The Department of Health of Ho Chi Minh City requested the Ministry of Health to consider shortening the time interval between two doses of Covid-19 AstraZeneca vaccine from 8 to 12 weeks to a minimum of 6 weeks.
This content is mentioned in the document signed by Deputy Director of Ho Chi Minh City Department of Health Nguyen Huu Hung on September 12, with the reason that shortening the distance between the two injections to help the city speed up the vaccination rate. Covid-19.
The proposal of the Department of Health was made in the context of the complicated development of the Covid-19 epidemic in the city. As of 6pm on September 11, the city recorded 292,403 infections. The hospitals are treating 39,296 patients, of which 2,690 severe F0 are on mechanical ventilation, 23 patients with ECMO intervention and 2,914 F0 children under 16 years of age. The cumulative total number of deaths so far this year is 11,992.
By the end of September 11, the city had injected 7,776,452 doses of the vaccine, of which 6,472,848 doses were 1 (reaching 89.8%) and 1,303,604 doses of 2 were (18.1%).
The city is on the 5th day of the 7-day peak vaccination campaign, the goal is to reach 100% of the people by September 15 to receive the first dose of the vaccine. The districts are also speeding up the second injection for those who come to the schedule. injection.
The Ministry of Health has not yet responded to this proposal.
AstraZeneca is the first Covid-19 vaccine licensed and used in Vietnam. Currently, our country’s vaccination campaign is using mainly this vaccine. According to current guidelines of the Ministry of Health and documents of the World Health Organization (WHO), the manufacturer, the interval between two injections for AstraZeneca vaccine is from 8 to 12 weeks.
Pham Quang Thai, Head of the Northern Immunization Office, National Institute of Hygiene and Epidemiology: The optimal interval of AstraZeneca vaccine is observed to be about 8-12 weeks. If injected with two doses at this interval, the vaccine can be highly effective in preventing infection up to 83%, preventing severe illness and hospitalization over 90%, while vaccination before 8 weeks, the protection rate against infection is only about 71%. However, the rate of severe illness and hospitalization is not much different, still above 90%. Therefore, the manufacturer recommends two doses, 4-12 weeks apart from one dose, instead of 8-12 weeks, in order to help localities flexibly use, inject early to have early immunity against severe disease and hospitalisation. instead of waiting for optimal immunity.
A study by a group of 81 British scientists published in the Lancet Medical Journal in February 2021, said that when two injections are given less than 6 weeks apart, the effectiveness of the AstraZeneca vaccine is 55%, given 12 weeks or more apart. , the efficiency is 81%. In addition, after a single dose of highly effective vaccine in the first 3 months, it was 76% effective from 22 days after injection.
Lead author of the study, Professor Andrew Pollard, University of Oxford, UK, said: “Vaccine supplies are likely to be limited, at least in the short term, so policymakers must decide. how to deliver the best dose to achieve the greatest public health benefit.When supplies are limited, policies that initially immunize more people with a single dose can provide immediate population protection better than vaccinating half the people with two doses.”