vaccine-derived antibodies, including those that neutralise the virus, decline. 39 , 40 Yet, because the immune system forms memory cells that can be activated upon exposure to a virus and includes cellular immunity, it is not clear whether this observed antibody decay results in diminished vaccine efficacy or effectiveness, and if so, over what timeframe and against which outcomes. Nevertheless, further support for possible waning immunity comes from evidence showing that after giving a booster dose the vaccine efficacy or effectiveness increases compared with people who had only received the primary vaccine series.…”

SARS-CoV-2 Spike and Neutralizing Antibody Kinetics 90 Days after Three Doses of BNT162b2 mRNA COVID-19 Vaccine in Singapore

“…Although further studies are required to fully demonstrate the antibody decay after the booster dose at >180 days later, the half-life of both antibodies post-booster is still robust (44 days for S-Ab, 58 days for N-Ab), and are estimated to return to pre-booster levels after 8-11 months. Indeed, some estimate that the antibody responses after natural infection/vaccination may last for only 1-2 years [22], with other studies [23] demonstrate that at 180 days after the second BNT162b2 vaccination S-Ab titers were similar to those in persons vaccinated with only one dose of vaccine, or in COVID-19-convalescent individuals. Thus, booster doses would be important to maintain a prolonged antibody response beyond the period of raised antibody titers >180 days after two doses of vaccine, even if some waning is demonstrated by 90 days post-booster.…”