Study designs
The World Health Organisation (WHO) has issued recommendations for collecting data during pandemic emergencies. These recommendations are intended to help gather information on the spread of the disease, its impact and the effectiveness of interventions.

WHO, in collaboration with technical partners, has developed several standardised epidemiological survey protocols called UNITY studies. These studies aim to support national public health and social policy interventions, promote international comparability of research, and fill knowledge gaps related to the COVID-19 pandemic. An overview can be found here.
Recommendations for study designs can be found on the following topics:
Population-based age-stratified seroepidemiological investigation protocol for COVID-19 infection
Measuring COVID-19 vaccines effectiveness
The First Few X (FFX) cases and contact investigation protocol for COVID-19 infection
Household transmission investigation protocol for COVID-19 infection
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