South African Medical Research Council Vaccines and Infectious Diseases Analytical Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; and African Leadership in Vaccinology Expertise, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
S Afr Med J. 2021 Aug 5;111(9):852-856. doi: 10.7196/SAMJ.2021.v111i9.16005.
Mutations of SARS-CoV-2 have been associated with increased transmissibility and occasionally reduced sensitivity to neutralising antibody activity induced by past ancestry virus infection or current COVID-19 vaccines. Nevertheless, COVID-19 vaccines have consistently demonstrated high efficacy and effectiveness against COVID-19 severe disease, hospitalisation and death, including disease caused by designated variants of concern. In contrast, COVID-19 vaccines are more heterogeneous in reducing the risk of infection and mild COVID19, and are modestly effective in interrupting virus transmission. Ongoing mutations of SARS-CoV-2 resulting in increased transmissibility and relative evasion of neutralising antibody activity induced by past virus infection or COVID-19 vaccines are likely. The duration of protection induced by COVID-19 vaccines is modelled to be relatively short in protecting against infection and mild COVID-19, but is likely to be 2 - 3 years against severe disease. Current experience from the UK and Israel demonstrates that even with high levels of COVID19 vaccine coverage (>85% of the adult population), resurgences with new variants of concern remain a strong probability. Nevertheless, such resurgences are not mirrored by high rates of hospitalisation and death compared with what was experienced in relatively COVID-19 vaccine-naive populations. Even though COVID-19 vaccines are unlikely to result in a herd immunity state, their ability to protect against severe COVID-19 and death could allow for a return to normalcy once a large enough proportion of the adult population in a country has been vaccinated.
SARS-CoV-2 的突变与增加的传染性有关，偶尔也会降低过去的病毒感染或当前 COVID-19 疫苗引起的中和抗体活性的敏感性。然而，COVID-19 疫苗在预防 COVID-19 严重疾病、住院和死亡方面始终表现出很高的疗效和有效性，包括由指定的关注变异株引起的疾病。相比之下，COVID-19 疫苗在降低感染和轻度 COVID19 的风险方面更为多样化，在中断病毒传播方面的效果也较为温和。SARS-CoV-2 的持续突变可能导致其传染性增加，并相对逃避过去病毒感染或 COVID-19 疫苗引起的中和抗体活性。COVID-19 疫苗诱导的保护期被建模为对感染和轻度 COVID-19 的保护相对较短，但对严重疾病的保护可能为 2-3 年。英国和以色列目前的经验表明，即使 COVID19 疫苗的接种率很高（>85%的成年人口），新的关注变异株的再次出现仍然是一个很大的可能性。然而，与相对 COVID-19 疫苗接种率较低的人群相比，这些再次出现并没有导致住院和死亡的高比率。尽管 COVID-19 疫苗不太可能导致群体免疫状态，但它们能够预防严重的 COVID-19 和死亡，一旦一个国家有足够大比例的成年人口接种疫苗，就有可能恢复正常。
