The strategy to overcome attack with an ultra-short incubation period and escape with an ultra-long incubation period of the COVID-19 Delta variant of based on cases of outbreaks and their containment
	    		
		   		
		   			
		   		
	    	
    	 
    	10.19428/j.cnki.sjpm.2021.21235
   		
        
        	
        		- VernacularTitle:Delta变异株超短偷袭与超长逃逸及其防控——以真实案例探讨新型冠状病毒传播的预防与阻击
 
        	
        	
        	
        		- Author:
	        		
		        		
		        		
			        		Jia-tong ZHUO
			        		
			        		
			        		
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			        		Author Information
			        		
		        		
		        		
			        		
			        		
			        			1. Guangxi Zhuang Autonomous Region Center for Disease Control and Prevention,Nanning, Guangxi 530028,China
			        		
		        		
	        		
        		 
        	
        	
        	
        		- Publication Type:Research Article
 
        	
        	
        		- Keywords:
        			
	        			
	        				
	        				
			        		
				        		epidemic of COIVD-19;
			        		
			        		
			        		
				        		Delta strain;
			        		
			        		
			        		
				        		vaccination;
			        		
			        		
			        		
				        		quarantine;
			        		
			        		
			        		
				        		wearing mask
			        		
			        		
	        			
        			
        		
 
        	
            
            
            	- From:
	            		
	            			Shanghai Journal of Preventive Medicine
	            		
	            		 2021;33(9):869-874
	            	
            	
 
            
            
            	- CountryChina
 
            
            
            	- Language:Chinese
 
            
            
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		        	Abstract:
			       	
			       		
				        
				        	Objective:To discuss the strategy of fighting and containing COVID-19. Method:The speed of the spreading of the ordinary strain in Dalian on Dec. 15, 2021 caused by carrying cold-chain goods from a Russia-registered freighter and the Delta strain caused by imported cases in Guangzhou during May 20 to Jul. 23, 2021 was compared. Results:The incubation period of the first generation of the imported Delta strain of COVID-19 was 4 days, which was 5 days shorter than that of the ordinary strain of COVID-19; The time from the exposure to the Delta strain to spreading to the next person was 1/3 days shorter than that of the ordinary strain of COVID-19. The inactivated vaccine needs at least 8 days for recall immune response meanwhile the mRNA vaccine needs at least 4 days, which could not completely block the COVID-19 virus, especially the Delta strain, which can attack with an ultra-short incubation period. Meanwhile, some COVID-19 strains have an incubation period longer than 14 days, which was another reason for the outbreak. Conclusion:The time from the exposure to the COVID-19 Delta strain to spreading to the next person is 1/3 day shorter that of the ordinary strain of COIVD-19. Measures of full vaccination, physical quarantine and wearing masks in public should be taken to fight the epidemic of COVID-19, especially the Delta strain (or other variants) with an ultra-short or an ultra-long incubation period which can escape quarantine.