Social distancing, wearing face masks and handwashing should continue alongside vaccines to protect people from Covid-19, experts have suggested.
Researchers made the conclusions after analysing studies that assessed the effectiveness of global public health measures in reducing rates of Covid-19, SARS-CoV-2 transmission and Covid-19 mortality.
The peer-reviewed paper, which has been published in the British Medical Journal, examined 72 studies, of which 35 evaluated individual public health measures and 37 assessed multiple public health measures.
Of the 35 studies of individual measures, 34 were observational and one was a randomised controlled trial.
They were carried out in Asia, the US, Europe, the Middle East, Africa, South America and Australia.
The researchers found that in eight of the 35 studies there was a 53% reduction in Covid-19 rates with mask wearing while there was a 25% reduction with social distancing.
Handwashing also showed a 53% reduction in Covid-19 rates but the authors say this was not statistically significant after adjusting for the small number of studies included.
Meanwhile detailed analysis for other measures - such as lockdowns, closing borders, schools and workplaces - was said not to be possible due to differences in study design, outcome measures and quality.
They added that there needs to be further assessment on those measures so that the potential negative effects on general populations can be weighed up against any positive results.
The researchers state that while Covid-19 vaccines have proved to be safe, effective and save lives, most do not give 100% protection and it is not known how vaccines will prevent future transmissions in different variants.
"Until herd immunity to Covid-19 is reached, regardless of the already proven high vaccination rates, public health preventive strategies are likely to remain as first choice measures in disease prevention, particularly in places with a low uptake of Covid-19 vaccination," lead author Dr Stella Talic, at Monash University, Australia, said.
Concluding the research, she added: "Current evidence from quantitative analyses indicates a benefit associated with handwashing, mask wearing, and physical distancing in reducing the incidence of Covid-19.
"Further research is needed to assess the effectiveness of public health measures after adequate vaccination coverage has been achieved. It is likely that further control of the Covid-19 pandemic depends not only on high vaccination coverage and its effectiveness but also on ongoing adherence to effective and sustainable public health measures."
The study was conducted by researchers from Monash University and Torrens University in Australia, the University of Edinburgh in Scotland, and Zhejiang University School of Medicine in Hangzhou, China.